LDRD Annual ReportTable of Contents iv Sandia National Laboratories/LDRD FY 1998 Annual Report 43 From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment 44 An Investigation

Cover (Above)

Since the 1940s, Sandia has provided engineering andscience expertise to protect the nation against foreignmilitary threats. Now, national security is facing a newrange of threats, from foreign states to rogue groupswithin the nation. At the same time, the United Statesis becoming increasingly dependent on a complexinfrastructure, international in scope and vulnerable tothis new range of threats. Sandia has capabilities thatcan improve the surety (confidence that a system willperform in acceptable ways during normal, abnormal,and malevolent circumstances) of infrastructures criticalto the security of the United States. Infrastructure suretyis the new national security challenge.

Sandian Rudy Matalucci leads a group that applies suretyprinciples to make buildings safer.

(Below)

Miniature robotic vehicles for sensor deployment makepossible multiple vehicle mapping of radioactive,chemical, biological, and other characteristics. Theseintegrated technologies provide intelligent miniaturesystems for DOE and DoD applications.

Sandian Tom Weber examines a self-contained 0.5-cubic-inch robotic vehicle.

Abstract

This report summarizes progress from the LaboratoryDirected Research and Development (LDRD) program duringfiscal year 1998. In addition to a programmatic and financialoverview, the report includes progress reports from 230individual R&D projects in 12 categories.

This work was supported by theUnited States Department of Energy

under Contract DE-AC04-94-AL85000.

Sandia is a multiprogram laboratoryoperated by Sandia Corporation, aLockheed Martin Company, for the

United States Department of Energy.

SAND 99-0358

LDRD Annual Report Staff:Laboratory Directed Research & Development (LDRD) Program Manager:

Chuck Meyers, Sandia National LaboratoriesDeputy Program Manager: Cynthia Harvey, Sandia National LaboratoriesInformation Administrator: Donna Chavez, Sandia National Laboratories

Editor, Writer, Page Layout: Carol Whiddon, Technically WriteResearchers: Donna Drayer, Joy Bemesderfer & Carol Whiddon, Technically Write

Designer: Douglas Prout, Technically Write

WtTECHnicallyWRITE

1 9 9 8L A B O R A T O R Y

D I R E C T E D R E S E A R C HA N D D E V E L O P M E N T

Sandia National Laboratories/LDRD FY 1998 Annual Report 31

T H I S P A G EI N T E N T I O N A L L Y B L A N K

Sandia National Laboratories/LDRD FY 1998 Annual Report

Table of Contents

Sandia National Laboratories/LDRD FY 1998 Annual Report iii

xi “...exceptional service in the national interest.”

1 Laboratory Directed Research andDevelopment Program Review

Materials Science & Technology

9 Photonic Bandgap Structures as a Gateway toNanophotonics

10 Catalytic Membrane Sensors

10 Wide-Bandgap Compound Semiconductors toEnable Novel Semiconductor Devices

12 Ultra-Hard Multilayer Coatings

14 Scanning Probe–Based Processes forNanometer-Scale Device Fabrication

15 Molecular-Scale Lubricants for MicromachineApplications

16 Surface-Micromachined Flexural Plate-WaveDevice Integrated on Silicon

17 Smart Interface Bonding Alloys (SIBA):Tailoring Thin-Film Mechanical Properties

18 Molecular-to-Continuum Fracture Analysis ofThermoset Polymer/Solid Interfaces

19 Monolithic Structures for Nanoseparation

20 Recognizing Atoms in Atomically EngineeredNanostructures: An Interdisciplinary Approach

21 Fundamental Aspects of MicromachineReliability

22 Atomic-Level Studies of Surfactant-DirectedMaterials Growth

24 Enabling Science and Technology for Cold-Spray Direct Fabrication

25 Freeforming of Ceramics and Composites fromColloidal Slurries

26 Intelligent Polymers for NanodevicePerformance Control

26 Quantum Dot Arrays

27 Laser-Assisted Arc Welding for AluminumAlloys

28 Reactivity of Metal-Oxide Surfaces

29 Exploiting LENS Technology Through NovelMaterials

Computer Sciences

33 Gradient-Driven Diffusion of Multi-AtomMolecules Through Macromolecules andMembranes

34 Parallel Quantum Chemistry for Material Agingand Synthesis

34 Modeling Complex Turbulent ChemicallyReacting Flows on Massively ParallelSupercomputers

35 Automated Geometric Model Builder UsingRange Image Sensor Data

36 A Massively Parallel Sparse Eigensolver forStructural Dynamics Finite Element

36 Density-Functional Theory for Classical Fluidsat Complex Interfaces

38 Fast and Easy Parallel I/O for Efficient ScientificComputing

38 Novel Load-Balancing for Scalable, ParallelElectromagnetic and Plasma Physics SimulationSoftware

40 Parallel Computational Chemistry UsingConstraints

40 Massively Parallel Ab Initio Validation for ASCIMaterials Aging

41 Integrated Quantum/Classical Modeling ofHydrogenic Materials

42 Computational Methods for CouplingMicrostructural and Micromechanical MaterialsResponse Simulations

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iv Sandia National Laboratories/LDRD FY 1998 Annual Report

43 From Atom-Picoseconds to Centimeter-Years inSimulation and Experiment

44 An Investigation of Wavelet Bases forMultiscale, Grid–Based Simulation

45 The Next Generation of Teraflop Density-Functional Electronic Structure Codes

46 Methodology for Characterizing Modeling andDiscretization Uncertainties in ComputationalSimulation

47 Emergent Behavior of Large Swarms ofIntelligent Agents

48 Global Optimization for Engineering ScienceProblems

49 Dynamic Simulation of Mechanical Systemswith Intermittent Contacts

50 Parallel Combinatorial Optimization forScheduling Problems

50 Programming Paradigms for Massively ParallelComputers

51 Multilevel Techniques for Unstructured GridProblems on Massively Parallel Computers

52 Scalable Tools for Massively ParallelDistributed Computing

52 Massively Parallel Methods for Simulating thePhase Field Model

53 Visual Explanation and Insight

Electronics & Photonics

57 Advanced Concepts for High-Power VCSELsand VCSEL Arrays

58 Wafer Fusion for Integration of SemiconductorMaterials and Devices

58 Highly Parallel, Low-Power, PhotonicInterconnects for Inter-Board SignalDistribution

59 Virtual Reactor for the SemiconductorManufacturing Plant of the Future

60 Selective Oxidation Technology and ItsApplications Toward Electronic andOptoelectronic Devices

61 Agile Prototyping of MicroelectromechanicalSystems (MEMS)

62 Midwave-Infrared (2–6 µm) Emitter–BasedChemical Sensor Systems

62 A Novel Nondestructive Silicon-on-InsulatorNonvolatile Memory

64 Integration of Optoelectronics and MEMS byFree-Space Microoptics

65 Advanced Laser Structures for Short-PulsedPower in Active Optical Sensor Systems

66 Metal Micro-Heat-Pipe Substrates for High-Power-Density Electronics

66 Vacuum Encapsulation of MEMS Structures

67 Massively Parallel Sensor Arrays for VolatileOrganic Detection

68 Integration of Microsensor Technology into aMiniature Robotic Vehicle

68 Precision-Formed Micromagnets

70 Agile Dry Etching of CompoundSemiconductors for Science–BasedManufacturing Using In Situ Process Control

70 Time-Resolved Ion-Beam–Induced Charge-Collection (TRIBICC) Imaging

71 Compliant Substrates for Epitaxial Integrationof Dissimilar Materials

72 Double Quantum-Well Long-Wavelength Opto-electronic Devices

73 Role of Defects in III-Nitride–Based Electronics

74 Composite-Resonator Surface-Emitting Lasers

74 Ultra–Low-Power Sensors for MicrotelemetrySystems

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Sandia National Laboratories/LDRD FY 1998 Annual Report v

75 The Development of Integrated ChemicalMicrosensors in GaAs

76 Monolithic Integration of VCSELs and Detectorsfor Microsystems

77 AlGaN Materials Engineering for IntegratedMultifunction Systems

78 Post-Processed Integrated Microsystems

Phenomenological Modeling & EngineeringSimulation

81 Enhanced Vapor-Phase Diffusion in PorousMedia

82 Stress Evaluation and Model Validation UsingLaser Ultrasonics

83 Using Higher-Order Gradients to ModelingLocalization Phenomena

84 Altered Simulation Properties for TetrahedralFinite Elements for Use in EngineeringSimulation

84 Development, Implementation, andExperimental Validation of the LatticeBoltzmann Method for Modeling Three-Dimensional Complex Flows

86 Capturing Recrystallization of Metals with aMultiscale Material Model

88 Nondeterministic Modeling in EngineeringScience

88 Lagrangian Modeling of Radiative Transport

89 High-Resolution Modeling of MultiscaleTransient Phenomena in Turbulent BoundaryLayers

90 Dispersive Measurements of Velocity inHeterogeneous Materials

90 A Physically–Based Computational Method forPredicting Generalized Fracture

91 Micromechanical Failure Analyses for Finite-Element Polymer Modeling

92 Development of In Situ Diagnostics forSimultaneous Measurement of Transient GasSpecies and Soot in Large Fires

93 A Phenomenological Model for Multi-component Transport with ElectrochemicalReactions in Concentrated Solutions

94 Methodology Optimal Selection of Test andSimulation Levels for Problems InvolvingComputational Simulation

Manufacturing Science & Technology

97 Ultra-Precise Assembly of Microelectro-mechanical Systems (MEMS)

98 Laser-Spray Fabrication for Net-Shape RapidProduct Realization

99 Solution Synthesis and Processing of PZTMaterials for Neutron-Generator Applications

100 Finite-Element Meshing Approached as a GlobalMinimization Process

100 Investigation of the Impact of Cleaning onAdhesive Bond and the Process Implications

102 Application of Parallel Mechanism Technologyto Manufacturing

102 Standard Cells for MicroelectromechanicalSystems (MEMS)

103 Scripting for Video Inspection

104 Laser Wire Deposition for Fully Dense Shapes

105 High-Throughput Dry Processes for Large-AreaDevices

106 Assuring High Reliability and ProductionReadiness in Low-Volume Manufacturing

106 Advanced Machining Processes forMicrofabrication

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vi Sandia National Laboratories/LDRD FY 1998 Annual Report

107 Fusion of Product and Process Data Using Real-Time Streaming Visualization

108 Advanced Production Planning Models

Life-Cycle Systems Engineering

111 Enabling Human Skills with CooperativeAutomation

112 Automatic Generation of MultimediaDocumentation for Assembly Operations

113 Distributed Life-Cycle Models in EnterpriseSimulations to Answer System Questions

114 Immersive CAD

114 Automatic Planning of Life-Cycle AssemblyProcesses

116 Analysis of Very Large Assemblies

116 Cloud To CAD

117 Feature Reduction of Geometric Solid Modelsfor Analysis Tools

118 Ergonomics in Life-Cycle Assembly Processes

119 System Surety Life-Cycle Engineering

Information Systems

123 Content–Based Search of Geometric Databases

123 Mission Surety for Large-Scale Real-TimeInformation Systems

124 Integrated Service Provisioning in an “IPv6over ATM” Research Network

125 Virtual Desktop Engineering with IntegratedMultimedia Data

126 Scaled ATM End-to-End Encryption

126 Ten-to-One-Hundred-Gigabit/Second NetworkEnabling R&D

128 Network Surety Modeling for Wireless ATMNetworks

129 Algorithm–Based Fault Tolerance onHeterogeneous Massively Parallel Computers

130 High-Performance Commodity Interconnectsfor Clustered Scientific and EngineeringComputing

130 Low-Power, Reduced-Computation, Public-KeyProtocols

131 AVATAR—Navigating and Mining in MassiveData

Precision Sensing & Analysis

135 Sampling and Sensing Systems for High-PriorityAnalytes

136 Electrokinetic Immunoaffinity ChemicalSensors

136 Information-Efficient Spectral Imaging System(ISIS)

137 Imaging of Moving Targets Using SimultaneousSynthetic Aperture Radar (SAR) and MovingTarget Indicator (MTI) Radar

138 Automated Vegetation Height Measurement forAutomatic Terrain Mapping

138 Sparse Geophysical Networks for MonitoringDeep Targets

139 Miniature Bioaerosol Concentrator

140 Recognizing Partially Obscured Targets byCombining Multiple Data Sources UsingEvidential Reasoning

141 Computational Engineering of Sensor Materialsand Integration with a Novel Biological WeaponDetection System

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Sandia National Laboratories/LDRD FY 1998 Annual Report vii

142 Biological Weapon Detector Using BioaffinityArray Impedance Analysis with ChemicalAmplification Through Redox Recycling

142 ATR / Exploitation Utilizing Ultra–High-Resolution, Complex SAR Imaging

Environmental Sciences

147 Designed Molecular Recognition Materials forChiral Sensors, Separations, and CatalyticMaterials

148 Rapid Screening of Complex Chemical SamplesVia Capillary Array Analysis

148 Designed Synthesis of Controlled DegradativeMaterials

149 Adaptive 3-D Sensing

150 Mechanistic Models for RadionuclideDesorption from Soils

150 Development of Innovative CombustionProcesses for a Direct-Injection Diesel Engine

152 Hydrogen Production for Fuel Cells by SelectiveDehydrogenation of Alkanes in CatalyticMembrane Reactors

153 Hybrid Vehicle Engine Development

154 Aqueous Organic Sensor

154 Designed Ionophores for Liquid-MembraneSeparation and Extraction of Metal Ions

156 An Electromagnetic Imaging System forEnvironmental Site Reconnaissance

Risk & Reliability

159 Integrated Approach to Develop Microelectro-mechanical (MEMS) Reliability Tools

160 Reliability Degradation Due to Stockpile Aging

160 Precursors to Failure of Oxides and Metal Linesin CMOS Technology

162 An Extensible Object-Oriented Framework forRisk and Reliability Analysis

162 Simulation/Optimization Tools for SystemVariability Analysis

164 A Massively Parallel Microsimulation Model ofInfrastructure Interdependency

165 Reliability Predictions for AdvancedElectronics in Smoke Environments

166 Physical Models for Predicting the Effect ofAtmospheric Corrosion on MicroelectronicReliability

167 Backside Localization of Open and Shorted IC(Integrated Circuits) Interconnections

168 Security of Bulk Power Systems

National Grand Challenges

171 Science on the Microdomain

171 Cooperative, Distributed Sensing and ActionUsing Microminiature, Intelligent Agents

172 Autonomous MicroChem Laboratory(µChemLab)

Initiatives

177 Computational Methods for Predicting theResponse of Critical As-Built Infrastructure toDynamic Loads (Architectural Surety)

178 Background Radiation AnisotropyMeasurement Sensor (BRAMS)

178 Exploitation of Satellite CommunicationsSystems and Networks for IntelligenceApplications

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viii Sandia National Laboratories/LDRD FY 1998 Annual Report

179 Microcode Evaluation

179 Real-Time Image Analysis Using Field-Programmable Gate Arrays

180 Advanced 3-D Sensing and Visualization Systemfor Unattended Monitoring

180 System-of-Labs Direct Fabrication Technology

182 Poco Switch Tubes

182 Chemiresistors Based on Metal-LoadedPolymers for Solvent Spill Detection

183 Advanced Neutron-Tube Design andProducibility

183 Surface Hardening by NanoparticlePrecipitation and Atomic Clustering in Ni(Al,O)

184 Dynamical Properties of Polymers:Computational Modeling

184 Calculation and Interpretation of the Energiesthat Underlie Transition-Metal SurfaceStructure

185 Interfacial Reactions in Ceramic Systems

186 Direct Fabrication of MultifunctionalNanocomposites Via Supramolecular Self-Assembly

187 Biophotonic Materials for Optical Encryptionand Noncomputing

188 Broadening Mechanism in 2-D Excitonic andElectron Gases

188 Low-Stress Amorphous Diamond: A NewMaterial for Sensors

189 Nanoengineered Cu-Al Defects in Al: APrototype System for Corrosion

190 Novel Energy-Conversion Devices ofIcosahedral Borides

191 Ion-Mobility Spectroscopy of BiologicalMaterials

191 Direct Fabrication of Planar Solid-Oxide FuelCells

192 Visualization Tools for MEMS Designs in aVirtual 3-D World

192 Micromachining with Ultra-Short PulsewidthLasers

193 Molecular Characterization of EnergeticMaterial Initiation

194 Engineering Complex Distributed Systems

196 Global Approaches to Infrastructural Analysis(GAIA)

196 Chemical Feedstocks for the Future: OxidativeDehydrogenation

198 Laser Communication Nanosatellites

199 Accelerator Technologies for Emerging Threats

200 Collection and Data Synthesis of AtmosphericExplosion Ground Truth for Global MonitoringSystems

201 Advanced Radiation Sources: Rayleigh-TaylorMitigation Via Perturbation Reduction

201 Microfluidic Engineering

202 InGaAsN: A Novel Material for High-EfficiencySolar Cells and Advanced Photonic Devices

203 Technologies for Countering C/B Terrorism

204 Technologies for System-Level Innovations inBallistic Missile Defense

205 Aerosol Stand-Off Detection Test-Bed

206 Design and Optimization of High-PowerElectromagnetic Source Systems andEngagement Scenarios for Achieving FunctionalUpset or Damage in Specific Target ElectronicSystems

207 Real-Time Design of Improved Powder PressingDies Using Finite-Element Method Modeling

208 Development of Fiber-Laser–Based LIF forDetection of SO2

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Sandia National Laboratories/LDRD FY 1998 Annual Report ix

209 Penetration and Defeat of HardenedUnderground Facilities Using a MicroholeDrilling Robot

210 IFSAR Tree Phenomenology and CoherenceNormalization

210 Electric Launcher for Defense Applications

211 Power-Grid Reliability and Restructuring PolicyChanges

212 SAM Telemetry for Measurements WhileDrilling

212 Advanced Geosphere Transport Simulation

214 Design-for-Manufacturability Applied toPhotovoltaic Modules

214 Low-Work-Function Thermionic EmissionMaterials

216 LIGA Micromachining

216 Applied Microfluidics Science

218 Computational Simulations of Self-AssemblingMacro-Systems by Direct Fabrication ofMicroscopic Structured Materials

218 Self-Stabilizing Optical Solitons and High-Intensity Laser Plasma Channels for Diffraction-Free Propagation and Robust PowerCompression

220 Optical Communication System for RemoteMonitoring and Adaptive Control of DistributedGround Sensors Exhibiting CollectiveIntelligence

222 Low-Cost Cadmium Zinc Telluride RadiationDetectors Based on Electron-Transport-OnlyDesigns

222 Novel Materials for Hydrogen Storage

223 Inversion of Passive Electromagnetic Fields toLocate Weapons of Mass Destruction

224 Z-Pinch–Driven Isentropic Compression

225 Covert, Distributed Biosensors for UXO/CWBased on Amplified Immunoassays Conductedin Porous Inorganic Media

226 Semiconductor Filament Lasers

226 Development of Membrane Devices Using AlNand SiC Films

227 Spectral Information Content in Ion-MobilitySpectra for Explosives, Interferants, and OtherNegative-Ionizing Chemicals

228 Picosecond Particle Velocity Measurements

228 Particle-Level Modeling of Flows ofConcentrated Suspensions

229 Efficient Processing of MaterialsMicrostructures with Intelligent FeatureExtraction for Quantitative Stereology

230 Magnetic Field Profile Measurements in Wire-Array Z-Pinches by Faraday Rotation

230 Nondestructive Evaluation of Wind TurbineBlades

231 Very Small Arrays: Designing Self-AssembledSystems of Light-Antennae and ReactionCenters for Artificial Photosynthesis

232 Enzyme-Mediated Electrochemical RedoxPolymer Biosensor for V- and G-Type ChemicalWeapons

232 Novel Biosensor Fabrication Techniques

233 Enhancing Multilevel Linear Equation SolversUsing Domain Decomposition Strategies

233 Design for 100-Year-Life Prototype

234 In Situ and Ex Situ Investigations of LateralComposition

235 Approximate Methods for ComputingEigensolutions Using Automated MultilevelSubstructuring

235 Living Tissue Engineering

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x Sandia National Laboratories/LDRD FY 1998 Annual Report

237 Appendix A: Author’s Index

243 Appendix B: Project Number/Title Index

251 Appendix C: Awards/Recognition List

253 Appendix D: Project Performance Measures

265 Appendix E: DOE Critical Technologies

281 Appendix F: Major National Programs

295 Appendix G: Dual-Benefit Areas and Single- Use Categories

Sandia National Laboratories/LDRD FY 1998 Annual Report xi

“...exceptional service in the national interest.”

Science and technology are at the heart of UnitedStates industrial competitiveness, national secu-rity, energy resources, environmental quality, andleadership in fundamental and applied science.

At Sandia, the Laboratory Directed Research andDevelopment Program provides the knowledgethat drives our future. We initiate research anddevelopment that spawn the knowledge thatrevolutionized technology. Areas of emphasiscenter on our core technical competencies andthe major strategic thrusts of Sandia’s Institu-tional Plan. Leading-edge experiments that vali-date our work are constructed and operated onschedule, within budget, and in a safe and envi-ronmentally responsible manner.

Our work continues to produce many scientificand technological breakthroughs that lead tonew technologies, markets, and businesses forthe nation.

To all those who have contributed so generouslyof their time and talent, thanks and congratula-tions for a job well done.


Xii Sandia National Laboratories/LDRD FY 1998 Annual Report


Laboratory Directed Research andDevelopment Program Overview

C. E. Meyers

FY 1998Performance

Refereed publications 407

Other publications 223

Patent disclosures 79

Patent applications 48

Patents 7

Copyrights 12

FY 1998Selected Statistics

Full-time staff 278

Smallest project $ 9K

Average project $ 322K

Average project (FTE) 1.21

Largest project $ 4.1M

1ST-year projects 116

2ND-year projects 82

3RD-year projects 32

“Almost every laboratory has foundthat the most important innovation

often comes from the scientists’independent ideas or actions.”The Packard Panel, May 1983,

Federal Laboratory Review Panel:Report of the

White House Science CouncilOffice of Science and Technology Policy

Strategy

Sandia’s value as a nationalresource is our world-class science,technology, and engineering. Thesecapabilities must remain on the cuttingedge because the safety, security, andreliability of U.S. nuclear weaponsdepend directly on them. Under theguidance of Sandia’s LaboratoryDirector and with the DOE’s concur-rence, the Laboratory DirectedResearch and Development (LDRD)Program provides the flexibility toinvest in long-term, high-risk, andpotentially high-payoff researchactivities that stretch Sandia’s scienceand technology capabilities.

LDRD supports DOE’s missionsthrough Sandia’s four primary strategicobjectives: nuclear weapons, nonprolif-eration and materialscontrol, energy and criticalinfrastructure, andemerging national securitythreats. To meet theseobjectives, LDRD promotescreative and innovativeresearch and developmentby funding initiatives thatare inspired by technologyneeds, often high risk, andthat attract exceptionalresearch talent acrossdisciplines.

Authorized by federal law andimplemented under DOE Order 413.2,LDRD is Sandia’s sole source ofdiscretionary research funds. LDRD isfunded by an assessment on all costedwork at Sandia. Atomic energy defenseactivities are supported directly by 67percent of LDRD projects, althoughatomic-energy defense activitiesprovide only 48 percent of LDRDannual funding. More than 90 percentof LDRD projects provide benefits inbasic and applied research to nationalsecurity needs.

In FY 1998, LDRD provided $76.5million to fund 230 projects (selectedfrom 866 submitted). The Sandia LDRDProgram was divided into four princi-pal elements: Core Science andTechnology Competencies, Systemsand Technology Solutions, NationalGrand Challenges, and Initiatives.Principal elements were furthersubdivided into areas as follows: CoreScience and Technology Competen-cies (Materials Science and Technol-ogy, Computer Sciences, Electronicsand Photonics, and PhenomenologicalModeling and Engineering Simulation),Systems and Technology Solutions(Manufacturing Science and Technol-ogy, Life-Cycle Systems Engineering,

Completed milestonesfocus project performance on

negotiated metrics.

159 (69%)

36 (15%)

20 (9%)

3 (1%)9 (4%) 3 (2%)

Percentage Milestones Completed100-90% 89-80% 79-70% 69-60% 59-50% 49-0%

FY 1998Funding levels

(MIL $)

2 Sandia National Laboratories/LDRD FY 1998 Annual Report

Information Systems, Precision Sensingand Analysis, Environmental Sciences,and Risk and Reliability), NationalGrand Challenges, and Initiatives.Investment areas are profiled at thebeginning of each section. Each areafunded projects that strengthenedSandia’s core science and technologybase and focused on future DOE andnational needs. The projects permittedSandia staff to explore innovativescientific and technological opportuni-ties that hold high potential for payoffin future applications.

Additional Reading

A comprehensive discussion ofDOE and Sandia’s LDRD Programmanagement and funding sources maybe found in the “Annual Report toCongress on the DOE LaboratoryDirected Research and DevelopmentProgram, FY 1998 LDRD,” datedFebruary 1999, and the “SandiaNational Laboratories FY 1999–2004Institutional Plan,” dated December1998.

Achievements

Outcomes are the best measure ofachievement for LDRD-funded work.The ultimate measure of success iscustomer satisfaction with the product.

The achievements described hereresult from LDRD projects completedduring FY 1998 and/or projects thathad a major impact on one or more ofthe Laboratories or DOE’s missionareas during the year.

Nuclear Weapons Core StockpileStewardship Programs

The United States faces twocritical issues that are the focus ofSandia’s efforts in nuclear weaponsstockpile stewardship. We mustmaintain confidence in a continuouslyaging stockpile, and we must reduceand manage the vulnerability of asmaller stockpile to common modefailures. Moreover, we must resolveboth issues without underground nuclear testing.

Ceramic Process Selected asBaseline for Neutron-GeneratorProduction

In FY 1996, an LDRD projectwas initiated to synthesize complexoxide ceramic materials by a new, morecontrolled process. The focus was onthe preparation of a niobium-dopedlead zirconate titanate (PZT) becauseof its wide application in neutron-generator power supplies. The LDRDproject ended successfully lastSeptember, and subsequent improve-ments funded by Defense Programshave recently led to selection of thisprocess as a baseline for production ofPZT for neutron generators. Additionaldevelopment work to scale the Sandiaprocess up to the volume required tomeet future production needs is underway, with the delivery of the first WarReserve (WR)-qualified materialscheduled for late FY 2002.

100-Year-Life-Cycle Performance andModeling

The nuclear weapons stockpilestewardship program requires that thesystems and processes that undertakethe examination, possible remanufac-ture, and periodic testing of systemsand components continually meetstringent cost and performancestandards. As the stockpile movesbeyond its initial design life, it isbecoming increasingly important thatnew technology be developed toevaluate performance of the overallweapons complex. Sandia, in collabora-

Schematic of an explosively driven neutrongenerator showing the PZT power supply.

A majority of projects havedual-use applications.

Dual-Use186(81%)

Non-Defense18(8%)

Defense26(11%)

Goals and hypothesis status reveals thedynamics of research as each project unfolds.

Goals met

Goalssubstantially met

Goalspartially met

Goalssubstantially

motified

Goals not met

103 (45%)

98 (43%)

26 (11%)

3 (1%)

0 (0%)


ration with MIT and other institutions,is working on an LDRD project todevelop extended life-cycle enterprisesimulation techniques. These tech-niques are using broad approachesthat look at analyzing and understand-ing the full system capability andperformance.

Nuclear Weapons System Compo-nents Science and Technology

Chem-Lab-on-a-Chip

Ultimately, the safety and reliability ofevery nuclear weapon in the stockpiledirectly reflect the level of perfectionwith which we discharge our compo-nent engineering responsibilities.

Sandia is directing its integratedcapabilities in component sciencetoward pioneering developments inadvanced miniaturization technolo-gies. A differentiating capability is ourexpertise in the small, highly inte-grated, low-power, high-functionalitydevices known as integratedmicrosystems. Created through inte-grated circuit fabrication technology,these devices combine diversefunctions, potentially ranging fromprocessing electronics and micro-electromechanical systems to fabricat-ing sensors and communicationdevices on a single substrate or in verysmall multichip modules. We areemploying miniature machining,photolithographic semiconductorprocesses, and silicon micromachiningto fabricate research prototypes ofthese advanced components.

Energy and Critical Infrastructure

Explosives-Detection Portal

Sandia’s explosives-detectionportal may help prevent airlinerhijackings and bombings. The portalcan identify persons who haverecently worked with or have beenexposed to any of a wide variety ofexplosives. The portal passes a puff ofair over a person, then collects andanalyzes the air sample. The detectordetermines both the type and quantityof even small quantities of explosivesand displays this information on acomputer screen. The same technol-ogy can be adapted to detect narcoticsand chemical agents or can be used forenvironmental monitoring.

Materials and Process Science

Simulation and Experiment forMaterials Aging and Synthesis

Stockpile stewardship requiresthat potential problems in criticalmaterials be identified well before anysignificant deterioration that mightlead to eventual failure occurs. Thephysical examination of componentsprovides only a limited database andtends to be reactive rather thanproactive. Understanding the funda-mental science underlying the agingphenomenon is therefore a criticalaspect of stewardship. To completesuch simulations requires the increas-ing use of advanced capabilities suchas that available in massively parallelarchitectures. Massively parallelcomputer simulations offer thepromise to predict the aging ofmaterials at levels of detail fromatomistic to bulk levels and to enableoptimal synthesis of new materials.

Sandia LDRD researchers continueto develop parallel computing codesthat efficiently and accurately predictthe chain of states of atoms, identifycavities in polymer samples, andrender planar shear calculations inmetal crystals. These new techniques,when coupled to computationalquantum chemistry methods, enhancethe ability to treat chemical degrada-tion processes occurring in polymers

An artist’s conceptionof Sandia’s“chem-lab-on-a-chip”shows the push-buttoncontrols (top), theencasements forcomputation and powermanagement (middle),and the analysis systemand batteries (bottom).

A very complex example of anintelligent, integrated microsystem isthe “chem-lab-on-a-chip,” whichrequires the integration of micro-electromechanical system actuationdevices for pumping microfluids andsensing chemicals, integrated comple-mentary metal-oxide semiconductorelectronics for interrogating andinterpreting sensors, and communica-

tions using eitherradio frequency orphotonic devicesbased on compoundsemiconductortechnology.

Sandia’s explosives-detection portal.


and in energetic materials, such asadhesion and corrosion. These resultsprovide scientifically groundedapproaches for calibrating the work-horse simulation methods in theweapons program.

New Class of Room-TemperatureGamma-Ray Detectors

Cadmium zinc telluride crystalsare being used in a new class of room-temperature gamma-ray detectors.Sandia produced the first detailedcharacterizations of the properties andperformance of these crystals, leadingto an explanation of their behavior.Previous radiation detectors could beused only after being cooled to liquid-nitrogen temperatures. The newdetectors are smaller and can be leftunattended for much longer periods.

Sandia’s understanding of cad-mium zinc telluride crystals couldimpact the way nuclear materials aremonitored and could accelerate anemerging $1 billion-per-year medicalimaging business. Discover magazinerecognized the Sandia team leader asInnovator of the Year in the Sightcategory.

Biological Microcavity Laser forBlood Sample Analysis in Minutes

Sandia and the National Institutesof Health patented a hand-held devicethat analyzes blood samples inminutes rather than in the currenttime of hours to weeks. The biologicalmicrocavity laser can immediatelydetect sickle-cell anemia and otherblood anemias, and may be able todetect tiny changes in cell structure,such as those caused by the AIDSvirus. The laser can distinguishbetween cancerous and noncancerouscells and should allow observers tomonitor cancer cell growth and death.The device, based on Sandia’s vertical-cavity surface-emitting laser (VCSEL),generates laser light using individualblood cells from a drop of blood in theVCSEL microcavity. The blood cellbecomes a light guide that reflectsmany times through a sample, sodeviations in the image created by theblood particle are magnified, greatly

increasing the chances of errorlessidentification. The device eliminatesthe traditional need to kill or stainblood cells for better visibility. Thebiological microcavity laser mayinfluence health care by combining thelow cost and small size of semiconduc-tors with the high speed and sensitiv-ity of laser microtechnology.

Engineering Sciences

Refrozen-Food Detector

Frozen food that thaws in transitcan now be identified by an inexpen-sive detector placed in the package.Sandia’s patented detector changescolor when the frozen-food tempera-ture rises above freezing.

Wear-Resistant Diamond Coating

Sandia has developed a simple andinexpensive way to relieve internalstresses of noncrystalline diamondfilms, a significant advance to producewear-resistant coating. Crystallinediamond coatings require hightemperatures to deposit properly, andthey have very rough surfaces. Stress-free coatings are deposited at roomtemperature and are extremelysmooth, which will improve protectionand extend lifetimes of tools, autoparts, and plastics (such as those usedin biomedical devices). Sandia hasapplied for a patent.

Microelectronics and PhotonicsSciences

Microelectromechanical Systems

Microsystems have the potentialto miniaturize weapon functions suchas navigation, trajectory sensing,safing, and fusing while increasingreliability and robustness. A Sandiamicroelectromechanical–based 24-bitcountermeshing gear discriminatorhas been built in the MicroelectronicsDevelopment Laboratory. We coupledprototype discriminators with customprocessing and optical devices fromthe Compound Semiconductor

Research Laboratory to demonstrateoptical shuttering and beam steering.

Sandia’s technology for integra-tion of microelectromechanicalsystems and microelectronics hasbeen licensed for commercial produc-tion. This technology transfer isimportant to establishing a commer-cial source for future integratedmicroelectromechanical systemsapplications in navigation, trajectorysensing, and fusing.

Heat-Pipe Substrate to CoolMicroelectronic Devices

Sandia developed a high-perfor-mance metal heat-pipe substrate(approximately 2 inches square) formicroelectronic cooling applications.The design uses embedded microheatpipes to cool components such asmicroprocessors by transferring largeamounts of heat without active fans orpumps. We developed new micro-machining processes for manufactur-ing the device, using photolithographicprocesses to create patterns on thesubstrate and electroplating processesto fill the patterns with metal. Thedevices underwent thermal testing atSandia to characterize their perfor-mance. Sandia is partnering with amicroprocessor manufacturer and isconsidering other applications for thenew technology, such as cooling thecomponents of computers, cellularphones, and radar systems.

Semiconductor Filament Lasers

LDRD researchers are creating anew type of high beam-quality semi-conductor laser that has the potentialto produce over a thousand timesmore power than that available inconventional semiconductor lasers.Miniature, short-pulse, high-energylasers are key to direct optical ignitionof fuels and explosives, active opticalsensors for weapons systems inlimited visibility environments, andmicromachining micron-size featuresover large areas. This work signifi-cantly advances the understanding ofthe properties of lasing materials interms of power, efficiency, reliabilityand other properties, and so breaks


new ground in defining technologiesthat will be usable in environmentswhere there is limited available primepower and where a strong laser linkmay be of high value. This work greatlyexpands the range of possible applica-tions of semiconductor lasers, particu-larly in the core national securitymission.

Computational and InformationSciences

Asteroid Strike Model Using theTeraflops Supercomputer

Using virtual reality techniques,decades of experience in shockphysics, advanced computer pro-grams, and the world’s fastest com-puter, we recently modeled the impactof a 1.4-kilometer asteroid striking theAtlantic Ocean twenty-five miles southof Brooklyn, NY. Sandia’s teraflopssupercomputer, which performs morethan one trillion mathematical opera-tions per second, calculated a three-

dimensional (3-D) moving picture ofthe collision.

The work supports Sandia’s DOEmission to develop computer codesthat can one day model the extremelycomplex physics processes that occurduring the nuclear weapon blast. In theabsence of actual nuclear testing, theDOE and the weapons laboratories aredeveloping increasingly powerfulsupercomputers and computer codesto simulate the complex 3-D physicsinvolved in nuclear weapon perfor-mance and to accurately predict thedegradation of nuclear weapon com-ponents as they age in the stockpile.

David Crawford sits in front of acomputer image generated bySandia’s teraflops supercomputer, whichcan perform more than one trillion operationsper second. This scenario simulates anasteroid 1.4 kilometers in diameter hitting theAtlantic Ocean 25 miles from Brooklyn, NY.The supercomputer is critical in supportingSandia’s stockpile stewardship mission.



Electronics and Photonics

Electronics and Photonics funding solicits research that ensures the supply of Sandia componentssupporting the DOE mission of stockpile stewardship. This area emphasizes concepts that will enable therealization of small, low-power, highly integrated electronics packages.

Electronics and Photonics projects are represented by two categories of effort: (1) silicon-based microdevicesfor defense, energy, and industrial uses, seeking new concepts for microelectronics, photonics,microelectromechanical systems (MEMS), and sensors; and (2) integration solutions suitable for high-yield, high-reliability microsystems, including integrated packages capable of communication, self-authentication, and encryption.

Because of the potential devastation of losing huge amounts of information during a power outage orwhen a computer freezes up, the development of a method to preserve this information could have arevolutionary impact on society, whether in a commercial, scientific, or home environment. Such adevelopment would be especially helpful in defense systems that work in harsh environments, such asthose associated with satellites and nuclear weapons, where a radiation-hardened, low-voltage chip wouldbe invaluable.

Information is lost because electrons, which are not stable, do much of the memory work in electronicdevices. Attempts to create circuits that save the information on a computer screen use high voltages,which quickly wear down computer electronic components, and they are expensive.

In a project titled "A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory," Sandia researcherssought to design, fabricate, characterize, and optimize simple circuits to create a novel, low-power,nonvolatile memory. They were successful in developing techniques that could lead to an inexpensive,low-powered, memory-retaining device that may keep computer data from being lost during a poweroutage. The technique is simple and requires only a few extra processing steps over those currently usedin creating microchips. This R&D 100 award-winning memory-retentive computer chip uses hydrogen ionsas the primary carriers of information.

Sandia and its partner in this project, France Telecom, have applied for a patent on a prototype memory-retention device that is inexpensive, low-powered, and simple to fabricate.

MATERIALS SCIENCE

& TECHNOLOGY

Creating new materials and processes that enhancenational security and benefit industry is the objectiveof the Materials Science and Technology investmentarea. Projects create materials and products that behavepredictably during the fabrication, production, andaging processes. Predictable behavior helps designerschoose materials and processes according to the kindsof stress that products must endure. Products rangefrom mechanical, electronic, optic, chemical, andmagnetic to “smart” devices that operate on atomicand subatomic levels. There are three categories of Materials Science andTechnology projects: (1) understanding the mechanismsof materials aging to ensure the safety and reliabilityof the nuclear weapons stockpile, (2) novel materials-processing methods to manufacture high-performancehardware rapidly, affordably, and in low volume withno defects, and (3) nanotechnology projects applyingengineering at the atomic scale to develop integratedmicrosystems. One such project is working to convert surfaceimpurities from a nuisance to a nanofabrication tool.Common adsorbed atoms acting as “surfactants” canbe used to manipulate and direct thin-film growth. Theaim is to develop a “surfactant toolkit,” a scientifically-based understanding of how foreign atoms modifygrowth of thin films. This will enable us to produce atwill either flat or three-dimensionally nanostructuredfilms on a wide variety of substrates. This project combines Sandia’s special facilities,including the “atom-tracker” scanning-tunnelingmicroscope (AT-STM), low-energy electron microscopy(LEEM), and massively parallel computation (MPC).The project started with model systems, where thereis experience in the absence of surfactants, studyingsurfactant-modified diffusion on and near metal andsemiconductor surfaces, and integrating our real-timeexperimental and advanced computational modeling�� A broad rule of physics is that “function is determin-ed by structure.” Microscopic measurements from thisstudy indicated the range of potential interactions ofsurface contaminants, and computational techniqueswere developed to analyze metal-on-metal atomic-levelgrowth. These conclusions will establish a model forthinking more generally about surfactant-assistedtransport near defects.





3502.040

Photonic BandgapStructures as a Gateway toNanophotonics

S. Y. Lin, J. R. Wendt, S. R. Kurtz, G. A.Vawter, E. D. Jones, I. J. Fritz, J. F. Klem,B. E. Hammons, P. L. Gourley, S. K. Lyo

The goal of this project is toexplore the fundamental physics of anew class of photonic materials—photonic bandgap (PBG) structures—and to exploit its unique properties forthe design and implementation ofphotonic devices on a nanometer-lengthscale for the control and confinement oflight. The low-loss, highly reflective, andquantum interference nature of a PBGmaterial makes it one of the mostpromising candidates for realizing anextremely high-Q resonant cavity,> 100,000, for optoelectronic applica-tions and for the exploration of novelphotonic physics, such as photoniclocalization, tunneling, and modificationof spontaneous emission rate. Moreover,the PBG concept affords us a newopportunity to design and tailor photo-nic properties in very much the sameway we manipulate, or bandgap-engineer, electronic properties throughmodern epitaxy.

(1) Three-dimensional (3-D)silicon (Si) photonic crystal. Sandiacreated the first-ever Si 3-D photoniccrystal yielding a photonic stop bandat infrared (IR) wavelengths. Weconstructed the crystal in a layer-by-layer fashion from Si usingmicroelectromechanical systems(MEMS) technology. At a thicknessequal to only one wavelength of light,3-D crystal rejects 98% of incidentlight. Such performance is ten timesmore effective than the 1-D distributed-feedback mirrors (distributed Braggreflectors [DBRs]) widely used invertical-cavity surface-emitting laser(VCSEL) technology. Indeed, a 3-Dcrystal is equivalent to a 3-D DBR thatcontrols and manipulates light in allthree dimensions. Our experimentalrealization of a Si–based 3-D photoniccrystal opens a door for Si photonic

crystal devices that is suitable forlarge-scale integration. Due to its largephotonic bandgap, a 3-D photoniccrystal can be used as a bandpassfilter integratable, for example, to a Siwaveguide or a photodetector. Bycreating a single-mode 3-D defectcavity, a narrowband bandpass filterwith an adjustable bandwidth isreadily available. Furthermore, with anattenuation constant of 12 dB per unitcell, the 3-D structure is capable ofproducing a high-quality resonantcavity with a quality factor (Q)exceeding 10,000 and confining light toa fraction of a wavelength. Finally, a3-D photonic crystal may be utilized tomodify and/or suppress the intrinsicthermal emission of a hot object. It willfind important applications in the fieldof IR emissivity engineering andthermal signature recognition.

(2) Three-dimensional (3-D)single-mode resonant cavity. Wesuccessfully fabricated a 3-D PBG-resonant cavity that is single-mode.This is the smallest 3-D Si Ir (iridium)cavity ever achieved. Combining sucha small defect volume with high-Qcavity would enable the realization oftruly novel photonic devices such asthresholdless semiconductors andsingle-mode LEDs. A rather excitingapplication of this type of cavity is inthe development of efficient LEDs fromthe indirect bandgap Si material. Weformed the defect by removing asection of the rods at the fourth layerof the 3-D structure. The defect volumeis about 0.2 wavelength cubic, andcavity modal volume is estimated to beone wavelength cubic. A transmissionspectrum taken from the cavity sampleshows that, indeed, at a properpolarization (transverse electric), wecan observe a string resonant trans-mission within the bandgap.

(3) Experimental demonstration ofguiding and bending of electromagnetic(EM) waves in a photonic crystal. Theefficient guiding and interconnectionof light on a chip is important fortelecommunication and opticalcomputing applications. Conventionaldielectric waveguides can support

guided modes along straight lines withhigh efficiency, yet are restricted byradiation loss to a moderate bendingradius. A recent theoretical investiga-tion suggests that photonic crystalshold the key for overcoming thisproblem.

A linear defect in a photoniccrystal can give rise to a band ofdefect states within the gap and act asa waveguide. Light in the photoniccrystal is confined to and guided alongthe 1-D channel because the gapforbids light from escaping into thebulk crystal. A waveguide bend canthen steer light around a sharp 90-degree corner. A simple scatteringtheory predicts the existence ofreflection nodes where 100% transmis-sion efficiency can be achievedthrough the bend. We demonstratedwaveguiding of EM waves by a PBGline defect and, more importantly,observed near-perfect transmission ofEM waves around a sharp corner in aphotonic crystal. Bending radii weremade smaller than one wavelength. Weobserved an overall high transmission,> 85%, over the entire bandgap regime.More importantly, at two distinctfrequencies, we observed 100%transmission. Light at such frequenciestravels freely inside the photoniccrystal. Such a lossless bending of lightwould have important application inthe field of optical interconnect.

Publications

Refereed

Lin, S. Y., J. G. Fleming, D. L.Hetherington, B. K. Smith, R. Biswas, K.M. Ho, M. M. Sigalas, W. Zubrzycki, S.R. Kurtz, and J. Bur. 1998. “A Three-Dimensional Photonic Crystal Operat-ing at Infrared Wavelengths.” Nature394 (16 July): 251.

Lin, S. Y., J. R. Wendt, G. A. Vawter, J. G.Fleming, D. L. Hetherington, B. K.Smith, W. Zubrzycki, K. C. Chow, S. R.Kurtz, P. R. Villeneuve, J. D.Joannopoulos, R. Biswas, K. M. Ho, andM. M. Sigalas. 1998. “Applications ofPhotonic Crystals in Optoelectronics.”Proc. SPIE 3419 (9 July): 268.


3502.030

Catalytic Membrane Sensors

T. J. Boyle, R. C. Hughes, C. J. Brinker, A.G. Sault, T. J. Gardner

The goal of this project is todevelop a catalytic membrane–basedsensor (CMS) with enhanced sensitivityand specificity by modifying a Sandia-developed palladium/nickel (Pd/Ni)–based hydrogen sensor. We accom-plished this through overlayers ofsize-selective gas-separation membranesand an ion-exchangeable titanatecatalyst. This report describes in fulldetail the synthesis and processing ofthe various overlayers and their effecton the sensor. We designed and synthe-sized the basic component. Because ofthe low temperature required to main-tain the sensor, we could not determinea suitable catalyst. We began testing newsensors to obtain higher operatingtemperatures.

We demonstrated the feasibilityof synthesizing a CMS component. Thisinvolved the development of a processfor coating the sensor, synthesis andcharacterization of the ion-exchangedcatalyst precursor (and alternatives),and a process for deposition of thefinal layer.

Testing the completed CMSdevice was not feasible for tworeasons: (1) the sensor platform couldnot withstand the high temperaturesrequired to utilize the catalyst effi-ciently, and (2) the operating tempera-ture of the catalyst could not belowered sufficiently to maintain ausable sensor platform. We wereinvestigating alternative platforms atthe end of the project.

We produced several newconcepts and ideas that will prove tobe very beneficial for other areas ofresearch. (1) The most promisingconcept was the use of sol-gel coatingsas a protective coating against thepoisoning of the sensor surface. We

investigated several sol-gel coatings aspoison-control agents, and eachappeared to prevent poisoning of thesurface from H2S. (2) The coatedwafers also displayed an affinity fordetermining the quantity of O2 in thepresence of H2 and could potentially beused as an explosive atmospheresensor. (3) We investigated the use ofzirconium (Zr)–based ion-exchangedcatalyst in place of the standardtitanium-rhodium (Ti-Rh) catalyst;however, due to the low Rh-loadingafter ion-exchange, we did not pursuethese precursors for further develop-ment. (4) We also synthesized novelRhTi6 and ThZr6 double alkoxides thatomit the ion-exchange step. Unfortu-nately, the utility of these catalysts asthin films is still ambiguous since thesmall amount of catalyst led to a smallamount of converted material.

We filed a patent application onthe basic CMS component and thepoison protection ability of the A2**coating.

Publications

Refereed

Boyle, T. J., T. J. Gardner, R. C. Hughes,C. J. Brinker, and A. G. Sault. 1998.“Catalytic Membrane Sensors: A Thin-Film–Modified H2 Resistive Sensor forMultimolecular Detection.” Comts. onInorg. Chem., accepted.

Gardner, T. J., L. I. McLaughlin, L. R.Evans, and A. K. Datye. 1998. “Prepara-tion and Evaluation of Novel HydrousMetal Oxide (HMO)-Supported NobleMetal Catalysts.” Studies in Surf. Sci.and Catalysis 118: 245.

Hughes, R. C., S. V. Patel, M. W. Jenkins,T. J. Boyle, T. J. Gardner, and C. J.Brinker. 1998. “Thin-Film PorousMembranes Based on Sol-Gel Chemis-try for Catalytic Sensors.” Tech. Digestof the 7th Internat. Mtg. on Chem. Sensors(Beijing, China, 27–30 July): 41.

3502.050

Wide-Bandgap CompoundSemiconductors to EnableNovel SemiconductorDevices

M. H. Crawford, A. F. Wright, W. W.Chow, S. R. Lee, E. D. Jones, J. Han

This project is an interdisciplinaryinvestigation into the growth andphysical properties of wide-bandgapcompound semiconductors for thepurpose of enabling both optoelectronicand microelectronic device develop-ment. The AlGaInN (aluminum galliumindium nitride) material system iswidely considered to be essential to thedevelopment of a wide array of ultravio-let (UV) and blue optical devices as wellas high-temperature microelectronics. Acritical limiting factor in the demonstra-tion of advanced III–N–based devices isthe lack of an in-depth understanding ofthe physics and chemistry that governthe unique properties of these materials.Sandia’s work focuses on the investiga-tion of the physical properties of theAlGaInN material system. Analyticalinvestigations include calculations todetermine bandstructure and thedevelopment of a model for optical gainand lasing, which will include an exacttreatment of coulomb effects. We willperform density-functional calculationsto evaluate defect levels associated withextended defects (e.g., edge disloca-tions) in GaN. We will perform steady-state and time-resolved luminescence toevaluate the dominant recombinationmechanisms in these materials. We willalso perform magnetoluminescenceexperiments to determine energydispersion and effective masses, andcompare these results directly withbandstructure calculations. A finalaspect of our project is an evaluation ofhow various processing techniques that


are relevant for device fabrication, suchas post-growth annealing, reactive ionetching, and implantation, affect theoptical and electronic properties of theIII–N materials.

We made significant advances intheoretical modeling of Group-III–Nmaterials. We developed a microscopiclaser theory for treating bandstructureand many-body coulomb effects inGroup-III nitride quantum-well (QW)lasers. We have since furthered thiseffort by studying the contributions ofthese many-body effects to the shapeand carrier-density dependence of thegain spectrum. We gained predictionsfor laser behavior of various InGaN QWstructures and under different experi-mental conditions. We used the theorysuccessfully to analyze experimentalresults. Also, we used these calcula-tions to predict the gain characteris-tics of GaN/AlGaN QW structures. Ourefforts also included a theoreticalstudy of extended defects in Group-III–N materials. We performed density-functional calculations to determinewhether there are defect levelsassociated with the most commontype of dislocation (edge-type) inaluminum nitride (AlN) and galliumnitride (GaN). We found that theseextended defects do indeed introducedefect levels into the gap. Our resultsalso indicate that the exact defectlevels depend on the atomic structureat the core of the dislocation, which, inturn, depends on the backgrounddoping level and on the growthconditions. We predict that edgedislocations can become charged inthe presence of a background concen-tration of n-type dopants and expectapproximately 1.3 electrons per defectsite along the dislocation line inmoderately doped GaN. In the area ofexperimental studies, we performedmagnetoluminescence experiments to

determine the exciton binding energyand reduced mass in GaN thin films.These experiments were performed atthe National High Magnetic FieldFacility at Los Alamos and employedfields up to 60 Tesla. While we ex-pected to see a shift in the photolumi-nescence (PL) resonance as a functionof applied field, no such shift was seen.As yet, we do not understand ourresults and have not determined theexciton binding energy and reducedmass in our materials. We expandedtime-resolved PL experiments toinclude GaN/AlGaN QW structures,which are ideal for UV light-emittingdiodes (LEDs). We grew varioussamples with different well widths andwith or without silicon (Si) doping inthe active region. Our studies showedthat for all samples, the measured PLdecay time decreased strongly withincreasing sample temperature (from10°–300°K), suggesting thatnonradiative recombination is domi-nating in these samples. Also, wefound increased decay times (> 1 ns) at10°K for wider QWs (> 2 nm), which webelieve is due to electron-hole spatialseparation resulting from internalpiezoelectric fields.

Publications

Refereed

Chow, W. W., H. Amano, J. Han, and T.Takeuchi. 1998. “Theoretical Limit tothe Laser Threshold Current Density inan InGaN Quantum-Well Laser.” Appl.Phys. Lett., submitted.

Chow, W. W., K. C. Zeng, R. Mair, J. Y.Lin, and H. X. Jiang. 1998. “Carrier-Population Dynamics in Group-IIINitride Quantum-Well Laser Struc-tures.” 1998 OSA Tech. Digest Series 6(Conference on Lasers andElectrooptics, San Francisco, CA, 3–8May): 282–283.

Chow, W. W., M. H. Crawford, A. Girndt,and S. W. Koch. 1998. “ThresholdConditions for an Ultraviolet Wave-length GaN Quantum-Well Laser.” IEEEJ. Selected Topics in Quantum Electron.4: 314–319.

Kim, H. S., J. Y. Lin, H. X. Jiang, W. W.Chow, A. Botchkarev, and H. Morkoc.1998. “Piezoelectric Effects on theOptical Properties of GaN/AlGaNMultiple Quantum Wells.” Appl. Phys.Lett., submitted.

Wright, A. F. 1998. “TheoreticalInvestigation of an Edge Dislocation inAlN.” Paper presented to the 1998March Meeting of the AmericanPhysical Society, Los Angeles, CA, 16–20 March.

Wright, A. F. 1998. “TheoreticalInvestigation of Edge Dislocations inAlN.” Paper presented to the FourCorners American Physical SocietyMeeting, Albuquerque, NM, 3–4 April.

Wright, A. F. 1998. “TheoreticalInvestigation of Edge Dislocations inGaN.” Paper presented to the 40th

Electronic Materials Conference,Charlottesville, VA, 24–26 June.

Wright, A. F., and J. Furthmiller. 1998.“Theoretical Investigation of EdgeDislocations in AlN.” Appl. Phys. Lett.72: 3467.

Zeng, K. C., R. Mair, J. Y. Lin, H. X.Jiang, W. W. Chow, A. Botchkarev, andH. Morkoc. 1998. “Plasma Heating inHighly Excited GaN/AlGaN MultipleQuantum Wells.” Appl. Phys. Lett.,accepted.


3502.080

Ultra-Hard MultilayerCoatings

T. A. Friedmann, J. A. Knapp, D. M.Follstaedt, M. T. Dugger, N. A. Missert, D.L. Medlin, P. N. Provencio, K. F. McCarty,D. C. Chrzan

Sandia is exploring the productionof ceramic multilayer structures that arepotentially harder than any natural orartificial material. Diamond and cubicboron nitride (cBN) are the two hardestsubstances known to man. Numerousproven technologies rely on the superiormechanical properties of these materi-als. The question arises: Is it possible tomanufacture a material that is harderthan diamond? In theory, the answer isyes. Experiments indicate that properlygrown multilayer coatings of twomaterials are harder than either of thematerials making up the individuallayers. The increase in hardness is duemainly to the resistance of dislocationflow across the interfaces betweenphases of different elasticity. Thisexperimental fact leads to the possibilitythat a new class of ultra-hard materi-als—harder than diamond—can bemade by growing the appropriatemultilayer film. We will establish thestate-of-the-art in ultra-hard multilayersby synergistically merging Sandia’scapabilities. This work is a combinationof growth, analysis, and theoreticalmodeling capabilities at Sandia thatcould possibly lead to a revolutionaryjump in both materials understandingand performance—a material harderthan diamond.

We developed a new multilayer a-tC (amorphous tetrahedral carbon)material that is thick, stress-free,adherent, low friction, and withhardness and stiffness near that ofdiamond. We deposited the new a-tCmaterial by pulsed-laser deposition(PLD) at room temperature and fullystress-relieved it by a short thermalanneal at 600°C. We built up a thickmultilayer by repeated deposition andannealing steps. We measured 88 GPahardness, 1100 GPa Young’s modulus,and 0.1 friction coefficient (under highload). Significantly, these results were

all well within the range reported forcrystalline diamond. However, thismaterial has important advantagesover thin-film diamond; namely, a-tC issmooth, processed at lower tempera-ture, and can be grown on a muchbroader range of substrates. Thisbreakthrough will enable a host ofapplications that we are activelypursuing in microelectromechanicalsystems (MEMs), sensors, LIGA (anacronym for the German words forlithography, electroforming, andmolding), etc. In addition, we dramati-cally improved our cBN films grown byion-assisted PLD (or IAPLD). Wecombined x-ray reflectivity, Fouriertransform infrared (FTIR), and trans-mission electron microscopy (TEM)characterization to optimize the IAPLDprocess to obtain films that have thebulk density of cBN, a columnar cBNgrain structure with greatly reducedhBN inclusions, and smooth surfaces.Thus, we are now ready to deposit byPLD multilayers of (arguably) the twohardest substances known to man—stress-relieved a-tC and cBN, due tobreakthroughs directly resulting fromthis project. Additional highlightsinclude development of an electroncyclotron resonance (ECR) ion-assisted sputtering process for B4Cthat is compatible with our improvedcBN deposition process developedearlier. We are using this process tosynthesize cBN/B4C multilayers. Also,we vastly improved our finite-elementmodeling (FEM) techniques to extractyield, elastic stresses, and hardnessfrom nanoindentation curves. Finally,we made progress in modeling disloca-tion sources and the role they play inpileups as a step toward modelingdislocations in multilayers.

Publications

Refereed

Cardinale, G. F., D. G. Howitt, K. F.McCarty, D. L. Medlin, P. B. Mirkarimi,and N. R. Moody. 1996. “Analysis ofResidual Stress in Cubic Boron NitrideThin Films Using MicromachinedCantilever Beams.” Diamond and Relat.Mater. 5 (November): 1295–1302.

Cardinale, G. F., D. L. Medlin, P. B.Mirkarimi, K. F. McCarty, and D. G.Howitt. 1997. “Orientation-Dependenceof Elastic Strain Energy in Hexagonaland Cubic Boron Nitride Layers inEnergetically Deposited BN Films.” J.Vac. Sci. Technol. A-Rapid Commun. 15(15 January): 196–200.

Dinardo, N. J., T. W. Mercer, L. J.Martinez-Miranda, M. P. Siegal, T. A.Friedmann, and J. P. Sullivan. 1998.“Analysis and Modification of Amor-phous and Partially Crystalline ThinFilms.” Proc. Mat. Res. Soc. 498 (In-vited) (May) (Boston, MA, 1–5 Decem-ber): 67.

Follstaedt, D. M., J. A. Knapp, S. M.Meyers, M. T. Dugger, T. A. Friedmann,J. P. Sullivan, T. Christenson, O. R.Monteiro, J. W. Ager, and I. G. Brown.1997. “Energetic Particle Synthesis ofMetastable Layers for SuperiorMechanical Properties.” Paper pre-sented to the Fall Meeting of theMaterials Research Society (Invited),Boston, MA, 1–5 December.

Friedmann, T. A., J. P. Sullivan, D. R.Tallant, N. A. Missert, J. A. Knapp, D. MFollstaedt, and D. L. Medlin. 1998.“Pulsed-Laser Deposition of Amor-phous-Tetrahedral Carbon Film.” Paperpresented to the Gordon ResearchConference on Laser Interactions withMaterials, Andover, NH, 7–13 June.

Friedmann, T. A., J. P. Sullivan, J. A.Knapp, D. R. Tallant, D. M. Follstaedt,D. L. Medlin, and P. B. Mirkarimi. 1997.“Thick Stress-Free Amorphous-Tetrahedral Carbon Films with Hard-ness Near that of Diamond.” Appl.Phys. Lett. 71 (29 December): 3820–3822.

Friedmann, T. A., J. P. Sullivan, N. A.Missert, D. R. Tallant, J. A. Knapp, D.M. Follstaedt, A. J. Magerkurth, and D.L. Medlin. 1998. “Residual Stress andHardness in Amorphous Carbon FilmsGrown by Pulsed-Laser Ablation.”Paper presented to the 1998 FallMeeting of the Materials ResearchSociety (Invited), Boston, MA, 30November–4 December.

Friedmann, T. A., J. P. Sullivan, N. A.Missert, D. R. Tallant, J. A. Knapp, D.M. Follstaedt, M. P. Siegal, D. L. Medlin,and K. F. McCarty. 1997. “Growth


Properties and Annealing of Amor-phous Carbon Films.” Paper presentedto the Fall Meeting of the MaterialsResearch Society (Invited), Boston,MA, 1–5 December.

Friedmann, T. A., K. F. McCarty, J. C.Barbour, M. P. Siegal, and D. C. Dibble.1996. “Thermal Stability of AmorphousCarbon Films Grown by Pulsed-LaserDeposition.” Appl. Phys. Lett. 68 (18March): 1643–1645.

Friedmann, T. A., N. A. Missert, K. F.McCarty, D. L. Medlin, P. B. Mirkarimi,and P. N. Provencio. 1998. “Ion-Assisted Pulsed-Laser Deposition ofCubic Boron Nitride.” Paper presentedto the International Conference onMetallurgical Thin Films and Coatings(Invited), San Diego, CA, 27 April–1May.

Knapp, J. A., D. M. Follstaedt, and T. A.Friedmann. 1998. “Finite-ElementModeling of Nanoindentation forEvaluating Mechanical Properties ofThin Layers.” Paper presented to theSpring Meeting of the MaterialsResearch Society, San Francisco, CA,3–7 April.

Knapp, J. A., D. M. Follstaedt, S. M.Myers, J. C. Barbour, and T. A.Friedmann. 1998. “Finite-ElementModeling of Nanoindentation.” J. Appl.Phys., accepted.

Knapp, J. A., D. M. Follstaedt, S. M.Myers, J. C. Barbour, T. A. Friedmann,J. W. Ager, O. R. Monteiro, and I. G.Brown. 1998. “Finite-Element Modelingof Nanoindentation for EvaluatingMechanical Properties of MEMSMaterials.” Surf. & Coatings Technol.104 (May): 268–275.

Knapp, J. A., D. M. Follstaedt, T. A.Friedmann, A. J. Magerkurth, S. W.Clark, O. R. Monteiro, J. W. Ager, I. G.Brown, B. N. Lucas, and W. C. Oliver.1997. “Finite-Element Modeling ofNanoindentation for EvaluatingMechanical Properties of Thin Dia-mond-Like Carbon Layers.” Paperpresented to the Fall Meeting of theMaterials Research Society, Boston,MA, 1–5 December.

Knapp, J. A., D. M. Follstaedt, T. A.Friedmann, A. J. Magerkurth, S. W.Clark, O. R. Monteiro (LBNL), J. W.

Ager, III (LBNL), I. G. Brown (LBNL),B. N. Lucas, and W. C. Oliver (NanoInstruments, Inc.). 1998. “Finite-Element Modeling of Nanoindentationfor Evaluating Mechanical Properties ofDiamond-Like Carbon Films.” Appl.Phys. Lett., submitted.

Martinez-Miranda, L. J., J. P. Sullivan, T.A. Friedmann, M. P. Siegal, and N. J.Dinardo. 1997. “Structural Character-ization of the Thermal Evolution ofTetrahedrally Coordinated AmorphousCarbon Films.” Proc. Mat. Res. Soc. 498(May) (Boston, MA, 1–5 December): 55.

McCarty, K. F., and D. L. Medlin. 1997.“How Plastic Deformation Can ProduceTexture in Graphitic Films of BoronNitride, Carbon Nitride, and Carbon.”Diamond and Relat. Mater. 6 (May):1219–1225.

McCarty, K. F., D. L. Medlin, P. B.Mirkarimi, and G. F. Cardinale. 1996.“How Nucleation and Growth Mecha-nisms Control Microstructural Evolu-tion in Cubic Boron Nitride Films.”Paper presented to the MaterialsResearch Society Meeting, Boston, MA,2–6 December.

McCarty, K. F., P. B. Mirkarimi, D. L.Medlin, T. A. Friedmann, and J. C.Barbour. 1996. “On the Low-Tempera-ture Threshold for Cubic Boron NitrideFormation in Energetic Film Deposi-tion.” Diamond and Relat. Mater. 5(December): 1519–1526.

Medlin, D. L., P. B. Mirkarimi, G. F.Cardinale, and K. F. McCarty. 1996.“Microstructural Development inCubic Boron Nitride Thin Films.” Paperpresented to the 43rd National Sympo-sium of the American Vacuum Society(Invited), Philadelphia, PA, 14–18October.

Medlin, D. L., P. B. Mirkarimi, G. F.Cardinale, and K. F. McCarty. 1997.“Microstructure and Texture Develop-ment in Cubic Boron Nitride ThinFilms.” Paper presented to the TMS1997 Meeting, Orlando, FL, 9–13February.

Medlin, D. L., P. B. Mirkarimi, T. A.Friedmann, G. F. Cardinale, and K. F.McCarty. 1998. “Origins of Crystallo-graphic Texture in Cubic Boron Nitride

Thin Films.” Paper presented to theFall Meeting of the Materials ResearchSociety, Boston, MA, 27 November–1December.

Mirkarimi, P. B., D. L. Medlin, K. F.McCarty, D. C. Dibble, W. M. Clift, J. A.Knapp, and J. C. Barbour. 1997. “TheSynthesis, Characterization, andMechanical Properties of Thick,Ultrahard Cubic Boron Nitride FilmsDeposited by Ion-Assisted Sputtering.”J. Appl. Phys. 82 (15 August): 1617–1625.

Mirkarimi, P. B., K. F. McCarty, and D. L.Medlin. 1997. “Review of Advances inCubic Boron Nitride Synthesis.” Mater.Sci. Engin. Reports 21 (15 December):47–100.

Mirkarimi, P. B., K. F. McCarty, D. L.Medlin, N. R. Moody, and D. C. Dibble.1996. “Synthesis and MechanicalCharacterization of Very Hard CubicBN–Based Films Deposited by Ion-Assisted Sputtering.” Paper presentedto the Materials Research SocietyMeeting, Boston, MA, 2–6 December.

Mirkarimi, P. B., K. F. McCarty, G. F.Cardinale, D. L. Medlin, D. K. Ottesen,and H. A. Johnsen. 1998. “SubstrateEffects in Cubic Boron Nitride FilmFormation.” J. Vac. Sci. and Technol. A14 (January–February): 251–255.

Missert, N. A., T. A. Friedmann, J. P.Sullivan, and R. G. Copeland. 1997.“Characterization of Electron-Emissionfrom Planar Amorphous-Carbon Thin-Films Using In Situ Scanning ElectronMicroscopy.” Appl. Phys. Lett. 70 (14April): 1995–1997.

Missert, N. A., T. A. Friedmann, J. P.Sullivan, and R. G. Copeland. 1997.“Evolution of the Electron EmissionCharacteristics from AmorphousCarbon Thin Films Upon Annealing.”Paper presented to the Fall Meeting ofthe Materials Research Society,Boston, MA, 1–5 December.

Missert, N. A., T. A. Friedmann, P. P.Newcomer, P. B. Mirkarimi, K. F.McCarty, and D. L. Medlin. 1996. “X-RayReflectivity Studies of the Density andThickness of BN Thin Films.” Paperpresented to the Materials ResearchSociety Meeting, Boston, MA, 2–6December.


Siegal, M. P., J. C. Barbour, P. N.Provencio, D. R. Tallant, and T. A.Friedman. 1998. “Amorphous-Tetrahe-dral Diamond-Like Carbon LayeredStructures Resulting from Film GrowthEnergetics.” Appl. Phys. Lett. 73 (10August): 759–761.

Sullivan, J. P., T. A. Friedmann, and A.G. Baca. 1997. “Stress Relaxation andThermal Evolution of Film Propertiesin Amorphous Carbon.” J. Elect. Mater.26 (September): 1021–1029.

Sullivan, J. P., T. A. Friedmann, N. A.Missert, P. A. Schultz, M. P. Siegal, andE. B. Stechel. 1998. “The ElectronicTransport Mechanism in AmorphousTetrahedrally-Coordinated CarbonFilms Deduced from CombinedTransport and Stress RelaxationMeasurements.” Proc. 1st Internat.Specialist Mtg. on Amorphous Carbon’97 1 (February) (Cambridge, UK, 31July–1 August): 320.

Sullivan, J. P., T. A. Friedmann, R. G.Dunn, E. B. Stechel, P. A. Schultz, andN. A. Missert. 1997. “The ElectronicTransport Mechanism in AmorphousTetrahedrally Coordinated CarbonFilms.” Proc. Mat. Res. Soc. 498 (May)(Boston, MA, 1–5 December): 97.

Tallant, D. R., T. A. Friedmann, N. A.Missert, M. P. Siegal, and J. P. Sullivan.1997. “Raman Spectroscopy of Amor-phous Carbon.” Proc. Mat. Res. Soc.498 (May) (Boston, MA, 1–5 Decem-ber): 37.

3502.090

Scanning Probe–BasedProcesses for Nanometer-Scale Device Fabrication

T. M. Mayer, B. S. Swartzentruber, S. A.Casalnuovo, A. J. Ricco

Development of nanometer-scaletechnologies requires a novel physicsbase that includes fabrication processes,characterization techniques, andmaterials properties allowing reliableperformance of devices at this verysmall length scale. This project willexpand Sandia’s expertise in scanningprobe–based fabrication and character-ization of nanostructures. Our objectiveis to achieve an order-of-magnitudedecrease in feature size compared toconventional fabrication technology.This order-of-magnitude jump in ourability to make small structures opensnew areas of fundamental physicsresearch on the properties ofmesoscopic structures and enables newtypes of electronic and sensing deviceswith enhanced functionality, speed, andreliability. We are exploring approachesto nanostructure fabrication andcharacterization using scanning probe–based scanning-tunneling microscopy(STM) and atomic force microscopy(AFM). We also are developing numeri-cal simulations of localized electric-fieldand emission current to exploremechanisms and characterize limits toprocessing techniques. We will empha-size novel fabrication processes andcharacterization of physical, chemical,and electronic effects in nanostructures.We will integrate critical nanoscalecomponents with conventional teststructures to allow full electricalaccessibility. We will investigatemolecular layer resists based on simpleadsorbed atoms and molecules that canbe patterned by electron-induceddesorption or reaction. We also aredeveloping direct-write fabricationprocesses for nanoscale fabricationusing electric fields and the low-energyelectron flux from an STM to directly

induce deposition processes leading tonanostructure formation. We willperform electrical measurements ofnanometer-scale structures to investigatethe effect of material structure on thesesmall length scales on electronicproperties. We will evaluate novel, high-sensitivity, chemical-sensor prototypesbased on alteration of electrical proper-ties of nanowires by adsorption orabsorption of gases.

We investigated contrastingsurface modification of Au(111) (gold)surfaces in the presence of highelectric fields, characteristic of thefields that exist under a scanningprobe tip. We observed dramaticsurface distortions when a 200 nm tip,biased at -100 V, is brought toward theAu surface, then retracted. Otherexperiments maintain a constant high-field and field-emission current. STMimages, taken after each procedure,show that high electric field causesstep retraction, vacancy islandformation, and disappearance of smallislands beneath the tip. Very highfields result in unstable bump forma-tion beneath the tip. We adapted ournanofabrication simulation code toexplore effects of electric fields,mechanical forces, and emissioncurrent-induced heating on surfacemodification processes in scanningprobes. We showed that for a tungsten(W) tip interacting with a Au surface,surface diffusion of Au atoms in alateral electric-field gradient is respon-sible for formation of nanometer-scalebumps on the Au surface, in agreementwith experiments at high field. Thiswork suggests another practicalmethod for controlled fabrication ofnanoscale structures.

Publications

Refereed

Cabibil, H., J. E. Houston, T. M. Mayer,and G. E. Franklin. 1998. “Electric FieldEffects on the Nanometer-LevelSurface Modification of Au(111)Surfaces.” Proc. Mater. Res. Soc. (SanFrancisco, CA, 15 April).


Mayer, T. M., J. E. Houston, G. E.Franklin, and T. A. Michalske. 1997.“Electric Field and Emission Current-Induced Surface Modification of Au inthe Interfacial Force Microscope.”Paper presented to the AmericanVacuum Society, San Jose, CA, 23October.

Other

Mayer, T. M. 1998. “Making ThingsSmall, Really Small, with the STM.”Presentation to Northern ArizonaUniversity, Flagstaff, AZ, 23 September.

3502.110

Molecular-Scale Lubricantsfor MicromachineApplications

A. R. Burns, T. A. Michalske, T. M.Mayer, J. J. Sniegowski, P. J. McWhorter,M. J. Stevens, S. L. Miller, M. T. Dugger,J. E. Houston

The goal of this work is to developthe physics and chemistry base fordesigning and understanding molecular-scale lubricants for the reduction offriction- and adhesion-induced failure insilicon (Si) micromachines ormicroelectromechanical systems(MEMS). Sandia acquired this newknowledge by tailoring the molecularproperties of lubricants, applying localprobes that can directly monitor theresponse of lubricants in contactconditions, and evaluating the perfor-mance of model lubricants in MEMSdevices.

Model lubricants under investiga-tion are the silane coupling agents thatform monolayer films on native oxide Sisurfaces, which is the substrate inMEMS. These molecules bind via strongsurface bonds and produce a layer ofhydrocarbon or fluorocarbon chainsnormal to the substrate. Tailoring thelubricants entails modifying the chainlength, the chain chemical reactivity (H[hydrogen] or F [fluorine]), and the

density of chain structures. Thusunderstanding the surface chemistry ofsilane-silicon oxide coupling is critical.With proximal probes such as atomicforce microscopy (AFM), interfacialforce microscopy (IFM), and scanningnear-field optical microscopy (SNOM),we examined the frictional and adhesiveproperties of the silane films with veryhigh spatial resolution (< 100 nm) andsensitivity. We treated MEMS structureswith silanes under identical conditionsand examined them for friction andadhesion under operating conditions.Proper assessment of the lubricantsrequires quantitative analysis of MEMSperformance at high speeds and longoperating times. Our proximal probemeasurements and MEMS performanceanalyses form a very important link formolecular dynamics (MD) simulationsthat, in turn, should be able to predictMEMS performance under all conditions.

We examined friction at themolecular level with a novel scanningprobe microscope that observessimultaneously the onset of energydissipation and attractive forces. Wemonitored friction by measuring thedamped vibrational amplitude of anoscillating probe tip, analogous toshear-force feedback commonly usedin SNOMs. We used a mechanicallystable interfacial force sensor tomeasure normal forces at the tipindependently and decoupled it fromthe lateral forces, thus allowing us toobserve friction from the early stagesof the purely attractive regime to thelatter stage of repulsive compression.Measurements on model lubricantsilane monolayers indicated thatfriction dramatically increases with thestrength of attractive interactionsbetween the tip and the monolayers.These interactions resulted in signifi-cant energy losses due to the tensiledeformation of the lubricant chains,collective chain motion, and dissipa-tive bond breaking.

Cross-polymerization in silaneself-assembled monolayers (SAMs)was thought to be an essential ingredi-

ent of their stability. We used MDsimulations to show that cross-polymerization cannot occur due tosteric effects. Thus, to form dense,fully covered monolayers, cross-polymerization must be avoided. Thestructure of the headgroup plays alimiting role in possible monolayerstructures. To satisfy the stericconstraints, the aliphatic tails mustform a herringbone structure.

Silane treatment of MEMSdevices continues to produce mixedresults, although the overall yield andperformance of operating structuresimprove with silane treatment.Fluorinated silanes are more effectivethan protonated silanes. The trend isreversed in scanning probe studieshere and elsewhere. The fundamentalreasons for the latter are not under-stood and require further investiga-tion.

Publications

Refereed

Burns, A. R., J. E. Houston, R. W.Carpick, and T. A. Michalske. 1998.“Acid-Base Interactions at the Molecu-lar Level: Scanning Probe Studies.” J.Adhesion Sci. Technol., submitted.

Burns, A. R., J. E. Houston, R. W.Carpick, and T. A. Michalske. 1998.“Friction and Molecular Deformation inthe Attractive Regime.” Phys. Rev. Lett.,submitted.

Burns, A. R., J. E. Houston, R. W.Carpick, and T. A. Michalske. 1998.“Molecular-Level Friction as Revealedwith Novel Scanning Probe.” Langmuir,submitted.

Kiely, J. D., and J. E. Houston. 1998.“Contact Hysteresis and Friction ofAlkanethiol SAMs on Au.” Langmuir,submitted.

Stevens, M. 1998. “Thoughts on theStructure of Alkylsilane Monolayers.”Langmuir, submitted.


3502.120

Surface-MicromachinedFlexural Plate-Wave DeviceIntegrated on Silicon

B. A. Tuttle, J. H. Smith, D. B. Dimos, W.K. Schubert, J. A. Ruffner

Small, reliable chemical sensorsare needed for a wide range of applica-tions, such as weapons state-of-healthmonitoring, nonproliferation activities,and manufacturing emission monitoring.Advantages of a flexural plate-wave(FPW) architecture for these sensorsinclude improved sensitivity, reductionin operating frequency to be compatiblewith standard digital microelectronics,and sensing in liquid media. Fabricationof these miniaturized, high-reliabilitydevices requires successful executionand integration of three technologies:acoustic sensor design, silicon (Si)surface micromachining, and high-quality piezoelectric thin-film deposition.Sandia determined the effects ofdeposition parameters in obtainingreasonable piezoelectric output fromaluminum nitride (AlN) films anddeveloped a novel procedure forintegrating lead zirconate titanate (PZT)thin films with silicon nitride (SiN)-membraned devices.

We fabricated both surfaceacoustic-wave (SAW) and FPW PZTpiezoelectric thin-film devices. Wefabricated PZT SAW devices on bothLaAlO3 and Si substrates. These second-generation PZT SAW designs eliminatedthe conducting ground-plane electrode,which had resulted in low-impedancedevices due to the high dielectricconstant for the PZT films. The LaAlO3

substrates act as an electrically insulat-ing template for growth of highlyoriented PZT films. On the Si substrates,

we used zirconia (ZrO2) as the electri-cally insulating template layer. The PZT/LaAlO3 SAW devices operated atfrequencies ranging from 50 to 175 MHz,depending on the transducer wave-length. Some of the PZT/ZrO2/Si SAWdevices did show acoustic responsesthat were sensitive to absorbed mass onthe surface of the device. However, theresonant frequencies of the devices weremuch higher than expected for thetransducer wavelengths and layerthickness involved, and indeed did notscale with the transducer period. All ofthe Si–based devices had their strongestresponse at around 125 MHz, regardlessof the transducer-defined wavelength(which varied from 120 to 28 microns).This suggests that bulk modes wereexcited at frequencies dependent moreon layer thickness than on transducerwavelength.

We developed device designsand obtained appropriate masks tofabricate bulk-micromachined FPWdevices using PZT films with conduct-ing bottom electrodes. These devicesuse interdigitated transducers (IDTs)with one of the combs of fingersconnected to the ground plane. Sincethe PZT film thickness is much lessthan the finger spacing in the IDTs, theelectric field between the drive fingersand the ground plane is dominant, andthe other set of fingers plays little rolein driving the piezoelectric film.Acoustic wavelengths for the bulk-micromachined FPWs ranged from 246to 320 microns.

Process integration efforts werehighlighted by the development ofseveral new techniques that wereessential to the fabrication of PZT thin-film//SiN microelectromechanicalsystem (MEMS) devices. A criticaldevelopment was the efficient, uniform

adherence of titanium//platinum (Ti//Pt) electrode technology to SiNmembranes through the use of a thin,60 nm, SiO2 sputter-deposited layer.Two other important findings thatallowed PZT//SiN devices to befabricated were mask design/pattern-ing to avoid PZT//SiN contact any-where on the wafer and elimination ofthe use of hexamethyldisilizane(HMDS) adhesive due to its detrimen-tal effect on the underlying Pt metal-lurgy. We used a new technology,termed high-aspect-ratio silicon etch(HARSE) processing, to define sharpmembrane structures in Si for thefabrication of compound clamped–clamped cantilever beam devices. Weimproved project enhancement ofpiezoelectric response by a factor of1000 compared to simple cantileverbeam structures. Finally, we developeda metal-etch procedure for chromium/gold (Cr/Au) electrodes on the PZTdevices because of yield problemswith lift-off patterning of IDTs with theneeded dimensions (lines and spacesof around 10 microns). No deleteriouseffects of the etch process weredetectable on the low-frequencypiezoelectric properties of the PZTfilms, so we used this procedure forsubsequent SAW lots and the bulk-micromachined FPW lot.

We fabricated AlN films that werehighly oriented in terms of bothcrystallographic and c+/c- domainconfigurations. We obtained piezoelec-tric coefficients of 5.4 pM/V from thesehighly oriented films, in reasonableagreement with single-crystal values.We developed a fundamental under-standing of the effect of nanoscaletemplate layers on AlN domainorientation. A thin, approximately 5nm-thick, ruthenium-dioxide (RuO2)


layer will alter domain configurationscompared to Ru layers. Control of thislayer formation results in piezoelectricconstants close to single-crystalvalues. If formation of the nanoscaleinterface layers is not controlled,essentially no macroscopic piezoelec-tric response is obtained.

Publications

Refereed

Clem, P. G., B. A. Tuttle, J. A. Voigt, T. J.Garino, and M. Rodriguez. 1998.“Design of CSD Routes for BaTiO3, PZN/PT, and PZT Thin-Film Devices.” Paperpresented to the 10th InternationalSymposium on Integrated Ferroelec-trics, Monterey, CA, 2 March.

Martin, S. J., M. A. Butler, J. J. Spates,M. A. Mitchell, and W. K. Schubert.1998. “Flexural Plate-Wave ResonatorExcited with Lorentz Forces.” J. Appl.Phys. 83 (5 May): 4589–4601.

Martin, S. J., M. A. Butler, J. J. Spates,M. A. Mitchell, and W. K. Schubert.1998. “Magnetically-Excited FlexuralPlate-Wave Resonator.” IEEE Trans. onUltrasonics, Ferroelect., and Freq.Control Symp. 45 (Los Angeles, CA, 15June): 1381–1387.

Ruffner, J. A., D. Dimos, P. G. Clem, andB. A. Tuttle. 1997. “Effect of DepositionParameters on Piezoelectric Responseof Reactively Sputtered AlN.” Paperpresented to the ASM/ACerS Meeting,Albuquerque, NM, 3 November.

Tuttle, B. A., T. J. Garino, P. G. Clem, J.A. Ruffner, and W. K. Schubert. 1998.“Materials Analysis of Pb(Zr,Ti)O3 Thin-Film//Si-Micromachined Structures.”Paper presented to the MaterialsResearch Society Meeting, Boston, MA,2 December.

3502.140

Smart Interface BondingAlloys (SIBA): Tailoring Thin-Film Mechanical Properties

R. Q. Hwang, S. J. Plimpton, N. D. Shinn,N. R. Moody, J. E. Houston, J. C.Hamilton

Sandia will explore the use of thenewly discovered, strain-stabilized, 2-Dinterfacial alloys as smart interfacebonding alloys (SIBAs). We will usethese materials as templates for theheteroepitaxial growth of metallic thinfilms. SIBAs are formed by two metalliccomponents that mix at an interface torelieve strain and prevent dislocationsfrom forming in subsequent thin-filmgrowth. The composition of the SIBA isdetermined locally by the amount ofstrain, and therefore can react “smartly”to areas of the highest strain to relievedislocations. In this way, we can useSIBA to tailor the dislocation structure ofthin films.

This project will include growth,characterization, and modeling of filmsgrown using SIBA templates. Character-ization will include atomic imaging ofthe dislocations structure, measurementof the mechanical properties of the filmusing interfacial force microscopy (IFM)and the nanoindenter, and measurementof the electronic structure of the SIBAwith synchrotron photoemission. We willalso examine resistance of films tosulfidation and oxidation. We will usethe Paragon parallel processing com-puter to calculate the structure of theSIBA and thin films to develop theability to predict and tailor SIBA andthin-film behavior.

This work will lead to the develop-ment of a new class of thin-film materi-als with properties tailored by varyingthe composition of the SIBA, serving asa buffer layer to relieve the strainbetween the substrate and the thin film.Such films will have improved mechani-cal and corrosion resistance, allowingapplication as protective barriers forweapons applications. They will alsoexhibit enhanced electrical conductivityand reduced electromigration, making

them particularly suitable for applica-tion as interconnects and other elec-tronic needs.

Our accomplishments includethe following:

• Measured IFM indentationcurves for Au(111) (gold) and investi-gated the role of surface steps. Thisresult has proven valuable not only forour SIBA project, but also in develop-ing modeling techniques that can beapplied to other work.

• Developed and debuggedindentation modeling code on theParagon computer. The ability to usethis code to model indentation led tonew insights into the atomisticprocesses governing the onset ofplastic deformation.

• Developed an algorithm forautomated identification of disloca-tions in complex structures.

• Modeled indentation onAu(111) and Au(100). The modeling ofthese two surfaces showed theimportance of the crystal structure indefining mechanical properties. Inparticular, the overall governing natureof (111) slip planes dominates thebehavior of both surfaces in responseto indentation.

• Measured the effect of surfacedefects on the local elastic and plasticproperties of Au(111). In addition, wealso developed new IFM sensors thatexhibit greater reliability and perfor-mance.

• Measured dislocation structureof silver (Ag) film grown on SIBAmaterial.

• Measured stability of SIBAinterface.

Publications

Refereed

Kelchner, C. L., S. J. Plimpton, and J. C.Hamilton. 1998. “Dislocation StructureDuring Indentation of PassivatedAu(111).” Phys. Rev. B, accepted.

Kiely, J. D., R. Q. Hwang, and J. E.Houston. 1998. “The Effect of SurfaceSteps on the Plastic Threshold inNanoindentation.” Phys. Rev. Lett.,accepted.


3502.190

Molecular-to-ContinuumFracture Analysis ofThermoset Polymer/SolidInterfaces

M. S. Kent, M. J. Stevens, E. D. Reedy, Jr.

Sandia is investigating submicrondebonding processes at polymer/solidinterfaces with a combination ofcontinuum stress analysis, moleculardynamics (MD) simulations, and newexperimental approaches. Our objectiveis a validated, molecular-to-continuumfracture theory. On the continuum level,we made considerable headway in aninterfacial fracture mechanics approachfor preexisting macroscopic cracksbetween linear elastic materials. Little isknown, however, about modeling crackson a micron or submicron level, howmicrocracks develop into macroscopiccracks, or about length-scale limitationson the use of a continuum analysis.Furthermore, the effect of interphasestructure and molecular properties onfracture mechanics parameters, neededfor a fundamental understanding offailure criteria, is unknown. On themolecular scale, much is known aboutpolymer dynamics, the origin of vis-coelastic behavior and relaxationphenomena, and the behavior ofpolymers near surfaces. Yet it is notclear how stress concentrations developon a molecular scale in an imperfectthermoset polymer, or how nanoscaleinhomogeneities grow into microcracksunder stress. An understanding of thelink between the molecular and con-tinuum levels is required before the goalof a truly comprehensive model offracture can be approached.

This past year we performed MDsimulations using two-bead chains thatqualitatively reproduce experimentalstress-strain curves in epoxies. Wedetermined distributions of bond lengthsas the system was strained. We deter-mined the structure of epoxy near silicon(Si) surface by neutron reflection (NR)

as a function of stoichiometry, coatingmethod, cure temperature, and afterthermal cycling. We performed NRmeasurements with samples subjected tothree-point bend loading. We developedtwo experimental methods for continu-ously varying interface strength basedon self-assembled monolayers (SAMs).We discovered that adhesive-to-cohesivetransition occurs over a very narrowrange of SAM coverage. We alsodeveloped a novel, sandwiched alumi-num/silicon/epoxy/aluminum, double-cantilevered beam sample to measurethe toughness of a Si/epoxy interfaceunder a mode I-like loading.

The development of MD coarse-grained model epoxy systems encoun-tered several (expected) complica-tions. We determined that even short(five-bead) chains exhibited elasto-meric response unless we included abond-bending potential to stiffen thechain. Networks made of stiff chainshad stress-strain curves of the epoxyform. However, simulations of largersystems showed that the stiff chainstend to become aligned, and voidsform in the liquid. To prevent thisbehavior, we went to two-bead chainsthat do not require the bond-bendingand do not form the liquid-crystalphases. With two-bead chains, we wereable to qualitatively reproduce theexperimental (and continuum mechan-ics [CM]) stress-strain curves. Wecalculated stress-strain curves as afunction of temperature and confirmedthat the trends are the same as CMpredictions.

We characterized the networkstructure in a variety of ways. Wecoded a cluster analysis of the connec-tivity and used it to calculate thecluster size and distribution within thenetwork. For all our networks, weachieved about 95% of possiblecrosslinks. The largest cluster containsabout 90% of the crosslinks with theremaining strands consisting of smallclusters (single chains or a few chainscrosslinked). We are also calculatingthe minimal path in the network from a

bonded site on the top substrate to abonded site on the bottom substrate.We calculated the bond length distri-butions as the system was strained.Somewhat surprisingly, they show thatthe bonds are not stretched signifi-cantly, even though the system issignificantly strained. We devotedfurther work to determining the localstress field in the MD.

We determined the near-surfacestructure of an epoxy film on Si as afunction of stoichiometry, coatingmethod, and cure temperature. In allcases, we found a layer of elevateddensity near the interface (less than503). This effect is most likely due topacking of oligamers next to the hard,smooth surface. In further work, wethermal-cycled samples from 40°C to65°C for 7 months and detected novariation. This is consistent withcontinuum stress analysis, whichindicates that stress acts only on theedges of these samples in this mode ofloading. Therefore, a different way ofapplying a stress must be imple-mented. To that end, we fabricatedreflectivity samples that could beloaded in three-point bend geometry.They consisted of a thin film of epoxybetween two polished Si blocks. Wesuccessfully performed NR experi-ments, and preliminary data suggest avariation in the interface structureafter cycling.

We devoted much work tomeasuring fracture energy as afunction of interface strength. We hadto overcome two difficulties: (1) amethod was needed for varying theinterface strength in a controlled way,and (2) well-defined fracture tests wereneeded that could be performed withSi substrates.

We developed two methods forvarying interface strength, each basedon SAMs: (1) vary time of exposure tocoating solution, and (2) use photoli-thography to vary the ratio of surfacearea that is exposed/unexposed to theSAM solution.


We studied adhesive/cohesivefracture transition as a function ofinterface strength using SAMs and arod/torsion test (nearly pure mode II,ill-defined stress state). We discoveredthat adhesive-to-cohesive transitionoccurs over a very narrow range ofSAM coverage.

We adapted napkin/ring torsiontest to Si substrates (nearly pure modeII, well-defined stress state). We begana study of fracture as a function ofinterface strength with SAMs using thisfracture test.

We developed a novel, sand-wiched aluminum/silicon/epoxy/aluminum, double-cantilevered beamsample to measure the toughness of aSi/epoxy interface under a mode I-likeloading. We performed detailed finite-element analyses to determine thecalibration connecting loading andspecimen geometry to energy releaserate and mode mixity. We obtainedfracture energies for no SAM coverageand for full coverage.

Publications

Refereed

Reedy, E. D. 1998. “Connection Be-tween Interface Corner and InterfacialFracture Analyses of an AdhesivelyBonded Butt Joint.” Internat. J. Solids &Structures, Proc. 22nd Ann. Mtg. AdhesionSoc. (Panama City Beach, FL, 24February 1999), accepted.

Other

Kent, M. S., W. F. McNamara, J.Majewski, and G. S. Smith. 1997.“Stress-Induced Degradation ofInterface Structure in Epoxy Films onSilicon Substrates: An In Situ Study byNeutron Reflection.” Paper presentedto the Materials Research SocietyMeeting, Boston, MA, 1–5 December.

Kent, M. S., W. F. McNamara, L.Domeier, and A. P. Y. Wong. 1998.“Characterization of Epoxy StructureNear a Silicon Surface Using NeutronReflection.” Proc. 21st Ann. Mtg. Adhe-sion Soc. (Savannah, GA, 22–25February): 153.

Kent, M. S., W. F. McNamara, L.Domeier, J. Majewski, G. S. Smith, andS. Satija. 1998. “Structure of an EpoxyNear a Smooth SiO2 Surface.” Paperpresented to the Annual Meeting of theAmerican Physical Society, LosAngeles, CA, March.

Stevens, M. J. 1998. “Adhesive Failurein Thermosetting Polymers.” Paperpresented to the Materials ResearchSociety Meeting, Boston, MA, 30November–4 December.

3502.210

Monolithic Structures forNanoseparation

T. J. Shepodd, M. E. Warren, D. S. Anex,A. Martino

Miniaturization in detection andseparation technologies requires easilybuilt, rugged devices based on materialsthat have well-understood interactionswith analytes at the molecular level. Thegoals of this project are to design suchmaterials for state-of-the-art separationscience, understand their structure/function relationships, and fabricatethem into useful devices. We areutilizing Sandia’s expertise in thesynthesis of microporous and nano-porous materials to develop continuous,high-surface-area polymers as mono-lithic nanoporous supports for ultra-efficient separations. We are evaluatingthese materials using capillary electro-chromatography (CEC) as a test-bed. Wewill quantify the interaction offunctionalized surfaces of these supportswith analytes, propelled by the electroos-motic flow (EOF), in terms of separationefficiency and selectivity. Our goal is toengineer an open and interconnectednetwork where every nanopore func-tions as a CEC column. We will integratethese new solid supports, which are castas fluids and cured to monolithicpolymer structures, into micromachinedgrooves as pre-prototype devices forultra-efficient separations.

Our work thus far has greatlyincreased our understanding of analyte/support interactions as influenced byengineered materials. The monolithshave been spectacularly successful inother micromachine-type devices. Wemade two patent disclosures.

We designed and synthesizedmonolithic polymer supports thatfunction as CEC columns. We demon-strated that these columns supportEOF and showed baseline separationof analytes in simple chromatographyexperiments. We developed efficientsynthetic routes to organic andinorganic monolithic supports. Wediscovered a way to use inverseemulsion polymerization to simulta-neously create the chromatographymedium, the species to support EOF,and the bonds connecting the supportto the substrate (capillaries in thesestudies). Thus, we avoid time-consum-ing and logistically difficult surfacemodification chemistry. They can bedesigned to support positive andnegative EOF, and the EOF directioncan be switched. We synthesized asecond generation of supports forimmediate testing. The second-generation supports are based onphase-separation polymerization anddemonstrated modest separationefficiencies. We also demonstrated thatwe can modify the micro- and macro-structure of the monoliths, as pre-dicted, by varying synthetic param-eters. We incorporated the phase-separation–generated monoliths intodevices powered by EOF. Thesedevices have been spectacularlysuccessful, and we released patentdisclosures covering the devices andtheir compositions.


3502.170

Recognizing Atoms inAtomically EngineeredNanostructures: AnInterdisciplinary Approach

K. M. Horn, J. S. Nelson, G. C. Osbourn,R. M. Biefeld, M. P. Sears, D. R.Jennison, A. M. Bouchard

Scanning-tunneling microscopy(STM) is a powerful tool for bothcharacterizing and manipulating theatomic topographies of surfaces.However, STM has typically been unableto provide unambiguous chemicalrecognition of atomic sites in manytechnologically relevant, but chemicallyheterogeneous, systems. Sandia willdevelop the theoretical and experimen-tal underpinnings necessary to enableunambiguous, computer–based identifi-cation of atomic sites in multivariateSTM imagery, focusing on heteroge-neous III–V semiconductor materials andatomically engineered nanostructures.The project will have several subtasks:(1) We will seek to develop the firstdatabase of multivariate STM spectralfeatures. (2) We will study the effects ofdifferent tip states on the STM spectralfeatures and attempt to establishprocedures for computationally remov-ing or minimizing variable tip effects.(3) We will use pattern recognition ofSTM spectral imagery, based on theresults of tasks 1 and 2, to map out theatomic-scale chemical structure ofselected cleaved (110) III–V surfaces.We will specifically attempt to under-stand the alloy ordering and interfacialstructure of III–V structures of currentprogrammatic interest for infrared (IR)device applications.

Comparison of topographic andconductance–based STM imagesshowed that surface irregularities in atopographic image do not necessarilyindicate the presence of uniqueelectronic structures. Conversely, STMfeatures that appear topographicallysimilar can, in fact, exhibit distinctly

different electronic behavior. The useof multispectral image analysis tech-niques in the reduction of multibiasSTM conductance data provides aquantitative means of examiningatomic surfaces while still maintainingthe rich information content inherentin an imaging technique. The use of acomputed grouping algorithm greatlystreamlines the data-reduction processand provides a rigorous, reproduciblemeans of discriminating features basedon their conductance spectra.

The ideal situation is to analyzedata acquired from a single STM tip.Multibias conductance images mea-sured with different tips and analyzedwith this multivariate classificationtechnique have consistently producedclassed images that discriminatebetween different chemical speciesand even different bonding states ofthe same species. However, the exactshape of the conductance spectradefining a specific surface featurediffers between tips. This is predomi-nantly due to the variability in boththe atom configuration and composi-tion (silicon [Si] and tungsten [W]atoms) on the tip side of the tunnelingjunction. Thus, at present our classedimages discriminate only betweensurface electronic features, but do notidentify them absolutely. We believethat the ability to absolutely identifyatoms based on their conductancespectra can be achieved through strictcontrol or characterization of the STMtip, so that reproducible conductancespectra are measured from surface tosurface. This may require utilizingfield-ion microscopy (FIM) of the tipbefore multibias measurements.However, it may also be possible todevise post-measurement transforma-tions of the measured conductancespectra that will factor out variationsin tip structure. This latter approachholds some promise since such datatransformation techniques are alreadyused in other multivariate classifica-tion analyses, e.g., chemical sensing,where similar problems with variability

of sensor response and uneven signalattenuation are compensated for bysensor recalibration and renormali-zation of sensor response.

Using a single STM tip, weshowed that classed images of simplefeatures in Si(001)-2x1 surfacescorrelate well with obvious featuressuggested by the correspondingtopographic images. The periodicity ofthe 2x1 dimer row structure, A- and B-step edges, kinks in step edges, 2+1vacancies, and c-defects were allresolved in conductance–based imagesof this atomic surface. The classed,conductance–based images alsorevealed surface electronic structuresnot suggested by the topographicimages. Classed images of the B-step inthe Si(001)-2x1 surface indicate thepresence of two electronically distinctrows at the base of the B-step; thesefeatures correlate well with theposition of rebonded atoms proposedin models of the single B-step. Further-more, the termination of the dimertrough of the upper terrace at the B-step exhibited unique conductancecharacteristics while the terminationof the dimer row does not. This mayreflect the presence of exposed,undimerized dangling bonds at thestep edge. This interdisciplinaryapproach to the data analysis ofmultivariate STM data adds significantvalue to the interpretation of theimages of atomic surfaces.

We were unable to exploit thepower of our approach to studycleaved III–V heterostructures asoriginally intended.

Publications

Refereed

Horn, K. M., B. S. Swartzentruber, G. C.Osbourn, A. M. Bouchard, and J. W.Bartholomew. 1998. “ElectronicStructure Classifications Using Scan-ning-Tunneling Microscopy Conduc-tance Imaging.” J. Appl. Phys. 84 (1September): 2487–2496.


3502.220

Fundamental Aspects ofMicromachine Reliability

M. P. De Boer, J. A. Knapp, T. M. Mayer,J. J. Sniegowski, J. M. Redmond

A fundamental basis for designingmicromechanical devices with high-yield, reliable performance and long lifeis lacking. Mechanical design tools formacroscale machines relate reliability toinertial forces. However, the perfor-mance of micron-scale structures of high-aspect ratio is dominated by surfaceforces. The technical goal of this projectis to use experimental reliability resultsobtained directly from micromachinedtest structures to develop and verifymechanics models containing interac-tion terms appropriate to the micron-scale (e.g., capillarity, van der Waalsforces, electrostatics, etc.). Issues to beaddressed include auto-adhesion(stiction), friction, and wear. Beginningwith auto-adhesion, Sandia will designand build microbridge structures withvarying geometry and surface properties(roughness, chemical coatings, etc.). Wewill monitor deformations by interferom-etry in an environmental chamber. Wewill develop finite-element modelsincorporating new surface elements, andverify and refine them by comparingthem against experimental results. Next,we will investigate friction and wearusing smart micromachined structuresthat enable self-diagnosis by electricalmonitoring of capacitance and Q-factorchanges. We will also explore opticaldetection techniques. We will verify and

refine dynamical response modelsincorporating internal friction terms, aswell as damping, using experimentalresults. We will then extract friction dueto energy loss at rubbing surfaces.

This project will develop a newtool set based on an experimental andtheoretical foundation. We will use thetool set to calculate and characterizereliability of micromachines for inte-grated microsystem applications.

We accomplished the following:• Compared the integrity of

various coatings subject to high andlow relative humidity (RH). We foundadhesion to be exponentially depen-dent on RH. This trend was explainedby comparing to models of capillarycondensation. We showed that for asmooth interface, the adhesion shouldbe independent of RH. This agrees wellwith crack healing data for glass,which fractures in an atomicallysmooth fashion, but disagrees with ourdata. However, due to roughness ofour material, the surfaces come intocontact only at asperity tips. Weshowed that a single asperity modelfor adhesion versus RH agrees wellwith our experimental results.

• Applied analytical techniques(e.g., Fourier-transform infrared[FTIR], ellipsometry) to determinewater absorption. Small amounts ofwater seem to adsorb even on nomi-nally hydrophobic molecular coatings.

• Developed a method tomeasure adhesion hysteresis. Wemeasured adhesion hysteresis as afunction of exposure to RH. At RH> 90%, our hydrophobic molecular

coating begins to break down, asevidenced by increasing adhesion.

• Fabricated a device to measurecapacitance of adhered beams. Weachieved the expected measurementresults.

• Invented surface terms thataccount for interactions betweenforces, e.g., van der Waals and electro-static.

• Designed and fabricated a newtest chip with simulated friction teststructures, and corrected designs fromthe first test chip.

• Formulated a comprehensivedynamic model incorporating beamvibrations and frictional effects.

• Tested friction test structuresstatically and showed that they work.We determined the friction coefficientof uncoated beams.

• Tested friction test structuresdynamically and demonstratedhysteretic losses.

Publications

Refereed

De Boer, M. P., J. M. Redmond, and T.A. Michalske. 1998. “A Hinged-Pad TestStructure for Sliding Friction Measure-ment in Micromachining.” Proc. SPIE,Mater. and Device Characterization inMicromachining 3512 (Santa Clara, CA,1 September): 241–250.

De Boer, M. P., P. J. Clews, B. K. Smith,and T. A. Michalske. 1998. “Adhesion ofPolysilicon Beams in ControlledHumidity Ambients.” Proc. Mater. Res.Soc. Symp. 518 (December) (SanFrancisco, CA, April).


3502.240

Atomic-Level Studies ofSurfactant-Directed MaterialsGrowth

P. J. Feibelman, B. S. Swartzentruber, G.L. Kellogg, J. A. Floro, N. C. Bartelt, J. C.Hamilton

Sandia will convert surfaceimpurities from a nuisance to a system-atically applicable nanofabrication tool.Combining Sandia’s special facilities,including the atom-tracker scanning-tunneling microscope (AT-STM), low-energy electron microscopy (LEEM), andmassively parallel computation (MPC),we will learn how common adsorbedatoms (surfactants) can be used tomanipulate and direct thin-film growth.Thus, we will develop a surfactanttoolkit that enables us to produce eitheratomically flat or 3-D nanostructuredsurfaces. We will start with modelsystems, where we have experience inthe absence of surfactants, studyingsurfactant-modified diffusion on andnear metal and semiconductor surfaces,and integrating our real-time experimen-tal and advanced computationalmodeling capabilities. We will use theAT-STM to study hydrogen (H)-assistedsilicon (Si) adatom diffusion on Si(001),LEEM to investigate both H-assisted stepfluctuations on the same surface, andoxygen (O)-assisted island growth onPt(111) (platinum). Via novel surfacestress measurements, we will studygermanium (Ge) segregation versusadsorbate overlayer coverage in Si-Gealloys. We will closely couple theoreticalefforts to our experiments; MPC will beindispensable in developing reliable,atomic-scale, mechanistic models.

High-resolution STM measure-ments of localized strain relief near Geand Si islands on Si(001) showeddebuckling of substrate dimersextending over 3+ lattice sites, indica-tive of the lateral range of the varyingpotential interaction. This has implica-tions for growth of Ge and Si, as

diffusing atoms interact with pre-existing structures. We showed thatmorphological phase transitions,accelerated coarsening, and self-organization among SiGe-strainedislands on Si result from elasticrepulsions between neighboringislands. Our first-principles calcula-tions of Pt transport show faciletransport down A-type island edges onPt(111), and thus that O-induced layer-by-layer epitaxy of Pt(111) cannotresult from reduced downwardtransport barriers, as claimed in theliterature. We vindicated the theorywith the discovery of sample contami-nation by background carbon-monox-ide (CO) in the experiments. Via LEEMwe determined the mechanism andenergetics of Si(001) etching byoxygen. We quantified observations ofO-induced stress relief on Si(001) bymeasuring terrace widths and thevelocity of step retraction. New field-ion microscopy (FIM) measurementsgeneralized the conclusion that Hpromotes hopping and inhibitsexchange diffusion. After LEEMmodifications, we made initial observa-tions of nucleation, growth, andcoarsening of a metal-on-metal system:Pt islands on Pt(111). We developed acomputational technique to analyzesuch observations by solving thediffusion equation subject to boundaryconditions determined by the ob-served configuration of surface steps.Finally, to see how lattice mismatchaffects the structure of growingheteroepitaxial films, we used acombination of 2-D elasticity modelsand first-principles calculation,accounting for the misfit dislocationstructure observed in silver (Ag)monolayers on Pt(111).

Publications

Refereed

Carpinelli, J. M., and B. S.Swartzentruber. 1998. “DetailedEnergetic Interactions of Adsorbed SiDimers on Si(001).” Surf. Sci. 411: L828.

Carpinelli, J. M., and B. S.Swartzentruber. 1998. “Direct Measure-ment of Field Effects on SurfaceDiffusion.” Phys. Rev. B, accepted.

Feibelman, P. J. 1998. “Interlayer Self-Diffusion on Stepped Pt(111).” Phys.Rev. Lett. 81 (6 July): 168–171.

Feibelman, P. J. 1998. “Interpretation ofO Binding-Site Preferences on Close-Packed Group VIII Metal Surfaces.”Phys. Rev. B, accepted.

Feibelman, P. J. 1997. “Nature ofAdatom Bonds to Transition-MetalSurfaces.” Paper presented to theNational American Vacuum SocietySymposium, San Jose, CA, 23 October.

Feibelman, P. J., J. Hafner, and G.Kresse. 1998. “Vibrations of O onStepped Pt(111).” Phys. Rev. B 58 (15July): 2179–2184.

Floro, J. A. 1998. “Accelerating IslandCoarsening During SiGe MBE Measuredby Real-Time Spectroscopic LightScattering.” Paper presented to theSpring 1998 MRS Meeting, San Fran-cisco, CA, April.

Floro, J. A., E. Chason, L. B. Freund, R.D. Twesten, and R. Q. Hwang. 1998.“The Kinetics of Coherent IslandFormation in Si1-xGex/Si (001).” Phys.Rev. B, submitted.

Floro, J. A., E. Chason, M. Sinclair, L. B.Freund, and G. A. Lucadamo. 1998.“Dynamic Self-Organization of StrainedIslands During SiGe Epitaxial Growth.”Appl. Phys. Lett. 73: 951–953.

Floro, J. A., G. A. Lucadamo, E. Chason,L. B. Freund, M. Sinclair, R. D. Twesten,and R. Q. Hwang. 1998. “SiGe IslandShape Transitions Induced by ElasticRepulsion.” Phys. Rev. Lett. 80: 4717–4720.

Hamilton, J. C. 1997. “Frenkel-Kontorova Molecular Dynamics Modelfor Strained Heteroepitaxial FilmGrowth.” Paper presented to the APSInternational Conference on Computa-tional Physics, Santa Cruz, CA, 25–28August.


Hamilton, J. C. 1997. “Frenkel-Kontorova Molecular Dynamics Modelfor Strained Heteroepitaxial FilmGrowth.” Paper presented to theGordon Conference on Thin-Film andCrystal Growth Mechanisms, Ply-mouth, NH, 6–11 July.

Hannon, J. B., N. C. Bartelt, B. S.Swartzentruber, and G. L. Kellogg.1998. “LEEM Measurements of StepEnergies at the (001) Surface of HeavilyBoron-Doped Silicon.” Surf. Rev. andLett., accepted.

Hannon, J. B., N. C. Bartelt, B. S.Swartzentruber, J. C. Hamilton, and G.L. Kellogg. 1997. “Step Faceting at the(001) Surface of Boron-Doped Silicon.”Phys. Rev. Lett. 79: 4226–4229.

Kellogg, G. L. 1997. “Direct Observa-tions of the Effect of ChemisorbedHydrogen on Single-Atom SurfaceDiffusion.” Paper presented to the 18th

IUVSTA Workshop on Diffusion andGrowth in Ultrathin Layers (Invited),New Castle, Australia, 4–22 November.

Kellogg, G. L. 1997. “Direct Observa-tions of the Effect of Hydrogen onSingle-Atom Surface Diffusion.” Paperpresented to the 1997 Symposium ofthe Pacific Northwest Section of theAmerican Vacuum Society (Invited),Troutdale, OR, 18–19 September.

Kellogg, G. L. 1997. “Field Ion Micro-scope Studies of the Effect of Hydro-gen on Single-Atom Surface Diffusion.”Paper presented to the 44th Interna-tional Field Emission Symposium,Tsukuba, Japan, 7–11 July.

Kellogg, G. L. 1997. “Hydrogen Inhibi-tion of Exchange Diffusion on Pt(100).”Paper presented to the 44th NationalSymposium of the American VacuumSociety, San Jose, CA, 20–24 October.

Kellogg, G. L. 1997. “Hydrogen Inhibi-tion of Exchange Diffusion on Pt(100).”Phys. Rev. Lett. 79: 4417–4420.

Kellogg, G. L. 1998. “Mechanisms andEnergetics of Cluster Nucleation andDiffusion on Surfaces.” Paper pre-sented to the 9th International Sympo-sium on Small Particles and Inorganic

Clusters (Invited), Lausanne, Switzer-land, 1–5 September.

Pohl, K., M. C. Bartelt, J. de la Figuera,N. C. Bartelt, and R. Q. Hwang. 1998.“Identifying the Forces Responsible forSelf-Assembled Nanostructures.”Nature, accepted.

Schmid, A. K., R. Q. Hwang, and N. C.Bartelt. 1998. “Predicting the Future ofa Complicated Surface Structure: GrainCoarsening of P(2x2)O/Ru(0001).”Phys. Rev. Lett. 80: 2153–2156.

Swartzentruber, B. S. 1997. “Atomic-Scale Dynamics of Atoms and Dimerson the Si(001) Surface.” Surf. Sci. 386:195.

Swartzentruber, B. S. 1998. “Fundamen-tals of Surface Step and Island Forma-tion Mechanisms.” J. Crystal Growth188: 1.

Other

Bartelt, N. C. 1998. “Driving Forces forSelf-Assembly on Surfaces: Phonons inVacancy Island Lattices in Ag Films onRu(0001).” Paper presented to theAmerican Association of CrystalGrowth West Meeting, Fallen Leaf, CA,10 June.

Bartelt, N. C. 1997. “The Different Rolesof Near and Far from EquilibriumTheories of the Evolution of SurfaceMorphology.” Paper presented to theMaterials Research Society Meeting,Boston, MA, 5 December.

Feibelman, P. J. 1998. “The Forces thatControl How Metal Surfaces Evolve.”Paper presented to the Colloquium,Arizona State University, Tempe, AZ, 26February.

Feibelman, P. J. 1997. “The Forces thatControl How Metal Surfaces Evolve.”Paper presented to the Colloquium,University of Texas–El Paso, El Paso,TX, 15 April.

Feibelman, P. J. 1998. “Vibrations of Oon Stepped Pt(111).” Paper presentedto the March American PhysicalSociety Meeting, Los Angeles, CA, 17March.

Floro, J. A. 1997. “Epitaxy with anAttitude: Real-Time Studies of Coher-ent Islanding Kinetics During SiGe/SiMolecular Beam Epitaxy.” Seminar,Johns Hopkins University, Baltimore,MD, 17 September.

Floro, J. A. 1997. “Epitaxy with anAttitude: Real-Time Studies of Coher-ent Islanding Kinetics During SiGe/SiMolecular Beam Epitaxy.” Seminar,University of Texas, El Paso, TX, 1October.

Floro, J. A. 1997. “Evolution of Self-Organized SixGe1-x Island Arrays.”Paper presented to the Fall MRSMeeting (Invited), Boston, MA, 1–5December.

Floro, J. A. 1998. “SiGe Island Forma-tion Kinetics Real-Time Studies ofCoarsening Shape Transitions and Self-Assembly.” Paper presented to the 16th

Annual Conference on Crystal Growthand Epitaxy, Fallen Leaf Lake, CA, 10June.

Hamilton, J. C. 1997. “Dislocations,Diffusion, and Heteroepitaxial FilmGrowth.” Paper presented to PhysicsColloquium at University of Texas–ElPaso (Invited), El Paso, TX, 26 Novem-ber.

Hamilton, J. C. 1998. “DislocationsDuring Thin-Film Growth and Indenta-tion.” Seminar, LANL, Los Alamos, NM,June.

Hamilton, J. C. 1997. “Early Stages ofHeteroepitaxial Film Growth onMetals.” Paper presented to the 15th

Conference on Crystal Growth andEpitaxy (Invited), Fallen Leaf Lake, CA,1–4 June.

Hamilton, J. C. 1997. “Initial Growth ofHeteroepitaxial Films on Close-PackedMetal Substrates.” Paper presented tothe Fall MRS Symposium (Invited),Boston, MA, 1–5 December.

Swartzentruber, B. S. 1997. “DirectMeasurements of Atomic-Scale SurfaceKinetics on Si(001).” Paper presentedto the Annual Meeting of the AmericanVacuum Society, San Jose, CA, 20–24October.


3502.230

Enabling Science andTechnology for Cold-SprayDirect Fabrication

M. F. Smith, D. L. Gilmore, J. E.Brockmann, R. C. Dykhuizen, R. A.Neiser, Jr.

Cold-spray processing (CSP) is anew technology that can rapidly deposit(mm/second) metals, polymers, andcomposites at temperatures < 200°Celsius by accelerating powder particlesup to 600–1000 m/s in a supersonic gasjet. Sandia envisions a radical newdirect fabrication technology in which ahighly focused CSP particle beam with arobotic positioning system can spray-fabricate single- or multimaterialcomponents directly from a computermodel. Build rates should be higher thanpresent layer-wise direct fabricationtechniques and, since CSP particles arenever melted, superior surface finishes,microstructures, and properties might beachieved (finer grain size, no brittlephases, minimal oxidation, less residualstress, etc.). CSP might also depositfunctionally graded or layered materialsat low temperatures, eliminating joiningoperations, simplifying design/fabrica-tion, reducing part counts, and decreas-ing stress cracking (e.g., aluminum canbe CSP-deposited directly onto smooth,unprepared glass with excellent adhe-sion.) CSP may even be a green alterna-tive to technologies such as electroplat-ing, soldering, and painting. A primarytechnical barrier is focusing the particle

stream. Theory indicates major techni-cal challenges, but a noncontactfocusing technique known as anaerodynamic lens (AL) might work. TheAL was originally developed withsubmicron particles at subatmosphericpressures. Sandia previously establisheda new cold-spray capability and success-fully focused a beam of 15+ micronparticles down to ~ 1 mm at atmosphericpressure with subsonic gas velocities.Later, we will test higher-pressure ALdesigns and spray-fabricate proof-of-concept shapes commensurate with thelevel of focusing achieved. We will alsocharacterize the resulting materialproperties.

Tasks included successfullydesigning/testing multistage aerody-namic focusing; enhancing understand-ing through substantial experimental/modeling progress; and preliminarycharacterization of cold-sprayedmaterials. Based on computationalmodeling, we built a three-lens steppedfocusing system and aerodynamicallyfocused 15+ micron aluminum par-ticles in a subsonic helium jet down toa beam ~ 1 mm in diameter underambient atmospheric conditions(substantial improvement over ~ 5 mmbeam achieved previously). We arecurrently building a final design forfocusing under actual cold-sprayconditions. Modeling/variable sensitiv-ity experiments confirmed our analysisof key variable effects; for example,changing from nitrogen to helium candouble particle velocity; doublingnitrogen temperature can increase

particle velocity by one-third, but a30% reduction in gun inlet nitrogenpressure reduces particle velocities byonly ~ 3%. Our results show that inletgas temperature is more importantthan indicated by the Russian inven-tors of cold spray. Currently, we aremodeling and experimentally studyingthe impact of copper particles cold-sprayed onto steel. Also, we success-fully cold-spray–deposited copper,aluminum, stainless steel, a nickel–based alloy, and a nanophase tungstencarbide/cobalt wear coating. Micro-structures have similarities to ther-mally sprayed materials but withhighly angular features and no appar-ent evidence of melting or increase ingrain size. Some deposits exhibitcompressive residual stress. Copperdeposited in an ambient air environ-ment has no measurable increase inoxygen content over the feed powder.

Publications

Refereed

Dykhuizen, R. C., and M. F. Smith. 1998.“Gas Dynamic Principles of ColdSpray.” J. Thermal Spray Technol. 7(June): 205–212.

Smith, M. F., R. A. Neiser, D. L. Gilmore,and R. C. Dykhuizen. 1998. “Cold-SprayDeposition Material ConsolidationWithout Melting or Solidification.”Paper presented to the GordonConference on High-TemperatureMaterials, Processing, and Diagnostics(Invited), Plymouth, NH, 19–24 July.


3502.260

Freeforming of Ceramics andComposites from ColloidalSlurries

J. Cesarano, III, M. T. Ensz, M. L. Griffith,M. R. Baer, D. J. Schmitt

Sandia will develop a model–based direct freeform fabricationtechnique for ceramic, metal, or gradedcomposite components. These compo-nents are fabricated by computer-controlled dispensing of colloidalsuspensions through an orifice. Anyconceivable 2-D pattern may be writtenlayer-by-layer into a 3-D shape. Our goalis to develop model–based processingrules that will aid in the development ofslurries with the appropriate rheology,density, and drying kinetics to ensureprocess success for a variety of ceramicsand composites. Software and equip-ment development is also essential forprecise control of layer thickness andfeature resolution.

Development of this techniqueinto a manufacturing process requirescomputer simulations of the relevantphysical phenomena; materials exper-tise for tailoring colloidal slurry proper-ties and processing dissimilar materials;software and equipment expertise forcomputer-aided design (CAD) modelconversion; and robotics expertise forprocess optimization and incorporationof knowledge–based processing capa-bilities with closed-loop, sensor–basedcontrol.

This work will directly impact theproduction of neutron tubes and ceramicfixtures for switch tubes.

We made significant progresstoward scientific understanding ofslurry behavior, fabrication techniques

for reliable parts with good properties,fabrication of novel structures forceramic/metal joins, development ofnew material systems, software,modeling of flow, and sensing.

For aluminum oxide, in particu-lar, we studied the aging process ofslurries, resulting in substantial time-savings for slurry preparation. Slurriescan now be processed in two daysinstead of three weeks, and slurriesmay be frozen and stored until needed.This, along with the development ofcontrolled drying on wet plastersubstrates, yields reliable parts withgood tolerance. The density, micro-structure, and mechanical propertiesare comparable to aluminum oxidethat is traditionally isopressed andmachined. Therefore, we selected analuminum oxide Defense Programs(DP) neutron-tube component and areattempting to fabricate it with ourtechnology. Another unanticipatedaccomplishment was the developmentof corrugated ceramic preforms that,when infiltrated with metal, can formstrong interlocking joins with a gradedmacrostructure. We fabricated crack-free alumina/aluminum structures.

We also developed slurries forthe fabrication of lead zirconatetitanate (PZT), ZnO, Kaolin, andalumina/Mo composites. We are justbeginning multimaterial fabrication.

Developments for software,modeling, and sensing. We developedsoftware that can slice a CAD file intolayers and create machine commandsfor slurry deposition that fills in thelayers. We now have the ability tobuild simple parts directly from a CADfile. We also developed a 3-D model offluid flow through a nozzle and onto amoving substrate, the first of its kind.

In addition, we are developing astructured lighting sensor for real-timedimensional measurement of parts.

Publications

Refereed

Cesarano, J., and R. Segalman. 1998.“Robocasting Provides MoldlessFabrication from Slurry Deposition.”Ceramic Industry 148 (April): 94–102.

Cesarano, J., B. King, and H. Denham.1998. “Recent Developments inRobocasting of Ceramics andMultimaterial Deposition.” Proc. SolidFreeform Fabrication Symp. (Austin, TX,7 August).

Denham, H., J. Cesarano, and B. King.1998. “Mechanical Behavior ofRobocast Alumina.” Proc. SolidFreeform Fabrication Symp. (Austin, TX,7 August).

King, B., S. Morissette, H. Denham, J.Cesarano, and D. Dimos. 1998. “Influ-ence of Rheology on DepositionBehavior of Ceramic Pastes in DirectFabrication Systems.” Proc. SolidFreeform Fabrication Symp. (Austin, TX,7 August).

Other

Cesarano, J. 1997. “Slurry Processingof Technical Ceramics withRobocasting.” Presentation forAlliedSignal Corporation in prepara-tion for a joint proposal to DARPA,Morristown, NJ, September.

Cesarano, J., B. King, and T. Baer. 1998.“Direct Fabrication of Ceramics andComposites from Slurries: RobocastingTechnology.” Paper presented to thePacific Rim International Conferenceon Advanced Materials and Process-ing, Honolulu, HI, July.


3502.250

Intelligent Polymers forNanodevice PerformanceControl

G. M. Jamison, M. J. Carr, J. A. Shelnutt,R. S. Saunders, D. R. Wheeler, D. A. Loy

The purpose of this project is todevelop organic materials systems thatcan be predictably manipulated to alterthe fundamental optical, electrical, andrheological properties of the materials.Technical insights led to a largeremphasis on manipulating the electricalproperties of organic materials thanreflected on the original project plan. Wewill continue to pursue manipulation ofboth polymer electrical and rheologicalproperties through light, heat, or redox–based stimuli.

Molecular modeling of a family ofmetal porphyrin-terminated polyenesconfirmed molecular orbital overlapbetween polyene linkers and porphyrintermini in model systems; we predictedphotophysical properties to reflect thesefavorable interactions. Sandia begansynthetic efforts on simple polyenesystems.

Chemical amplification continuesto be an attractive strategy for affectingmacroscopic changes in polymerrheological properties and to leveragewith existing in-house expertise, e.g.,photoresist materials. We are broaden-ing our approach in chemical amplifica-tion to include catalyst systems that willbe potentially more effective thanpreviously investigated systems.Application of this approach to acid- andbase-sensitive polymer systems contin-ues and has allowed us to addresstechnical issues of interest to nationalsecurity and weapons customers.

This year the project extendedcomputational methods to includesemiempirical molecular orbitalmodeling studies of metal porphinesas candidate redox ligands for electri-cal manipulation of polyacetyleniclinkers. These theoretical results allowphotophysical property prediction of

porphyrin-terminated polyenes. Weprepared simple diene- and triene-bridged systems for validation of themodeling predictions.

Our experimental work includesthe preparation of organic monomersfor potential light-induced conversionof electrically insulating organicpolymers to conducting materials andnovel hybrid materials bearingconducting organic nanodomains inphase-separated block polymers.Investigations of structural polymersthat can be degraded by light-inducedliberation of chemical species ad-vanced. Also, we prepared reductivelysensitive polyurethanes for potentialhydrogen-detection applications(verification of better efficiency).Finally, we applied new metathesiscatalysts to the development of novelhybrid polymers. The oligomerizationbehavior of phosphaalkyne monomerswith metal alkylidenes is a fundamen-tal advance in the chemistry ofphosphaalkynes and suggests thatpolyconjugated materials may beaccessible by this route.

Publications

Refereed

Jamison, G. M., D. R. Wheeler, R. S.Saunders, and D. A. Loy. 1998. “DoublePhosphaalkyne Insertion to a TungstenAlkylidene: Formation of a NovelDiphosphametallabicyclo-butane.” J.Amer. Chem. Soc., submitted.

3502.270

Quantum Dot Arrays

J. E. Martin, R. A. Anderson, D. R.Jennison, P. N. Provencio, J. P. Wilcoxon

The goals of Sandia’s research areto investigate methods of synthesizingquantum dot arrays (QDAs)—superlattices of nanoclusters—and tocharacterize and understand theproperties of these novel materials. It iswell known that nanoclusters have

many unusual properties, includinganomalous optical properties, size-dependent bandgaps, high catalyticactivity, low melting temperature,anomalous magnetic properties, etc.However, the formation of cluster–basedmaterials requires that thesenanoclusters be isolated in a matrix toprevent the spontaneous sintering ofclusters to form a bulk material. We canaccomplish this by forming theseclusters into periodic arrays whereclusters are separated by an isolatingmatrix. These periodic arrays mayexhibit coherent effects, or may simplybe efficiently close-packed materials.

We developed robust syntheticprocedures to synthesize very narrow-size distribution metal nanoclusters(platinum [Pt], gold [Au], palladium[Pd], ruthenium [Rh]) by systemati-cally exploring and optimizing thereactants and procedures. We devel-oped extraction methods to purify theas-synthesized nanoclusters so theyspontaneously form 2-D and 3-Dsuperlattices without the need for sizefractionation. The 3-D QDAs form inseveral crystalline habits. We devel-oped software to obtain very detailedstructural information from tunnelingelectron microscope (TEM) images of2-D QDAs and used this to study theability of systematically chosen thiolcapping agents to control the latticecell size and interparticle gaps—important in controlling tunnelingcurrents through these materials. Weformed a stable microemulsion of Ptnanoclusters in octane—useful inincorporating nanoclusters intoperiodic mesoporous silica. We madeconductivity measurements on thinfilms of QDAs and found that thesintering temperature of Ptnanoclusters is only ~ 200°C, far belowthe melting temperature of bulk Pt,1772°C, which led to further investiga-tions to use these materials as her-metic seals. We showed the directwriting of wires at low temperatures tobe possible, as was the selected laserannealing of nanocluster thin films to


form conducting Pt and Au wires.Optical studies show that the opticalabsorption properties of QDAs arequite different from dilute solutions ofnanoclusters, which we believe isbecause of local field corrections dueto nearby dipole radiators. Nonlinearoptical studies on Au QDAs demon-strate a very large third nonlinearoptical coefficient, measured in four-wave degenerate mixing experiments.A university collaboration showed that2-D QDAs on graphite can be manipu-lated with a scanning-tunnelingmicroscope.

Publications

Refereed

Durston, P. J., J. Schmidt, R. E. Palmer,and J. P. Wilcoxon. 1997. “STM Imagingof Ordered Coated Cluster Layers onGraphite.” Appl. Phys. Lett. 71 (Octo-ber): 2940–2942.

Durston, P. J., R. E. Palmer, and J. P.Wilcoxon. 1998. “Manipulation ofPassivated Gold Clusters on Graphitewith the Scanning Tunneling Micro-scope.” Appl. Phys. Lett. 72 (January):176–178.

Newcomer, P. P., J. P. Wilcoxon, J. E.Martin, and J. G. Odinek. 1997. “Studiesof Pt and Au NanoclusterSuperlattices.” Paper presented to the1997 Fall Meeting of the MaterialsResearch Society, Boston, MA, 1December.

Wilcoxon, J. P. 1997. “An Overview ofNanocluster Research at SandiaNational Laboratories.” Paper pre-sented to the Department of PhysicsColloquium, University of New Mexico,Albuquerque, NM, 9 October.

Wilcoxon, J. P., J. E. Martin, and P. P.Newcomer. 1997. “ChromatographicCharacterization of Metal and Semi-conductor Nanoclusters.” Paperpresented to the 1997 Fall Meeting ofthe Materials Research Society,Boston, MA, 1 December.

3502.280

Laser-Assisted Arc Weldingfor Aluminum Alloys

P. W. Fuerschbach

There exists a strong need in thedefense programs and automotive,aerospace, and transportation industriesfor a rapid, robust, high-quality processfor welding aluminum alloys, especiallyfor relatively thin-gauge product. Whilelaser beam welding is widely applied inthese industries, it has not provedvaluable for aluminum because ofproblems with reflectivity and weld jointvariability. Sandia intends to develop anew welding process by combining afiber-optic–delivered materials-process-ing laser with a small arc-welding heatsource. The new laser-assisted arc-welding (LAAW) process will couple theprocess advantages of the two heatsources and will also enable processcapabilities never before envisioned inarc welding. The project is a System ofLaboratories (SOL) collaboration amongOak Ridge National Laboratory, IdahoNational Electrical Engineering Labora-tory, Sandia National Laboratories, andY12. Team members will combine theirwelding expertise to develop thescientific understanding and engineeringmethods required for the novel process.We anticipate that the team establishedthrough this SOL interaction will allowthe U.S. to successfully compete withinternational entities in developing (andhence owning) advanced joiningtechnologies.

Our efforts this year in LAAWfurthered our fundamental andpractical understanding of hybridlaser/arc-welding technology. Impor-tant modifications to the Sandia-

developed LAAW end-effector contin-ued this year as new experimental dataindicated weaknesses in the prototype.We produced a full set of dimensioneddrawings of the end-effector compo-nents and the combined assembly. Wefound variations in the orifice gas flowto produce combined process weldsthat appeared similar to deep-penetra-tion laser welds. We obtained high-fusion-zone depth-to-width ratios with150 W of laser and 400 W of arc power.These results indicate that by carefullycontrolling the LAAW process param-eters, we can independently select awide range of weld-pool geometrieswith this process. We also modified theend effector to be compatible withcontinuous-wave (CW) CO2 laser beamwelding. Metallography of early weldswith this CO2 laser indicated that thearc does not penetrate as deeply intothe laser keyhole as was observed forNd:YAG laser welding. Presently, itappears that the arc plasma is absorb-ing the laser beam and preventing thelaser beam from penetrating into theweld pool.

Based on the success of the SOLcollaboration, the laboratory andindustrial participants submitted ajoint proposal to the DOE Office ofIndustrial Technology to furtherdevelop this technology for steel-welding applications. DOE has ap-proved the joint project.

Publications

Other

Fuerschbach, P. W., and F. M. Hooper.1998. “Laser-Assisted Non-ConsumableArc-Welding Process Development.”Paper presented to the 79th AnnualAWS Convention, Detroit, MI, 27 April.


3502.310

Reactivity of Metal-OxideSurfaces

A. G. Sault, R. Q. Hwang, J. A. Ruffner,D. R. Jennison, B. S. Swartzentruber

Sandia will use a combination ofexperimental and theoretical techniquesto explore atomic-scale defect chemistryon technologically important surfaces,with the goal of determining the salientfactors that control defect chemistry. Theformation, mobility, reactivity, anddissolution of atomic-scale surfacedefects play important roles in materialsareas such as catalysis, corrosion, thin-film growth, semiconductor processing,sensors, and magnetic devices. Impor-tant defects include single adatoms,surface steps and kinks, dislocations,and vacancies. It is generally believedthat a small number of localized surfacedefects may be particularly reactive andthereby dominate the surface chemistryof many materials. While past studies ofthis important problem have beenlimited by an absence of appropriateexperimental probes for imaging atomic-scale defects, the recent advent ofspecialized scanning probe micros-copies largely overcomes this problemand now allows more detailed studies ofdefect chemistry than previouslypossible. The unique atom-trackingscanning-tunneling microscope (AT-STM) recently developed at Sandia is aparticularly powerful new technique thatallows measurement of atomic-scalekinetic processes on a time scale that is

more than three orders of magnitudefaster than previous techniques.Similarly, a lack of sufficient computingpower has severely limited previoustheoretical studies of defect properties.The recent development of massivelyparallel (MP) computational techniquesat Sandia, which now allow calculationson systems containing hundreds ofatoms per unit cell, will enable studiesof surface defects with a level of detailand sophistication far greater thanpreviously possible. By studying well-defined, well-ordered surfaces, we cangreatly simplify the study of defectchemistry and obtain detailed funda-mental information on defect formationand reactivity. Coupling experimentalresults with theoretical studies will allowthe development of models that explain,predict, and ultimately help to controlsurface defect reactivity.

We designed and built a new STMfor investigation of adsorbate kineticson metal substrates. This microscopehas the capability to perform atom-tracking studies and will be used tostudy local reactivity at well-character-ized defect sites.

We performed STM investiga-tions of the modification of dislocationnetworks present on strained metalfilms upon controlled exposure tomolecular oxygen. Our study showsthat oxygen reacts with a two-mono-layer copper (Cu)-strained film, at firstonly at threading dislocations, andthen through the modification of thefilm mesoscopic structure and removalof atoms from the film. The process

responsible for these changes, whichis consistent with our STM observa-tions, is the local extraction of the Cuatoms from the film due to oxygenatoms.

We deposited magnesiumvanadate and bismuth molybdate filmson Si(100) substrates and investigatedthe effects of deposition variables suchas temperature and oxygen pressureon film composition and structure.Initial results are leading us to im-proved methods for deposition thatwill allow us to accurately reproducemixed metal-oxide stoichiometries andorientations of desired crystallinephases.

We studied the perfect interfacesbetween Al2O3 ultra-thin films andAl(111), Mo(110), and Ru(001),discovering that the driving factor ininterface geometry is the strongchemisorption of oxygen. In prepara-tion for studying adsorbate interac-tions with surface dislocations, wecomputed atomic adsorbates H, O, andS on 1ML Cu/Ru(001), and comparedthe results to ordinary Cu and to Custrained at the Ru lattice constant.These calculations are helping us tounderstand the roles of strain versuschemical effects in binding.

Publications

Refereed

Carpinelli, J. M., and B. S.Swartzentruber. 1998. “DetailedEnergetic Interactions of Adsorbed SiDimers on Si(001).” Surf. Sci. 411: L828.


3502.320

Exploiting LENS TechnologyThrough Novel Materials

J. A. Brooks

Laser-Engineered Net Shaping(LENS) is a direct fabrication processin which metal powders are depositedinto a laser-melted pool, with succeed-ing layers deposited to build up complexengineering shapes. This process is arapid, low-cost, low-footprint, directfabrication technique that lends itself tothe concept for advanced manufacturing.However, previous work developedLENS as an advanced manufacturingtool rather than exploiting its potentiallyunique attributes. These attributesinclude real-time control of microstruc-ture, tailored material properties atdifferent locations in the same part, theproduction of graded thermal expansionparts, etc. This project seeks to developa science–based approach to utilizeLENS to process for properties in acontrolled fashion, or for the productionof components that cannot be madeusing other methods. Three materials—atool steel with an optimized structure/property mix, a graded structure basedon stainless-steel compositions, and aceramic-to-metal transition—are novelmaterial systems through which we willinvestigate and exploit LENS.

We will achieve this goal by firstdeveloping a thorough understanding ofthe process in terms of how it impactssolidification and solid-state microstruc-ture development. Additionally, we willstudy and understand the uniqueattributes and capabilities of the LENSprocess. From this knowledge base, we

will design and produce a suite ofexperimental materials and structuresthat optimally exploit the LENSprocess and demonstrate its uniquepotential. We will develop an under-standing of the residual stresses inLENS parts and what mitigationtechniques may be available.

We used a tool steel to determinecritical metallurgical-related aspects ofthe LENS process that are requiredto exploit the technology in thedevelopment of novel structures. Wedetermined the parameter space inwhich good-quality structures couldbe fabricated, and we measured thethermal cycles associated with theseparameters using thermocoupletechniques. These (first-ever) thermalmeasurements showed that highcooling rates on the order of 103°–104°K/s are developed and are criticalto the development of many novelmicrostructures. We also evaluatedother noninvasive thermal measure-ment techniques that appear promis-ing for process and microstructurecontrol. We determined the range inscan speeds and subsequent solidifica-tion velocities and thermal gradientsthat can be achieved and that arerequired input parameters to thesolidification and microstructuralmodels. We developed a microstruc-tural, carbide-coarsening model thatwe are integrating with processthermal models, validating with theexperimental results, and using topredict hardness and tensile strengthof H13 tool steel. We conductedcharacterization of the H13 micro-structure and properties for modeldevelopment and comparison with

model prediction. We also evaluatedexperimental techniques to determinethe magnitude of residual stresses thatcan lead to part distortion. We used aholographic hole-drilling technique toshow that the residual stresses in 316stainless steels were close to yield-strength values. An outstandingfeature of this technique is its ease ofdata collection in time and effort. Wealso measured residual stresses as afunction of process parameters in aseries of H13 tool steel samples, whichwill serve as a comparison to futurefinite-element model predictions.

Publications

Refereed

Griffith, M. L., M. E. Schlienger, L. D.Harwell, M. S. Oliver, M. D. Baldwin, M.T. Ensz, J. E. Smugeresky, M. Essien, J.A. Brooks, C. V. Robino, W. H.Hofmeister, M. J. Wert, and D. V.Nelson. 1998. “Thermal Behavior in theLENS Process.” Proc. Solid FreeformFabrication Symp. (Austin, TX, 10–12August).

Schlienger, M. E., D. Dimos, M. Griffith,J. Michael, M. Oliver, T. Romero, and J.E. Smugeresky. 1998. “Near Net-ShapeProduction of Metal Components UsingLENS.” Proc. 9th Solid Freeform Fabrica-tion Symp. (Honolulu, HI, 12–16 July).

Schlienger, M. E., J. Brooks, M. Griffith,M. Oliver, T. Romero, and J. E.Smugeresky. 1998. “Laser-EngineeredNet Shaping.” Paper presented to theAutomotive Applications of ThermalSpray Technology Conference,Romulus, MI, 3 June.










COMPUTER

SCIENCES

Computer Sciences projects seek to developrevolutionary capabilities in high-performancecomputing and simulation technologies that work atsystems levels. Computer Sciences consists of threeresearch areas: (1) development of distributedcomputing technologies that will enable computingat the 30- to 100-teraflop scale; (2) development oftechnologies that address key science and engineeringchallenges related to massively parallel (MP)computing, algorithms, systems software, virtualenvironments, and advanced simulations; and (3)the encouragement of the development ofrevolutionary ideas in computational and computersciences and mathematics. The DOE AcceleratedStrategic Computing Initiative (ASCI) is also animportant area of emphasis. The advent of large, MP supercomputers led tomodeling more complex problems, particularlyturbulent, chemically reacting flows, but the processbecame mired in thousands of equations, preventingfocusing on the real issues. Aztec, an MP softwarelibrary that grew out of a chemically reacting flowproject called MPSalsa, made the modeling easier.It helped solve very large, chemically reacting flowproblems, now containing tens of millions ofunknowns, on large-scale parallel machines. Engineersuse MP supercomputers to solve scientific computingproblems that previously were nearly unsolvable.Aztec was ported to the new Sandia-Intel TeraflopComputer, which has achieved applications of over200 gigaflops. Aztec has helped to make parallelcomputing the standard platform for large-scalesimulations and design codes. Industry and universities use Aztec for ground-water flow with toxic-waste transport modeling, heat-transfer modeling for manufacturing processes,nuclear material nonproliferation studies, cardiacdefibrillation simulations, compressible-flowcalculations for hypersonic vehicles, automotive tiremanufacturing design calculations, fire simulations,and more. There are now over 400 external researchlicenses for the Aztec library. The Aztec library is part of Sandia’s leading-edgescientific simulation capabilities. The Aztec projectwon an R&D 100 Award, and the MPSalsa code wasa finalist in the Gordon Bell Competition for high-performance scientific simulation on parallelsupercomputers. This technology has had a hugeimpact on ASCI and on parallel computing technology��





3504.090

Gradient-Driven Diffusion ofMulti-Atom MoleculesThrough Macromoleculesand Membranes

G. S. Heffelfinger, A. P. Thompson, D. J.Hobbs, D. M. Ford

The goals of this work arethreefold: (1) to develop a method formodeling diffusion of multi-atommolecules through macromoleculesunder conditions of a chemical potentialgradient, (2) to develop a companionparallel algorithm, and (3) to apply thenew method to three sample problems.Currently, no such method exists.Therefore, many important industrialand technological materials problemswhere gradient-driven diffusion of multi-atom molecules is the predominantphenomenon are beyond the reach oftoday’s molecular simulation, includingthe three that we plan to study. Theseare (1) diffusion in polymers, (2) chiralpolymer membranes for separatingracemic mixtures, and (3) the perme-ation of drug analogs through lipidbilayers.

We finished extending themethod to model gradient-drivendiffusion through bonded (macromo-lecular) systems. Other work includedenabling the insertion and deletion ofsmall multi-atomic species. This willallow steady-state gradients to beestablished for small multi-atomics(e.g., O2) diffusing through polymers(e.g., isobutylene). We investigated thissystem (O2 diffusing in isobutylene)with the method.

We also developed andprototyped a method of establishingchemical potential gradients of largermulti-atomic species without carryingout insertions and deletions. Weaccomplished this by adding two

pistons to the system to control thepressure on each end of the system.We then prototyped the method on abinary atomic system.

Publications

Refereed

Ford, D. M., and G. S. Heffelfinger. 1998.“Massively Parallel Dual-ControlVolume–Grand Canonical MolecularDynamics with LADERA. II. Gradient-Driven Diffusion Through Polymers.”Molecular Phys. 94 (15 July): 673.

Heffelfinger, G. S., and D. M. Ford. 1998.“Massively Parallel Dual-ControlVolume–Grand Canonical MolecularDynamics with LADERA. I. Gradient-Driven Diffusion in Lennard-JonesFluids.” Molecular Phys. 94 (15 July):659.

Thompson, A. P., D. M. Ford, and G. S.Heffelfinger. 1998. “Direct MolecularSimulation of Gradient-DrivenDiffusion.” J. Chem. Phys. 109 (15October): 1.

Thompson, A. P., D. M. Ford, and G. S.Heffelfinger. 1998. “Direct MolecularSimulation of Gradient-Driven Diffu-sion.” Proc. 9th CIMTEC–World Congressand Forum on New Mater. (July)(Florence, Italy, 14–19 June).

Van Swol, F., and G. S. Heffelfinger.1996. “Gradient-Driven Diffusion UsingDual-Control Volume–Grand CanonicalMolecular Dynamics (DCV–GCMD).”Proc. Mater. Res. Soc. Symp. 408(Boston, MA, November): 299.

Other

Ford, D. M., and G. S. Heffelfinger. 1997.“Gradient-Driven Diffusion of SmallPenetrants in Polymers Using Dual-Control Volume–Grand CanonicalMolecular Dynamics (DCV–GCMD).”Paper presented to the Spring Meetingof the American Physical Society,Kansas City, MO, 17–21 March.

Ford, D. M., and G. S. Heffelfinger. 1997.“Modeling Gradient-Driven Diffusion ofSmall Molecules in Polymers with Dual-Control Volume–Grand CanonicalMolecular Dynamics (DCV–GCMD).”Paper presented to the AmericanInstitute of Chemical EngineersConference, Los Angeles, CA, 17–21November.

Ford, D. M., A. M. Thompson, P. I. Pohl,and G. S. Heffelfinger. 1998. “Gradient-Driven Diffusion of Liquids andAdsorbed Fluids Using Dual-ControlVolume–Grand Canonical MolecularDynamics.” Paper presented to the 5th

LIBLICE Conference on the StatisticalMechanics of Liquids, Zelzna Ruda,Czech Republic, 7–12 June.

Heffelfinger, G. S. 1996. “Dual-ControlVolume–Grand Canonical MolecularDynamics.” Paper presented to the 4th

Joint Conference on ComputationalMathematics, Chelyabinsk, Russia, 20–24 May.

Heffelfinger, G. S., and F. van Swol.1995. “Diffusion in Non-Ideal MixturesUsing Dual-Control Volume–GrandCanonical Molecular Dynamics.” Paperpresented to the American Institute ofChemical Engineers Conference, MiamiBeach, FL, 13–17 November.

Thompson, A. P., and G. S. Heffelfinger.1998. “Molecular Dynamics Simulationof Gradient-Driven Diffusion in BinaryMixtures: Comparison of ChemicalPotential and Osmotic PressureApproaches.” Paper presented to theAmerican Institute of ChemicalEngineers Conference, Miami Beach,FL, 15–20 November.

Thompson, A. P., M. G. Martin, and G.S. Heffelfinger. 1998. “MolecularSimulation of Nonequilibrium Gradient-Driven Transport Processes: GasPermeation in Rubber Polymers.”Paper presented to the AmericanInstitute of Chemical EngineersConference, Miami Beach, FL, 15–20November.


3504.010

Parallel Quantum Chemistryfor Material Aging andSynthesis

C. F. Melius, E. J. Friedman-Hill, E. T.Seidl, J. L. Durant, Jr.

Computer simulations mustincrease their role in design, certifica-tion, and maintenance of weaponssystems as budgets shrink, yet designcycles shorten. Massively parallel (MP)computers offer the promise of predict-ing the aging of materials and optimiz-ing the synthesis of new materials.Sandia is developing a new hybridquantum chemistry (QC) procedure foraccurately calculating the thermochemi-cal properties of these materials. Theprocedure will incorporate a combina-tion of density-functional–based (DFT)methods and Hartree-Fock–basedmethods (HF, MP2), using various basissets for each calculation step. We willimplement all methods to run on the MPmachines as well as on distributedshared-memory machines. We willemploy intelligent agents to balance theworkload between machines andmethods.

This project will have a majorimpact on the Accelerated StrategicComputing Initiative (ASCI) program. Itwill provide the computational QCmethods necessary to treat the chemicaldegradation process occurring in theaging of the nuclear stockpile, includingpolymers, energetic materials, adhesion,and corrosion. The developed proce-dures will aid in the processing of newmaterials, such as semiconductors,protective coatings, and ceramics,coupling the molecular level to equip-ment design and process optimization.The thermochemistry will also aid in theareas of chemical warfare agent

destruction, environmental cleanup, andwaste minimization. This project willenable the MP machines to be effec-tively harnessed by QC applications.Furthermore, the resulting process forimplementing multiple coupled codes,using intelligent agents to maximize theeffectiveness of MP machines, will havespin-offs to other Sandia applicationsrequiring complex computer simulationmodeling.

We successfully developed abond-additivity-correction (BAC)procedure that can be applied to avariety of QC methods that willprovide accurate thermochemicalproperties. The procedure includesatomic and spin–based corrections inaddition to the bond–based correc-tions. The procedure works on the DFTmethods as well as on the Möller-Plesset perturbation theory methodsat second order and fourth order. Wealso showed that it works on the G2method, itself a composite of QCmethods. The key to the correction isthe use of a correction for an electrongeminal (or electron pairing). Thiswould occur not only when a chemicalbond is formed, but also when anegative ion is formed. Thus, theprocedure will work for charged aswell as neutral species. We found thatthe corrections are very basis-set-dependent. For the large basis sets, thecorrection can be negative, particu-larly for ionic bonds. For quantumchemical methods that are alreadyquite accurate, we found that thecorrection parameters need onlydepend on the atom types involved,rather than on the bonds themselves.This provides a bootstrapping proce-dure for obtaining the correctionfactors for lower levels of theory, usingthe higher levels of theory as refer-ences.

3504.020

Modeling Complex TurbulentChemically Reacting Flowson Massively ParallelSupercomputers

J. N. Shadid, T. M. Smith, S. P. Burns, A.G. Salinger, A. R. Kerstein, R. C. Schmidt,R. J. Cochran, K. D. Devine

This project will develop amassively parallel (MP), adaptive,unstructured finite-element (FE) code forsimulating 3-D high-Reynolds-numberand turbulent chemically reacting flowsin complex geometries. Importantapplications of such flows include the“crash-and-burn” scenario for safetycalculations for nuclear weaponstransport and storage (AcceleratedStrategic Computing Initiative [ASCI]-related); jet-mixed chemical reactordesign; internal combustion engineanalysis; high-performance compactheat-exchanger design for aircraft,automobiles, and chemical processplants; and high-temperature combus-tion process modeling for the destructionof hazardous waste. Currently, theselarge, multiple length- and time-scaleproblems can be solved only in 2-D for alimited number of species because of therequired computational resources. Thesedifficult problems strongly coupleturbulent momentum, thermal energy,and mass transfer with chemicalreaction kinetics, making current 2-Dmodels unsuitable. We constructed thesimulation code on the foundation of anexisting, successful, 3-D MP chemicallyreacting flow-simulation code(MPSalsa). State-of-the-art engineeringmodels for reaction kinetics in turbulentflow, thermal radiation in participatingmedia, and advanced turbulence modelsfor fluid flow and heat and mass transferwill be added to MPSalsa. We will alsoadd MP adaptive mesh methods,dynamic load-balancing techniques,high-order convection stabilizationmethods, and subgrid turbulent reactionmodels to enable the sharp resolution ofsteep gradients and multiple lengthscales in the flow. With the proposedcode development, MPSalsa will becapable of solving very large, strongly


coupled multiphysics turbulenceproblems with multiple time and lengthscales. This tool will be immediatelyuseful for Sandia’s weapons programresponsibilities (ASCI) as well as manyadvanced engineering technologyproblems for U.S. industry. As a result,Sandia’s recognized leadership role inlarge-scale multiphysics complex systemsimulation will be greatly strengthened,as will the capabilities of other inter-ested federal agencies (DOE, DoD) andU.S. industry.

We successfully completed thefollowing: (1) the implementation inMPSalsa of the participating mediaradiation model—a discrete ordinatesmethod capable of treating variableproperty flows, (2) the implementationin MPSalsa and testing of the higher-order hydrodynamic turbulencemodel—this is a large eddy simulation(LES) model with both a Smagorinskiand a k-equation-type subgrid model,(3) the calculation of a benchmarkparticipating media radiation problem,and (4) the implementation of adynamic equal order refinement and ageneral solution/grid transfer capabil-ity into MPSalsa.

The implementation of a higher-order turbulent species mixing andreaction model (the linear eddy model)is nearing completion and will soon beready for testing. We will also sooncomplete local mesh adaptivity (h-refinement) and the associateddynamic load-balancing capability.

Publications

Refereed

Devine, K. D., J. N. Shadid, A. G.Salinger, S. A. Hutchinson, and G. L.Hennigan. 1997. “Parallel, AdaptiveFinite-Element Methods for ChemicallyReacting Flow Simulations.” Proc. ACM/IEEE SC ’97 Conf. (San Jose, CA, 15–21November).

Devine, K. D., J. N. Shadid, A. G.Salinger, S. A. Hutchinson, and G. L.Hennigan. 1998. “Toward ParallelAdaptive Mesh Refinement for Chemi-cally Reacting Flow Simulations.” Proc.10th Internat. Conf. on Finite Elements inFluids 1 (Tucson, AZ, 5–8 January):285–290.

3504.050

Automated Geometric ModelBuilder Using Range ImageSensor Data

C. F. Diegert, L. M. Doran, J. T. Sackos

Sandia’s goal is to developalgorithms that automatically constructrealistic 3-D models of physical environ-ments based on range and opticalreflectance information collected withSandia’s scannerless range imager(SRI). We will design algorithms toanalyze and reduce the complexity ofthe data collected from multiple rangeimages taken from different perspec-tives, recognize and eliminate redundan-cies in the images, and integrate theminto a simplified geometric model. Theresulting model will be compatible withvirtual reality (VR) and computer-aideddesign (CAD) software. The algorithmswill be flexible enough to accommodatemassively parallel processing (MPP) fornational security applications involvinglarge volumes of data. The SRI is aunique camera system invented andpatented by Sandia that providesdistance and reflected light intensity toeach pixel in a field of view (FOV). Ithas no moving parts and is built with off-the-shelf (OTS) components. Theresulting capabilities could be used torapidly survey unknown terrain orhazardous environments, monitorremote sites for security, plan clandes-tine activity, and enhance the ability of

robotic systems to move about anenvironment based on a 3-D model.

Our field experimentation workdemonstrates our greatly improved SRIinstrument and visualization algo-rithms, and our new ability to achievea quick-turnaround 3-D data renderingon a transportable system. The 0.1-inch-range accuracy we established inthis experiment generated a lot ofexcitement and outside interest, and inthe context of reaching our automaticmodel-building goals, it demonstratedour new statistical fitting capabilities.We could not have established the 0.1-inch accuracy without first fitting theplanar surface models of the testcalibration targets. Beyond simplefitting tasks are the automatic model-building capabilities we obtain byapplying fitting and segmentationalgorithms together. We producedboth fitted plane models and trimmingcurves. While the considerable extratrouble of obtaining trimmed modelswas unnecessary for establishing asimple accuracy measure, it did allowus to present computer-generatedimaging of the fitted models and of theresiduals about the model. That is,adding the trimming summarizes theraw range-imaging information in amanner that helps us obtain insightfrom these data. We need the trimminginformation to produce fully formedmodels that load into a CAD or VRsystem. During the past year we alsoadded the capability to write summarymodels to DXF-format files.


3504.060

A Massively Parallel SparseEigensolver for StructuralDynamics Finite Element

G. M. Reese, D. M. Day, R. S. Tuminaro

Structural dynamics finite-element(FE) analysis is critical to applicationsin weapons, nonproliferation, spacesensors, and computational manufactur-ing. Sandia recently accepted stringentnew requirements essential to meet DOEobligations for stockpile stewardshipwithout nuclear testing. These applica-tions require modeling and simulationwith unprecedented fidelity and accu-racy. Such capabilities are buildingblocks for design optimization, modelvalidation, nondeterministic design, andvirtual testing for weapons and otherdefense programs. While Sandiadeveloped several codes for nonlinearstructural mechanics, we are developingfor the first time a structural dynamicsFE code with both frequency and time-domain solution capabilities forvibration and late-time shock-responseproblems. This code requires anessential component: a massivelyparallel (MP) eigensolver. Thiseigensolver will enable the solution ofhigh-fidelity structural dynamics models,as well as minimize the number ofengineering approximations (which areprone to error, time-consuming, anddifficult to automate). We developed aninitial version of an MP structuraldynamics eigensolver. A major hurdle inbuilding this eigensolver was theintegration of a sophisticated multilevelpreconditioner needed to solve theextremely ill-conditioned linear subprob-lems required by the eigensolver. A newparallel FE code, SALINAS, is a directoutgrowth of this project. We integratedthe new MP eigensolver into SALINAS.The combined code represents afundamental advance in Sandia’sstructural dynamics FE analysis capabili-ties. Simple all-hex-element models havebeen solved in parallel with up to800,000 equations (requiring one-half

hour of computation) and confirm thescalability of the overall algorithm. Thelargest eigen-solution previouslyperformed at Sandia involved fewerthan 200,000 equations. Our projectaddressed two critical tasks: improve-ment (robustness, memory, computationtime) of kernel algorithms within theiterative linear solver, and extension/application of the overall iterativealgorithm to more realistic structuraldynamics problems containing bothconstraint equations and more complexdiscretization schemes.

• We developed a sophisticatedstructural dynamics linear andeigensolver based on the Finite-Element Tearing and Interconnecting(FETI) parallel multilevel linear systemsolution method and the PARPACKparallel Krylov-subspace–basedeigensolver. FETI methods are multi-level iterative methods developed forstructural dynamics, an applicationarea in which iterative methods havenot previously been successful. Weexplored reorthogonalization methodsleading to increased robustness. Weincorporated this solver into theSALINAS parallel FE/structural dynam-ics code developed separately atSandia and improved the combinedsolver. We addressed domain decom-position issues related to convergenceand robustness. We developed a newgraph partitioner that eliminatesspurious subdomain mechanisms andaligns subdomain boundaries withcritical material interfaces. Similarfunctionality will be available in futureversions of the CHACO graph partition-ing package that is widely available.These enhancements make possiblerobust subdomain pseudo-inversecalculation and substantially enhancethe scalability of the FETI linear solver.We modified the coarse grid solver soan approximation of the operator issolved on the coarse space. We nowaccomplish the coarse solve byforming the sparse coarse linearsystem and applying a sparse directlinear solver. We also developed aprototype code that handles

multipoint constraints in two ways:Intersubdomain constraints arereduced out, and intrasubdomainconstraints are included in the secondlevel of the multilevel solver.

• We solved representativemodel structures problems (2 millionunknowns). This includes both solvingstatic problems and computing a fewof the lowest modes. We developed astrategy to determine missed modesand will include it in a future release ofPARPACK. We have developed thefunctionality to analyze floatingsubstructures in a prototype codeonly.

Publications

Refereed

Day, D. 1996. “A Basic Parallel SparseEigensolver for Structural Dynamics.”Paper presented to the SIAM NationalConference, Palo Alto, CA, November.

3504.070

Density-Functional Theoryfor Classical Fluids atComplex Interfaces

L. J. D. Frink, E. R. Lindgren, K. D.Devine, A. G. Salinger

The primary objectives of thisproject were to develop a code formodeling inhomogeneous fluid systemsin 2-D and 3-D geometries and todemonstrate the utility of the code.Sandia used the first two years toidentify and solve several test problemswith an initial 1-D code, develop thecomputational strategies for severaltypes of model systems, and implementan initial parallel 2-D/3-D capability.Final-year efforts focused on improvingthe algorithms to achieve up to one–twoorders-of-magnitude speed-up, applyingthe code to problems in 2-D with morecomplex surfaces than have ever beenstudied with a nonlocal density-func-tional theory (DFT), and cultivatingapplication areas including corrosion


(Accelerated Strategic ComputingInitiative [ASCI]), competitive adsorp-tion in zeolites, sensors, self-assembly,colloidal systems, surface forces/adhesion, and emerging threats/computational biology. As a result of thisproject, Sandia now has a uniquecapability for modeling inhomogeneousfluids for applications ranging fromprocessing of nanoscopically tailoredmaterials to materials aging to emergingthreats/biological warfare (BW).

In the first year of this project,accomplishments centered on devel-oping a 1-D code and applying thatcode to a variety of materials prob-lems. In year two, the applicationswork continued, but code develop-ment efforts shifted to a new 3-D code(called TRAMONTO), and we com-pleted an initial parallelization. In thefinal year, applications work focusedon systems that need a 2-D code. Wemade several improvements to thealgorithms to achieve very efficientparallel 2-D solves. In addition, wecompletely rewrote the previous year’sparallelization to improve memoryhandling and code scaling for 3-Dapplications. By the end of the year,focus had shifted to 3-D applications.These capabilities are having a greatimpact both inside and outside ofSandia.

While we initially developed a2-D/3-D parallel code, the outlook forthe code was uncertain because of thecomplexity of the needed Jacobian fill.To demonstrate a viable method, itwas therefore necessary to improvethe performance of the fill algorithm.We achieved this by implementingnonuniform meshes, coarsenedJacobians, and approximate Jacobians.The result was that the fill can now beperformed 10–100 times faster(depending on the particulars of theunderlying mesh) than was possiblewith the earlier algorithms. Theseimprovements provided immediateaccess to a wide range of 2-D prob-lems. Two systems previously studiedextensively as test cases were cylindri-cal polyelectrolytes in electrolyte

solutions, and wetting and self-assembly at chemically heterogeneous(striped) surfaces.

Even with the improved Jacobianfill routines, all but the simplest 3-Dapplications remained out of reach dueto a non-optimal initial parallelization.As a result, we rewrote theparallelization. The latest version ofthe code scales linearly with thenumber of processors, and real 3-Dapplications are within reach.

In addition to working onimproved algorithms for TRAMONTO,we also cultivated application areas forfuture work with this code. Thoseapplication areas of most interest toSandia include corrosion (ASCI),competitive adsorption in zeolites,sensors, self-assembly, colloidalsystems, surface forces/adhesion, andemerging threats/computationalbiology. The impact of this work isbeing felt outside as well as insideSandia. Inquiries from many sourceshave focused on these modelingcapabilities, including modeling gasadsorption, modeling disk driveperformance, modeling adsorption inrandom porous media, modelingdrying of porous materials, andmodeling ion-channel proteins. As aresult of this project, Sandia now has aunique capability for modelinginhomogeneous fluids for applicationsranging from processing ofnanoscopically tailored materials tomaterials aging to emerging threats/BW.

Copyright and licensing forTRAMONTO were begun by the end ofcalendar year 1998.

Publications

Refereed

Frink, L. J. D., and A. G. Salinger. 1998.“Wetting of a Chemically Heteroge-neous Surface.” J. Chem. Phys., submit-ted.

Frink, L. J. D., and F. van Swol. 1998. “ACommon Theoretical Basis for SurfaceForces Apparatus, Osmotic Stress, and

Beam Bending Measurements ofSurface Forces.” Colloids and Surf. A,submitted.

Frink, L. J. D., and F. van Swol. 1998.“Solvation Forces Between RoughSurfaces.” J. Chem. Phys. 108 (1 April):5588–5598.

Samuel, J., C. J. Brinker, L. J. D. Frink,and F. van Swol. 1998. “Direct Measure-ment of Solvation Forces in ComplexMicroporous Media: A New Character-ization Tool.” Langmuir 14 (22 April):2602–2605.

Other

Frink, L. J. D. 1997. “Capillary Conden-sation and Adhesive Pull-Off Forces.”Paper presented to the Annual FallMeeting of the American Institute ofChemical Engineers, Los Angeles, CA,20 November.

Frink, L. J. D., and A. G. Salinger. 1998.“Calculating Solvation Forces andAdsorption in Complex Geometrieswith a Finite Element–NonlocalDensity-Functional Theory.” Paperpresented to CIMTEC ’98, WorldCeramics Congress and Forum on NewMaterials, Florence, Italy, June.

Frink, L. J. D., and A. G. Salinger. 1998.“Solving Nonlocal Density-FunctionalTheories in Geometries WithoutConvenient Symmetries.” Paperpresented to the LIBLICE Conferenceon the Statistical Mechanics of Liquids,Zelzna Ruda, Czech Republic, 7–12June.

Frink, L. J. D., A. G. Salinger, and F. vanSwol. 1997. “Beyond DLVO Theory andthe Yukawa Potential for Simulation ofColloidal Systems.” Paper presented tothe Annual Fall Meeting of the Ameri-can Institute of Chemical Engineers,Los Angeles, CA, 18 November.

Frink, L. J. D., A. G. Salinger, and F. vanSwol. 1997. “Density-Functional Theoryfor Classical Fluids on Parallel Comput-ers.” Paper presented to the AnnualFall Meeting of the American Instituteof Chemical Engineers, Los Angeles,CA, 18 November.


3504.120

Fast and Easy Parallel I/O forEfficient ScientificComputing

J. E. Sturtevant, M. L. Barnaby, D. N.Sands, R. A. Haynes

The performance of input/output(I/O) subsystems on massively parallel(MP) computers lags the computationalpower of these machines. I/O includesdata transfer to and from disks, archivalstorage, and networks. New algorithmsand approaches to I/O are necessary tocompensate for the imbalance betweenI/O and computational performance. Inthis project, Sandia will develop newtools and algorithms that allow applica-tions programmers to use I/O resourceseasily and efficiently and will work withthe ALEGRA and PRONTO groups to testthese ideas in important Sandiaapplications on the Teraflop machine.Deliverables will include (1) an I/Oresearch platform on which newapplication interfaces, libraries, andalgorithms for I/O can be incorporatedand tested, (2) an I/O library with asimple, general-purpose interface forapplication programmers, (3) a higher-level I/O library for finite-element (FE)applications, and (4) optimal datalayouts for efficient data retrieval basedon common or user-specified accesspatterns.

We will focus on collective I/O,i.e., coordinated requests from manyprocessors, because of the increasedpotential for efficient use of disk andtape systems. Programs that require out-of-core computation or frequentcheckpointing should see significantperformance improvement due to lowerI/O overhead. Moreover, new I/Ocapabilities developed in this projectwill allow larger simulations to be run,reduce the computer time required forthese simulations, eliminate the long

file-recombination processor prior tovisualization, and reduce the program-ming time to develop new applications.In sum, the Accelerated StrategicComputing Initiative (ASCI), modelsimulation–based life-cycle engineering(MSBLCE), and warhead protectionprogram (WPP) codes will be able tosolve bigger problems than wouldotherwise be possible, and they will runfaster while doing so.

We progressed toward theultimate goal of having a scalableparallel I/O (PIO) library that simula-tion and visualization applications canuse to transfer massive amounts ofdata among memory, disks, and tapearchive. The research done by thisproject has affected both ASCI prob-lem-solving environment (PSE) andDisCom plans.

We established a solid softwareinfrastructure, delivering a usable,high-performance PIO library forSandia unstructured-grid FE applica-tions. We continue to improve the low-level collective disk I/O library thatsupports efficient transfers of locallypermutable data arrays with minimalbuffering requirements and the mid-level parallel data set (PDS) manage-ment library that supports collective,random access of primitive FE dataarrays.

Specifically, we accomplished thefollowing:

(1) Designed and implementedan additional library, PXI (ParalleleXodus Interface), to provide a higherlevel of abstraction for both simulationand visualization applications. Basedon our initial experience integratingPDS/PIO into simulation and visualiza-tion applications, we identified theneed for a higher level of abstraction.Applications using the eXodus II dataformat expected a high-level applica-tion programming interface (API) andthus can be more easily transitioned toPXI.

(2) Integrated the PIO library,PXI/PDS/PIO (Parallel eXodus Inter-face/Parallel Data Set/Parallel I/O) intoALEGRA and PRONTO. Initial observa-tions from ALEGRA using the currentparallel file system (PFS) on theTeraflop indicate at least a fourfoldspeedup in I/O.

(3) Adapted two visualizationpackages, MUSTAFA (a Sandia-specificAVS/Express project) and EnSight (acommercial visualization tool) to readthe new file format, PXI (PDS).

(4) Instrumented the PIO libraryto measure performance of the lowest-level I/O functions.

(5) Improved the PDS interfacebased on experience with PXI.

Publications

Refereed

Sturtevant, J., M. Christon, P. D.Heermann, and P. C. Chen. 1998. “PDS/PIO: Lightweight Libraries for Collec-tive Parallel I/O.” Proc. Supercomputing1998, accepted.

3504.130

Novel Load-Balancing forScalable, ParallelElectromagnetic and PlasmaPhysics Simulation Software

M. L. Kiefer, R. S. Coats, L. P. Mix, Jr., M.F. Pasik, D. J. Riley, D. B. Seidel, S. J.Plimpton

Electromagnetic particle-in-cell(EM-PIC) simulation techniques are usedto address many Sandia NationalSecurity (NS) areas and AcceleratedStrategic Computing Initiative (ASCI)applications. These include simulationof neutron generators, weapon responseto hostile x-ray environments, Z-pinch(x-ray) accelerators, radiography


systems for weapon primaries, and high-power microwave devices. EM-PICsimulates the time-response of EM fieldsand low-density plasmas in a self-consistent manner (the fields push theplasma, and the plasma self-currentmodifies the fields). We currently use theSandia QUICKSILVER/VOLMAX codesuite for these applications, but it doesnot yet have the scalability required toperform full system-level simulations onthousands of nodes as required for ASCIapplications. The chief obstacles areload-balancing the computations due tothe nonuniform, time-dependent densityof particles on the grid and the use ofdifferent numerical algorithms and celltypes in various grid regions. We willtest and implement novel methods toachieve a fully parallelized scalablecode and have devised two potentialcandidates. The first is a static methodthat divides the grid into many moresubdomains than nodes and assignsthem to nodes so that, on the average,each node has nearly equal amounts ofcomputation per time-step. The secondis a dynamic method where weightedsubdomains will migrate as neededbetween nodes to address the changingworkload due to particle motion. We willalso automate setup for parallelexecution as well as parallelizediagnostics.

Both QUICKSILVER and VOLMAXare now running. We implemented thefull static decomposition method inQUICKSILVER for both pure EM andEM-PIC plasma simulation usinghundreds of processors. This repre-sents a significant advancement overthe previous year’s accomplishment,where only a subset of QUICKSILVER’sfull capabilities was available for theparallel version. Our testing showedthat this version will work at the tera-scale level (thousands of processors),but difficulties in getting such simula-tions through the queues in a timelymanner have delayed performing

them. We believe this version ofQUICKSILVER is capable of EM and EM-PIC simulations well beyond any othersuch codes.

The QUICKSILVER preprocessorperforms static 3-D decompositions ofmultiple-block rectilinear grids intogeneral rectangular subdomains.Detailed studies of this decompositionscheme show that parallel efficiencyon the Red machine is acceptable forvery small subdomain sizes. Sizes asfew as 3000 for the sum of the cells andparticles work well. These resultsdemonstrate that over-partitioningtechniques (many more subdomainsthan nodes) will not fail because ofexcessive communication time. Testingalso showed that communicationoverhead is acceptable with eightpartitions per node on 64 nodes. Ournext step is to implement and test inQUICKSILVER a dynamic load-balanc-ing technique. This will extend thegeneral static method to a dynamicmethod that migrates subdomainswhen load imbalances appear.

We parallelized a significantportion of QUICKSILVER’s extensivediagnostic capabilities this year whileretaining our efficient data file format.This allows us to use our sophisticateddata analysis tools. Now the code canbe used for massively parallel (MP)production-level simulation andanalysis. This parallel file creationcapability uses Sandia’s parallel dataset/parallel input/output (PDS/PIO)library and has proven to be robustand easy to use.

Many spin-offs of this researchhave improved the general state ofQUICKSILVER. First, we discovered anew PIC data-handling method thatincreases computational speed bymaking better use of central processorunit (CPU) caches. Second, we foundthat as the subdomain size is reduced,we reach the point where data for anentire subdomain fits in the CPU

cache, resulting in a sharp increase inperformance. This occurs well beforethe subdomain size reaches the pointwhere communication overheadbegins to significantly reduce perfor-mance. Third, the new message-passing algorithms for repairing dataon the surface of each subdomain withdata from the interior of anothersubdomain have proven to date to bemore straightforward than those usedfor the shared-memory processing(SMP) version.

The unstructured grid portion ofthe VOLMAX code, where each nodehas exactly one subdomain, is nowparallelized for EM simulation, andhundreds of processors have beenused. We accomplished the griddecomposition into subdomains, usinggrids generated by the commercialI-DEAS software, using Sandia’sCHACO/NEMESIS tools. The decompo-sition itself is performed in a parallelmanner and is quite efficient. We willsoon parallelize VOLMAX for hybridgrids (where portions of the grid areunstructured, others are rectilinear,and different time-step values are usedin each type) for EM simulation withone subdomain per node.

In both QUICKSILVER andVOLMAX, extensive tests revealedsubtle algorithmic sensitivities toparallel connection schemes for bothrectilinear-grid particle-related dataand unstructured-grid EM field data.We are currently investigating theseproblems. These sensitivities cause thesimulation to become unstable. It isthought that the cause may be a smalldifference, possibly only the leastsignificant difference, in data that areduplicated on different subdomains.We think that minor changes to theconnection schemes will eliminate theproblem; however, a complete under-standing of these sensitivities isrequired.


3504.140

Parallel ComputationalChemistry Using Constraints

T. D. Plantenga, C. F. Melius, S. J.Plimpton

Accurate computer estimation ofmaterial properties requires solvingforce-field equations for systems of up toa million covalently connected atoms.Covalent bonds are usually modeled asstiff harmonic potentials in the forcefields. Our research shows they are theprimary source of numerical difficultiesin the computation of structures withminimum potential energy.

This project will develop ad-vanced optimization algorithms for fast,robust computation of the local energyminima of large molecules. We willimplement and test algorithms in threeSandia computational chemistry codes:LAMMPS (Large-Scale Atomic/MolecularMassively Parallel Simulator), CCEMD(Center for Computational EngineeringMolecular Dynamics), and DEMoS(Distributed Extensible MolecularSimulation). Two of these, LAMMPS andDEMoS, require that the algorithmsexploit distributed computing environ-ments. An implicit Hessian methodutilizing modified conjugate gradientwill provide the basis for an uncon-strained algorithm. A novel constrainedoptimization approach will aim toeliminate numerical ill-conditioning bysubstituting quadratic distance con-straints for the stiff harmonic potentials.This technique is known to speed upmolecular dynamics (MD) calculationsby a factor of three, but has never beenapplied on a large scale to calculateenergy minima.

We succeeded in adding minimi-zation algorithms to LAMMPS, CCEMD,and DEMoS. The algorithms havealready proved useful in AcceleratedStrategic Computing Initiative (ASCI)work on estimating O-ring diffusioncoefficients.

We implemented minimizationalgorithms and are already using themin LAMMPS to estimate O-ring diffusioncoefficients. The research effort also

expanded beyond original goals topursue promising new ideas.

We upgraded the unconstrainedimplicit Hessian conjugate gradient–based algorithm to support version 4.0of LAMMPS. We recast the samealgorithm in object-oriented Java codefor incorporation in the new DEMoSproject. In collaboration with theOptimization Technology Center (OTC)of Northwestern University andArgonne National Laboratory, wetested a new preconditioner based onlimited-memory BFGS concepts withthe unconstrained algorithm. Thepreconditioner performed well, butneeds more fine-tuning.

We implemented the Newton–based constrained minimizationalgorithm and tested it with the Sandiacode CCEMD. We significantly en-hanced performance by choosingconstraints in a preprocessing stepbased on QR factorizations, and byutilizing sparse Cholesky factorizationsduring minimization. We had hopedthat the constrained algorithm couldbe converted to a massively parallel(MP) format for integration intoLAMMPS. We distributed vector andmatrix objects and replaced the sparseCholesky factorization with the SandiaAZTEC solver code. However, distribu-tion of the constraints did not matchthe distribution of atoms chosen byLAMMPS, thus creating high communi-cations costs on the Teraflop machine.Investigations with the preprocessingformula demonstrated that theconstraint set cannot be alteredwithout causing dramatic ill-condition-ing. It is hoped that the more generaldistributed computing approach takenby DEMoS will allow unmatched atomand constraint distributions tocommunicate without high overheadcosts.

We also tested remote optimiza-tion, in which we executed the compu-tational chemistry and optimizationalgorithm codes on separate networks,linked only by occasional data trans-fers. This computing model providessecurity partitioning and some faulttolerance.

Publications

Other

Plantenga, T. D. 1998. “Fast EnergyMinimization of Large Polymers UsingConstrained Optimization.” SandiaTechnical Report SAND98-8251(October). Sandia National Laborato-ries, Albuquerque, NM.

Plantenga, T. D. 1998. “MolecularEnergy Minimization in Parallel UsingConstraints.” Paper presented to theAmerican Mathematics Society FallWestern Sectional Meeting, Albuquer-que, NM, November.

Plantenga, T. D. 1998. “Parallel Uncon-strained Minimization of PotentialEnergy in LAMMPS.” Sandia TechnicalReport SAND98-8201 (October). SandiaNational Laboratories, Livermore, CA.

3504.160

Massively Parallel Ab InitioValidation for ASCI MaterialsAging

C. F. Melius, C. L. Janssen, C. H. Tong

Sandia is undergoing a revolution-ary transition from being a lab based onexperimental testing to a lab based onpredictive computational modeling. Acentral part of the Accelerated StrategicComputing Initiative (ASCI) is a detailedmodel–based understanding of the agingof weapon components. Such anunderstanding will require the simula-tion of molecular systems larger thanhave ever been studied at accuraciesbeyond the state-of-the-art, even forsmall chemicals. Currently, large-scaleab initio quantum chemistry (QC)simulations are possible using themassively parallel (MP) Hartree-Fock(HF) and density-functional methodsdeveloped at Sandia. Unfortunately,these workhorse QC techniques do nothave predictive accuracy for many of thechemical species formed in the aging ofpolymers and energetic materials (e.g.,the peroxyl radicals formed in the agingof PETN). Chemically accurate predic-


tions are possible with these methods ifthey are calibrated and if systematiccorrections are developed that dependon the chemical system being modeled.Historically, these computer simulationswere accurate QC methods, such ascoupled-cluster theory, which approachthe exact result with increased computa-tional effort. The goal of the project is toprovide methods for calibrating theworkhorse simulation methods for theASCI project and other Sandia programsby developing MP versions of moreaccurate, highly electron-correlatedquantum chemical methods.

Also during this project, we willapply these parallel methods to severalproblems related to the chemical agingof high-energy weapon components.These benchmark calibrations willconstitute some of the largest highlycorrelated QC calculations ever per-formed and will take full advantage ofteraflop-scale parallel computing.

We implemented a program forthe parallel computation of coupled-cluster singles and doubles withperturbative triples correction(CCSD[T]) in the C++ language. This isthe first CCSD(T) program that uses adistributed data representation for allof the large coupled-cluster intermedi-ates. We validated the program with aseries of small molecules, including thePETN fragment CH3ONO2. In thecourse of our work, we discovered aserious flaw in the size-scaling of allcurrently used coupled-clusterdiagnostics that causes the value ofthe diagnostics to be meaningless formost large chemical systems. Weproposed an alternative diagnostic forthe closed-shell case that shows thecorrect size-scaling, and demonstratedthat the value of the diagnostic isindeed correlated with the accuracy ofphysical properties. We collaboratedwith the University of California–Berkeley to develop local-correlationmethods. We developed the atoms-in-molecules (AIM) approach to local-correlation, applied it to the second-order Möller-Plesset framework, andcarefully examined its convergence tothe exact nonlocal methods.

3504.190

Integrated Quantum/Classical Modeling ofHydrogenic Materials

J. G. Curro, R. M. Fye, F. B. Van Swol

This project concerns the model-ing of quantum fluids with the pathintegral (PI) formalism. In the PIapproach, Sandia will map quantumparticles onto classical ring polymersthat consist of beads connected byharmonic springs. The key observationis that ring polymers can be modeled bymolecular simulation methods as well asby integral equation approaches, both ofwhich are actively pursued in this effort.The molecular simulation methods focushydrogen adsorption at single substrates,graphite slit pores, and nanotubes. Weare also studying quantum sieving oftritium from a mixture of hydrogen. Theintegral equation methods consist of aself-consistent field theoretic extensionof Polymer Reference Interaction SiteModel (PRISM) theory to ring polymerfluids.

(1) Single surfaces. We madeseveral comparisons between simula-tion and experiments for the adsorp-tion of hydrogen isotopes onto agraphite substrate.

(2) Confined fluids. We performeda detailed study of hydrogen isotopesadsorbed into porous materials andfound that quantum effects lead to asuppression of the capillary condensa-tion transition.

(3) Nanotubes. We explored thehydrogen storage potential ofnanotubes. In particular, we quantified

the storage capabilities for hydrogenin porous graphite (using slit pores)and a variety of single-wallednanotubules (SWNTs). We can improvethe latter’s storage capability byexploiting the outer surface, as inarrays of SWNTs.

(4) We performed simulations onquantum sieving of tritium fromtritium/hydrogen mixtures. Prelimi-nary results confirm the existence ofquantum sieving, whereby quantumeffects can preclude the adsorption ofthe lighter isotopes.

(5) PRISM calculations. We wrotea computer code to treat polymerrings with PRISM theory. The programuses a self-consistent solvationpotential to describe the correlationsbetween different rings.

Publications

Refereed

Wang, Q., and J. K. Johnson. 1998.“Adsorption of Hydrogen in GraphiteSlit Pores.” Internat. J. Thermophys.,accepted.

Wang, Q., and J. K. Johnson. 1998.“Hydrogen Adsorption on Graphiteand in Carbon Slit Pores from PathIntegral Simulations.” Molecular Phys.,accepted.

Wang, Q., J. K. Johnson, and J. Q.Broughton. 1998. “Path Integral GrandCanonical Monte Carlo.” J. Chem. Phys.107 (1 January): 5108.

Yethiraj, A. 1997. “ConformationalProperties and Static Structure Factorof Polyelectrolyte Solutions.” Phys.Rev. Lett. 78 (1 January): 3789.


3504.170

Computational Methods forCoupling Microstructural andMicromechanical MaterialsResponse Simulations

E. A. Holm, G. A. Knorovsky, C. C.Battaile, V. R. Vedula, M. D. Rintoul, T.E. Buchheit, R. M. Fye, G. W. Wellman,M. K. Neilsen, S. J. Glass, H. E. Fang

Computational materials simula-tions have traditionally focused onindividual phenomena: grain growth,crack propagation, plastic flow, etc.However, real materials behavior resultsfrom a complex interplay betweenphenomena. Sandia will exploremethods for coupling mesoscalesimulations of microstructural evolutionand micromechanical response. In onecase, we will dynamically couplemassively parallel (MP) simulations forgrain evolution and microcracking inbrittle materials. In the other, MP codesfor domain coarsening and plasticdeformation will be iteratively linked.This project will provide the firstcomparison of two promising ways tocouple mesoscale computer codes. Wewill extend Sandia’s MP PARGRAIN codeto simulate microstructural evolution. Toovercome the computational limitationsof resolving crack-tip singularities, wetake a three-tiered risk approach tofracture modeling. Initially, PARGRAINwill couple with the parametric GLADmodel; later, with a more costly finite-element (FE) model with death ele-ments; and finally, with a newly devel-oped Element-Free Galerkin (EFG)model. Plastic flow is amenable to aconventional FE modeling approach. Wewill extend the constitutive relationsused in the JAS3D–based crystalplasticity model to incorporate theappropriate flow mechanisms. Couplingmicrostructure and mechanics codes willrequire time synchronization, meshmatching, and information-passingalgorithms appropriate to each case. Wewill experimentally validate the com-puter simulations on stockpile materials.We will study microcracking in brittlematerials in the context of alumina usedin stronglinks. We will study plasticdeformation response in a silver-copper

(Ag-Cu) eutectic braze alloy used inweapon components. This project willachieve the first experimentally vali-dated model for plastic deformation andfracture in realistic, evolving microstruc-tures. Moreover, this project providesthe first full spatial and dynamicintegration of computational models forcoupled materials response phenomena.The mesh linkage and time-stepsynchronization techniques developedhere will have applications in varioussimulation methods and will supportSandia’s stockpile stewardship mission.

We extended the Monte CarloPotts model (MCPM) to include a newstrain-dependent coarsening modeland a mesh-independent sphere-of-influence local energy calculation. Wedeveloped a new, order-of-magnitude-faster Potts algorithm and imple-mented it in PARGRAIN. This algorithmallows more straightforward extensionto important physical problems. Wedeveloped, tested, and parallelized thefirst fully 3-D GLAD model. We directlycoupled the 2-D MP GLAD code to 2-DPARGRAIN and resolved meshing, time-step matching, data transfer, andphysical issues. PARGRAIN/MP GLAD isthe first and only simulation codecapable of modeling simultaneousmicrostructural evolution and inter-and transgranular cracking underthermomechanical deformations.Results show complex dependenciesbetween grain growth and fracture. Weextended EFG 2-D to simulatemicrocracking in ceramic materialsdue to residual thermal stresses and toperform tensile tests of microcrackedpolycrystals. We incorporated animproved work-hardening law into theJAS3D polycrystalline plasticity model.We successfully modeled a singlepolycrystalline Cu fatigue loop, solidsolution-strengthened Cu and Agalloys, and a two-phase microstruc-ture. We implemented the first coupledPARGRAIN/JAS3D simulations using adata-passing approach. Computationalissues addressed include meshmatching, update frequency, andelement state adjustment when aboundary moves through. PARGRAIN/JAS3D is the first model that allowsmicrostructural-scale resolution ofgrain evolution and stress state.

Preliminary results for a short tensilehold test of pure Cu show previouslyunobserved features, including strain-inhibited grain growth. We overcamelogistical difficulties in the ceramicexperiments. We quantified growth andcoarsening parameters in the Ag-Cualloys. We performed fatigue tests andnanoindentation studies that led to anew experimental approach forstudying the microstructure/micromechanics relationship.

Publications

Refereed

Battaile, C. C., and E. A. Holm. 1998.“Evolution of 2-D Potts Model GrainMicrostructures from an Initial HillertSize Distribution.” Proc. Internat. Conf.on Grain Growth, accepted.

Buchheit, T. E., G. W. Wellman, M. K.Neilsen, and R. J. Bourcier. 1997. “3-DDeformation Simulations of Polycrys-talline FCC Metals.” Paper presented tothe 2nd Biennial Tri-Laboratory Engi-neering Conference on Modeling andSimulation, Santa Fe, NM, November.

Fang, H. E. 1997. “A Multilevel Compu-tational Model for PredictingThermomechanical Fatigue in SolderJoints.” Paper presented to SC ’97, SanJose, CA, November.

Fang, H. E. 1998. “MicrostructuralEvolution and Mesoscale Fracture.”Paper presented to the ER/SSI Materi-als Group Meeting, Oak Ridge, TN,May.

Fang, H. E. 1998. “Multilevel Modelingof Thermomechanical Fatigue in SolderJoints.” Paper presented to the ASCI PIMeeting, Los Alamos, NM, July.

Fang, H. E. 1998. “ThermomechanicalFatigue of Solder Joints.” Paperpresented to the Center 9200 ExternalReview, Santa Fe, NM, June.

Fang, H. E., V. L. Porter, R. M. Fye, andE. A. Holm. 1997. “Multi-Level Modelingof Thermomechanical Fatigue in SolderJoints.” Paper presented to the 2nd

Biennial Tri-Laboratory EngineeringConference on Modeling and Simula-tion, Los Alamos, NM, November.

Fang, H. E., V. L. Porter, R. M. Fye, andE. A. Holm. 1997. “Simulation of


Thermomechanical Fatigue in SolderJoints.” Paper presented to the 5th

Joint Conference on ComputationalMathematics, Albuquerque, NM,September.

Fye, R. M. 1998. “Fast Algorithm forPotts Model Simulations of GrainGrowth.” Paper presented to the DOE/AMS Workshop on MathematicalAspects of Materials Science Modeling,Gatlinburg, TN, April.

Fye, R. M. 1998. “Fast Algorithm forSimulating Grain Growth Using thePotts Model.” Paper presented to the1998 Conference on ComputationalPhysics, Granada, Spain, September.

Holm, E. A. 1997. “Applications ofMesoscale Materials Models atSandia.” Paper presented to theCaterpillar Research Group Seminar,Peoria, IL, September.

Holm, E. A. 1997. “Computers inMaterials Science: Processing, Perfor-mance, and Reliability Modeling.”Paper presented to the ASM Interna-tional Peoria Chapter Meeting, Peoria,IL, September.

Holm, E. A. 1998. “Modeling of Micro-structure-Property Relationships.”Paper presented to the GordonResearch Conference on PhysicalMetallurgy, Holderness, NH, June.

Holm, E. A. 1998. “The Surface Forma-tion Energy for Intergranular Fracturein Two-Dimensional Polycrystal.” J.Amer. Ceram. Soc. 81 (March): 455–459.

Holm, E. A., C. C. Battaile, M. D.Rintoul, and H. E. Fang. 1998. “Applica-tions of Grain Growth Modeling.”Paper presented to the 3rd Interna-tional Conference on Grain Growth,Pittsburgh, PA, June.

Rollett, A. D., W. W. Mullins, M. D.Rintoul, and E. A. Holm. 1998. “TheLink Between Kinetics and Configura-tional Statistics in Two-DimensionalGrain Growth: Comparison of Theoryand Simulation.” Proc. Internat. Conf. onGrain Growth, accepted.

Tikare, V., and E. A. Holm. 1998.“Simulation of Grain Growth and PoreMigration in a Thermal Gradient.” J.Amer. Ceram. Soc. 81 (March): 480–484.

3504.250

From Atom-Picoseconds toCentimeter-Years inSimulation and Experiment

J. C. Hamilton, M. F. Horstemeyer, J. M.Faulon

The understanding of agingphenomena is a critical aspect ofstockpile stewardship. Accelerated agingtests and examinations of stockpilecomponents play an important role, butboth have their limitations. Acceleratedaging tests at elevated temperaturesskew the relative probabilities ofvarious reactions. Examination ofstockpile components provides a limiteddatabase and tends to leave us in areactive rather than proactive position;we may learn about a problem onlywhen it is almost too late to do anythingabout it. Consequently, it is a vital partof stockpile stewardship to developsimulation techniques that are accurateand valid over much greater time andlength scales than those presentlyavailable. Most importantly the simula-tion techniques should be tested byexperiment at various length and timescales so they can be validated andimproved.

In the past year Sandia maderapid progress toward this goal. Oursuccess is due in part to highly produc-tive collaborations with the originatorsof a state-of-the-art first-principles code(VASP) and of the hypermoleculardynamics (HMD) method. Both of thesetechniques are likely to become impor-tant to Sandia modeling efforts. We alsodeveloped a massively parallel (MP)transition state theory (TST) code tocalculate hopping rates of penetrantmolecules in microporous media. We

will use this code for studies of zeolitesused as weapons desiccants.

(1) Sandia now has a highlyefficient MP first-principles code(VASP) incorporating the chain-of-states method for finding transitionstates. As part of this project, weinstalled, tested, and corrected thechain-of-states methods in VASP incollaboration with a colleague inVienna, Austria. VASP and the chain-of-states method are now fully integratedin a locally developed graphical userinterface (GUI) that allows a number ofSandia users to run VASP on multipleprocessor computer clusters at Sandia.

(2) Sandia now has a preliminaryversion of a code that performsparallel-replica variable-boost HMD.We demonstrated that this code canperform HMD even in the presence ofdramatically varying barrier heights.Dramatically varying barrier heightswill exist in most physical systems, sothis is an important result. This code isrunning in a developmental mode.

(3) We completed an efficientparallel code that identifies cavities inpolymer samples and calculatestransition rates between cavities. Fortests on simple cubic lattices, the codecorrectly identifies interstitial cavities,evaluates surface and volume inte-grals, and calculates intercavityhopping rates. In addition, we initiateda study of multicomponent diffusion inzeolites using TST.

(4) We performed calculations ofplanar simple shear for single-crystalnickel slabs with two orientationsranging in size from 46 to 9546 atoms.We plotted the simulated yield stressas a function of the surface-to-volumeratio and showed a definite correla-tion.


3504.180

An Investigation of WaveletBases for Multiscale, Grid–Based Simulation

M. A. Christon, D. W. Roach, S. P. Burns,D. E. Womble, T. E. Voth, R. S. Baty

The primary objective for thisproject is to establish a rigorousfoundation for grid–based hierarchical/wavelet simulation methods based onnumerical performance, computationalefficiency, parallelism, and the ability toexploit the hierarchical adaptive natureof wavelets. Wavelets are a newmathematical tool that dissects data,functions, and differential operators intocomponents of different frequency andwave number with a resolution matchedto the scale of each component. Waveletbases constitute a significant shift fromtraditional grid–based simulationmethods because the multiresolutioncharacter of wavelets enables thedevelopment of hierarchical solutions—a critical requirement for simulation–based design. Compactly supportedwavelets are localized in space,permitting the solution to be refinedwithout local or global remeshing toresolve regions of high gradients andwithout causing overshoot phenomena(ringing) in adjacent regions where thesolution is smooth. In addition, prelimi-nary studies indicated that waveletformulations can deliver spatialconvergence rates superior to finite-element (FE) and finite-difference (FD)methods. This effort seeks to develop arigorous technical framework for theevaluation and application of waveletbases to the solution of wave propaga-tion, advection, and diffusion problems.These physical processes are character-istic of complicated problems such asturbulent flow where the solutionaccuracy and computational require-ments depend on the numerical errors(e.g., numerical dispersion) associatedwith the computational method. Thealgorithms developed as a result of thisresearch will find direct application inmultiple Accelerated Strategic Comput-ing Initiative (ASCI) codes in addition to

wave propagation for problems thatdemand accurate far-field solutions suchas counterproliferation and environmen-tal characterization.

Research activities this yearfocused on the four areas associatedwith the primary project milestones:performing 1-D computational experi-ments and numerical analyses ofwavelet–based formulations, down-selecting the most successful formula-tions, and extending the work to twospatial dimensions. One of the primaryconsiderations in the down-selectionprocess was the ability to directly usewavelets in a solution strategy forhyperbolic, parabolic, and ellipticpartial differential equations (PDEs).The down-selection process relieddirectly on experiences with theDonovan-Geronimo-Hardin-Massopust(DGHM) multiwavelets in the contextof a Galerkin FE framework. Numericalanalysis determined that the DGHMwavelets yield an FE that has the costof a quadratic FE with the convergencerate of a linear FE and inferior disper-sive behavior for hyperbolic problems.However, work with the DGHM elementled to the conclusion that the strictorthogonality imposed for classicalwavelets, although popular in themathematics community, is neitherrequired nor desirable for an efficientmultiscale basis and, in fact, led to thedevelopment of a hierarchical basisthat is orthogonal in the energy normfor elliptic PDEs. This is consistentwith other research in the field wherestrict orthogonality has been relaxedin favor of bases where bi-orthogonal-ity and semi-orthogonality are im-posed. This result led to the develop-ment of the multiscale FE basis thatrelies on a coarse-grid linear FE andinjects multiscale degrees-of-freedomas dictated by the solution. A nodalchange-of-basis in the multiscaleelement yields condition numbers thatare independent of mesh resolution inone dimension, and scale approxi-mately as the mesh resolution inmultidimensions. Although themultiscale element is attractive forelliptic problems, we also selected thereproducing kernel (RK) method for

further investigation. The numericalanalysis demonstrated that reproduc-ing kernel particle method (RKPM)delivers excellent dispersive proper-ties for hyperbolic problems for theentire discrete spectrum representableby a grid or particle distribution. Inaddition, RKPM provides a naturalframework for multiscale decomposi-tion of discrete fields according to aprescribed scale and can make use ofpre-wavelets for adaptive computa-tions. RKPM is based on a flexiblespace-frequency window function thatresults in spatial filters compatiblewith commutative filtering operationsfor large-eddy simulation (LES). Inaddition, we demonstrated RKPM to beeffective for large-deformationLagrangian computations whereextreme mesh distortions lead topremature termination using tradi-tional methods. At this point, we arebeginning to apply both the multiscaleelement and RKPM to applicationsranging from thermal transport withphase transformation to LES ofturbulent flow fields.

Publications

Refereed

Christon, M. A., and T. E. Voth. 1998.“Results of von Neumann Analyses forReproducing Kernel Semi-Discretizations.” Internat. J. Numer.Meth. in Engin. (special issue), ac-cepted.

Christon, M. A., D. W. Roach, and T. E.Voth. 1998. “The Numerical Perfor-mance of Wavelets for PDEs.” Computa-tional Mechanics (special issue), inpress.

Roach, D. W., and D. Hardin. 1998.“Semi-Orthogonal Wavelets for EllipticVariational Problems.” Proc. Internat.Wavelets Conf.—Wavelets andMultiscale Meth. (Morocco, Tangier, 13–17 April).

Voth, T. E., M. A. Christon, and S. P.Burns. 1998. “Truncation and Disper-sive Errors Associated with Reproduc-ing Kernel Methods.” Computer Meth.in Appl. Mechanics and Engin., in press.


Other

Christon, M. A., D. W. Roach, and T. E.Voth. 1998. “The Numerical Perfor-mance of Wavelets and ReproducingKernels for PDEs.” Proc. Internat. Conf.on Computational Engin. Sci. 1 (Atlanta,GA, 6–9 October): 29–34.

Christon, M. A., R. S. Baty, S. P. Burns,D. W. Roach, T. G. Trucano, T. E. Voth,J. R. Weatherby, and D. Womble. 1998.“An Investigation of Wavelet Bases forGrid–Based Multiscale Simulations—Final Report.” Sandia Technical ReportSAND98-2456 (November). SandiaNational Laboratories, Albuquerque,NM.

Roach, D. W., M. A. Christon, D.Womble, T. E. Voth, S. P. Burns, R. S.Baty, D. Hardin, and P. Massopust.1998. “Semi-Orthogonal Wavelets forElliptic Variational Problems.” Paperpresented to the University of NewMexico Colloquium, Albuquerque, NM,24 April.

Roach, D. W., P. Massopust, M. A.Christon, and D. Womble. 1998. “AWavelet-Galerkin Multilevel Methodwith Level Independent Convergenceand No Preconditioning.” Paperpresented to the 9th InternationalConference on Approximation Theory,Nashville, TN, 3–6 January.

Voth, T. E., and M. A. Christon. 1998.“Results of von Neumann Analyses forReproducing Kernel Semi-Discretizations.” Proc. 4th WorldCongress on Computational MechanicsCDROM (Buenos Aires, Argentina, 29June–2 July).

3504.210

The Next Generation ofTeraflop Density-FunctionalElectronic Structure Codes

M. P. Sears, K. Leung, N. A. Modine, S. J.Plimpton, E. B. Stechel, P. A. Schultz, A.F. Wright

Sandia will develop a next-generation massively parallel (MP)electronic structure code, going wellbeyond Sandia’s current capabilities

with a focus on large systems andmaking direct connections with experi-mental spectroscopic observables. First-principles methods based on density-functional theory (DFT) offer awell-developed methodology for such acode. Experimental observables such asvibrational, optical, and electronspectroscopies are amenable to calcula-tion by linear response theory withinDFT. A competitive next-generation codemust scale linearly with system size (forboth energy/force and linear responsecalculations), must have an efficient MPimplementation, and must be thoroughlytested. We plan to develop a parallellinear response code that is independentof representation that accuratelycalculates second and third derivativesof the energy with respect to relativelyarbitrary perturbations. We plan tocreate a linear scaling serial version ofour linear combination of atomicorbitals (LCAO) code. We plan also tocombine a real-space variable gridmethod with our own innovative linearscaling algorithms, testing the resultingcode against existing codes and againstexperiment. The result will be a produc-tion tool useful for a wide variety ofmaterials research applications and willkeep Sandia in the forefront of this area.

Work is proceeding simulta-neously on several fronts: (1) linearresponse (second- and third-orderperturbation theory) to appliedperturbations ultimately with analgorithm that scales as Order N, (2)solution for the electronic structure ina curvilinear (variable grid in realspace, regular grid in curvilinearspace) coordinate system, includingnew ways to solve for the optimumcoordinate system, (3) the determina-tion of advantages and disadvantagesof various linear scaling algorithms inthe literature, including variationalGreen’s function approaches, (4)solution for the electronic structurenumerically on a fully real-space grid(no fast Fourier transforms [FFTs]),and (5) development of a linear scalingversion of LCAO-LDA (local densityapproximation) serial code. Our mostsignificant accomplishments this yearinvolve the linear response. We have a

fully operational variational linearresponse code that can calculate thefull phonon spectrum of a solid as wellas the dielectric response. When usedin conjunction with occupied station-ary states, this new algorithm, likeothers, scales as N3 for each perturba-tion, and therefore as N4 for vibra-tional modes. However, our newalgorithm is invariant to linear trans-formations and therefore not onlyworks with localized nonstationaryoccupied states but also will scalelinearly. We also derived, coded, anddebugged an efficient method for third-order perturbation theory within thesame formalism. Further progress onthe variable grid includes showing thatthe Pulay-like forces vanish identicallyand that the basis-set-dependentchange in the energy with movingatoms is entirely due to the change inthe Hilbert space. This is undesirableand similar to basis-set-superpositionerror in LCAO calculations. We aredevising possibilities to eliminate thiserror.

Publications

Refereed

Leung, K., and E. B. Stechel. 1998.“Occupied Subspace Invariant LinearResponse.” Paper presented to theAmerican Physical Society Meeting,Los Angeles, CA, March.

Stechel, E. B. 1997. “Linear Scaling,Linear Response and Distorted Grids inDensity-Functional Algorithms.” Paperpresented to the 213th AmericanChemical Society National Meeting,San Francisco, CA, 10 April.

Stechel, E. B. 1998. “Occupied Sub-space Invariant Variational Kohn-ShamDFT Through Third Derivatives (LinearResponse).” Paper presented to theCECAM Workshop: Local OrbitalMethods for Large-Scale AtomisticSimulations, Lyon, France, 22–25 July.

Stechel, E. B. 1998. “Occupied Sub-space Invariant Variational Kohn-ShamDFT Through Second Derivatives(Linear Response).” Paper presentedto the Workshop on Materials Theory,Davis, CA, 20–22 March.


3504.220

Methodology forCharacterizing Modeling andDiscretization Uncertaintiesin Computational Simulation

K. F. Alvin, K. V. Diegert, W. L.Oberkampf, B. M. Rutherford

To meet the goals of the scientifi-cally–based stockpile stewardshipprogram, significant confidence must bebuilt into a variety of numerical simula-tions. The goal of these simulations is toaccurately characterize the response ofcomplete systems with high-fidelity, 3-D,unsteady, coupled physics, together withuncertainty bounds on the responses.Quantifying uncertainties in computa-tional physics–based simulations is alsocritical to verification and validation ofthese simulations; without uncertaintyquantification, validation is highlysubjective. Nondeterministic methodsseek to quantify response uncertaintiesby propagating uncertainties due tostochastic inputs and variability oruncertainty in geometric, constitutive,and manufacturing parameters throughthe computational simulation. Thereremains a pressing need, however, toaddress the question of whether theproper physics have been modeled, bothmathematically and numerically. Theobjective of this research is to developmethods to quantitatively estimate theerrors or uncertainties due to themathematical form of the partialdifferential equations (PDEs) and errorsdue to the discretization of the equa-tions. Thus, this work complements, butis distinct from, nondeterministicmethods for numerical simulations.

Sandia is developing a methodol-ogy for characterizing the effects ofmodeling on computational simulation.This methodology is intended to apply inall numerical simulations of continuummechanics, assuming the mathematicalformulation of the physical model is

given by PDEs that are solved bydiscretization methods. The researcheffort focuses on three strategies forcharacterizing computational simulationerrors and uncertainties: (1) identifica-tion of error sources and interactions,(2) parameterization of the modelstructure, and (3) methods for evaluat-ing model uncertainty and its contribu-tion to global uncertainty. We will studytwo application areas, evolving fromlinear problems dominated by physicalmodeling considerations to nonlinearproblems dominated by numericaldiscretization errors. The methodologywill be applicable to applications beingdeveloped for the Accelerated StrategicComputing Initiative (ASCI), as well asother computational mechanics disci-plines.

We developed a methodology forcombining discretization error estima-tion with propagation of continuousparameter variabilities (i.e.,nondeterministic analysis). Thistechnique involves estimating theparameters of a response surface thatpredicts the analysis output over arange of parameter values. Thisresponse surface is extended toinclude mesh spacing as a parameter.We performed code analyses withvariations in both the uncertaincontinuous parameters of the modeland the characteristic mesh length.The resulting response surface couldthen be used to propagate parameteruncertainties while also identifying thediscretization error. As part of thiswork, we developed and tested asimple experiment design for combin-ing discretization error and parametervariabilities. We also worked withresearchers at the University ofWisconsin to implement a meta-modeling approach with discretequalitative model form parameters. Weidentified a framework for combiningmodel forms with inconsistent param-eter sets, which is important whenconsidering different model forms in a

model uncertainty analysis, and fordecomposing conceptual modelprobabilities into mathematical anddiscrete model probabilities. Weidentified limitations of samplingmethods for certain classes of stochas-tic differential equations, in particularwhere the statistics of the inputvariables are time-dependent. Finally,we made further progress on exampleproblems in flight dynamics andstructural dynamics.

Publications

Refereed

Alvin, K. F. 1998. “Treatment ofDiscretization Error inNondeterministic Analysis.” 1999 AIAAForum on Non-Deterministic Approaches(Washington, DC: AIAA), submitted.

Oberkampf, W. L., K. V. Diegert, K. F.Alvin, and B. M. Rutherford. 1998.“Variability, Uncertainty, and Error inComputational Simulation.” J. FluidsEngin. (New York), submitted.

Oberkampf, W. L., K. V. Diegert, K. F.Alvin, and B. M. Rutherford. 1998.“Variability, Uncertainty, and Error inComputational Simulation.” Proc. 1998ASME/AIAA Joint Thermophys. andHeat Trans. Conf. (Albuquerque, NM,15–18 June).

Oberkampf, W. L., S. M. DeLand, B. M.Rutherford, K. V. Diegert, and K. F.Alvin (U.S. Army). 1998. “A NewMethodology for the Estimation ofTotal Uncertainty in ComputationalSimulation.” 1999 AIAA Forum on Non-Deterministic Approaches (Washington,DC: AIAA), submitted.

Other

Alvin, K. F., W. L. Oberkampf, K. V.Diegert, and B. M. Rutherford. 1998.“Uncertainty Quantification in Compu-tational Structural Dynamics: A NewParadigm for Model Validation.” Proc.16th Internat. Modal Anal. Conf. II (SantaBarbara, CA, 2–5 February): 1191–1198.


3504.260

Emergent Behavior of LargeSwarms of Intelligent Agents

R. J. Pryor, J. E. Hurtado, B. L. Spletzer

This research focused on investi-gating and developing new methods ofanalyzing, predicting, and manipulatingthe emergent behavior of large swarmsof cooperating agents. Sandia developednew simulation and analysis tools andused existing particle physics simulationconcepts and codes. We also developedand documented a genetic algorithmlearning strategy. We used traditionalcontinuum and statistical mechanicsmethods to model a large swarm ofagents, and in other work we developeda distributed sensing and cooperativecontrol method that allows a swarm ofagents to share information as they eachlocate a set of targets. We developedpreliminary statistical nonlinear controlmethods to analyze the overall behaviorof a swarm of agents.

This year’s accomplishments canbe divided into four general categories:

(1) Co-evolutionary learningmethods. We developed a strategy forco-evolutionary learning and usedthese learning methods to developgenetic algorithm learning strategiesthat are specific to swarms of agents.We developed these learning strategieson Sandia’s massively parallel (MP)computer, the Paragon—an ideal test-bed for this phase of the research. Wealso developed a simulation code forinvestigating the resulting swarmbehavior.

(2) Applying continuum andstatistical mechanics methods tomodeling the overall behavior ofswarms of intelligent agents. We liftedthe theories behind traditional

continuum and statistical mechanicsand applied these methods to swarmsof intelligent agents. Using continuumand statistical mechanics analogies, wecan now design group behavior. Thatis, we accomplished obstacle andcollision avoidance by assigningrepulsive potential functions toobjects; we used attractive potentialfunctions to locate targets and mimicflocking or schooling patterns ofswarms of animals.

Using low-level attraction andrepulsion rules, we were able to createvery high-level behavior. In particular,we created some striking results bypaying close attention to surfacetension analogies. For example, wemanipulated a group of robots so theybehave very much like a fluid. Thegroup can cluster, move forward andtag targets, and even separate as theyencounter an obstacle, then regrouplater. We folded these ideas intoparticle physics simulation codes. Thisis a new application for particlephysics simulation concepts andcodes, and we have benefited from thefact that particle physics simulation isa mature subject that is well under-stood.

(3) A new approach to distributedsensing and cooperative control. Wedeveloped a novel approach todistributed sensing and cooperativecontrol that has its roots in functionminimization (i.e., traditional optimiza-tion). This approach works extremelywell for inexpensive function evalua-tions. We used nonlinear estimationand nonlinear adaptive controlmethods within the optimizationroutine to tune the update procedure.

Two remarkable features of thisapproach are that (a) one-dimensionalsearch methods are not employed, but

rather gradient information is inferredfrom neighboring agents, and (b) theupdate of all agents requires only onesensor (or function) evaluation peragent. This technique is ideally suitedfor controlling a swarm of autonomousrobots in search and surveillancetasks. In this application, distributedsensing is achieved through eachagent sampling and sharing hisinformation with others. Cooperativecontrol is accomplished by each agentusing his neighbors to approximate thefunction surface that leads to a control(or update) strategy for that particularagent. The true function is approxi-mated with a quadratic model, and weuse a least-squares routine to deter-mine the model coefficients that bestmatch the actual data. Each agent thenuses the quadratic model to generate aposition update.

(4) Nonlinear control design. Wedeveloped preliminary statisticalLyapunov control methods and alpha-beta coordination algorithms tomanipulate and analyze the overallbehavior of a swarm of agents. Theseare new approaches to choose thefocus for controlling the overallbehavior of a swarm of agents ratherthan the behavior of each individualagent. Using these methods we areable to statistically guarantee that theswarm of agents will conduct desiredgroup behaviors.

Publications

Refereed

Pryor, R. J. 1998. “Developing RoboticBehavior Using a Genetic ProgrammingModel.” Sandia Technical ReportSAND98-0074. Sandia National Labora-tories, Albuquerque, NM.


3504.230

Global Optimization forEngineering ScienceProblems

W. E. Hart, K. O. Hunter, J. S. Wagner, C.A. Phillips

A wide variety of scientific andengineering problems can be posed asoptimization problems in which thedesired solution to the problem corre-sponds to an optimal set of parametersfor an objective function that measures asolution’s quality. Sandia is developing alibrary of robust and efficient optimiza-tion algorithms that can be used to findglobally optimal solutions to complexoptimization problems. Our work willlead to a critical evaluation of standardglobal optimization algorithms (e.g.,genetic algorithms, simulated anneal-ing) as well as new, innovative methodsthat are inspired by our analysis. Thisanalysis will focus on a variety ofalgorithmic factors that fundamentallyaffect the practical application of thesemethods, including (1) the combinationof global sampling and local optimiza-tion, (2) termination rules that providepractical confidence guarantees, (3) theappropriate design of constrainedoptimization methods, (4) the effectiveuse of all function evaluations, and (5)the role of parallelism (for large-scaleoptimization problems). Our researchwill have immediate impact on threeapplication domains—problems relatingto scheduling, system design optimiza-tion, and chemical, biological, andwarfare (CBW) defense(counterproliferation). This effort willdevelop new expertise in globaloptimization techniques as well as buildon Sandia’s current expertise in parallelalgorithms.

We integrated eight new globaloptimization methods into stochasticglobal optimization (SGOPT) andevaluated their effectiveness on testproblems and real-world applications.We noted problems with currentimplementations of these methods onhigh-dimensional problems. We

extended the architecture of SGOPT toallow constrained and mixed-integeroptimization. We made a variety ofalgorithmic advances:

(1) Developed new hybridgenetic algorithms for continuoussearch spaces. Particularly, weanalyzed how the initial step size ofthe local search method needs to beinitialized to improve the efficiency ofthe entire optimization process.

(2) Extended a convergenceanalysis for evolutionary patternsearch to the most general case,thereby eliminating many artificialconstraints that were imposed byearlier versions of this analysis.

(3) Developed an empiricalanalysis for GAs optimizing noisyfunctions, which suggests weaknessesin current theoretical models.

(4) Developed a method foradapting the step size in GAs based ona novel hybridization with simulatedannealing.

We submitted one technicaladvance licensed for SGOPT 1.0 to aconsortium of companies.

Publications

Refereed

Eldred, M., and W. E. Hart. 1998.“Design and Implementation ofMultilevel Parallel Optimization on theIntel Teraflops.” Proc. AIAA Symp.Multidisciplinary Anal. and Optimiza-tion 1 (St Louis, MO, September).

Greenberg, D., W. Hart, and C. Phillips.1998. “Architecting Department-ScaleSimulation.” Algorithms for ParallelProcessing, accepted.

Hart, W. E. 1997. “A GeneralizedStationary Point Convergence Theoryfor Evolutionary Algorithms.” Proc.Internat. Conf. on Genetic Algorithms 1(Lansing, MI, 19–23 July): 127.

Hart, W. E. 1998. “On the Application ofEvolutionary Pattern Search Algo-rithms.” Proc. Evolutionary Program-ming VII 1 (San Diego, CA, 3 March):303.

Morris, C., et al. 1998. “Autodock 3.0:Automating Docking Using aLaramckian Genetic Algorithm and anEmpirical Binding Free-Energy Func-tion.” J. Comp. Chem., accepted.

Rosin, C. D., R. S. Halliday, W. E. Hart,and R. K. Belew. 1997. “A Comparisonof Global and Local Search Methods inDrug Docking.” Proc. Internat. Conf. onGenetic Algorithms 1 (Lansing, MI, 19–23 July): 221.

Trahan, M., J. Wagner, K. Stantz, P.Gray, and R. Robinett. 1998. “Swarmsof UAVs and Fighter Aircraft.” Proc. 2nd

Internat. Conf. on Nonlinear Problems inAviation and Aerospace, accepted.

Wagner, J. 1998. “ComputationallyIntelligent Algorithms for Design,Control, Analysis and Optimization.”Proc. AIPA 1998 Symp. 1 (TysonsCorner, VA, 17–18 March).

Other

Anderson, M., and W. Hart. 1998.“Optimizing Noisy Functions with anAdaptive GA.” In preparation.

Gray, P., C. Wehlburg, J. Wagner, G.Tisone, and H. Chan. 1998. “DenseMultispectral UV FluorescenceDetection of a Dilute Constituent in anOptically Dense Matrix.” Appl. Optics,submitted.

Gray, P., M. Trahan, and J. Wagner.1998. “Hybrid Simulated AnnealingEvolutionary Algorithms.” In prepara-tion.

Hart, W. E. 1998. “Methods for ParallelOptimization.” Presentation at OakRidge National Laboratory, Oak Ridge,TN, February.

Hart, W. E. 1997. “On the Convergenceof Evolutionary Pattern SearchAlgorithms.” Paper presented to theAMS Fall Western Section Meeting,Albuquerque, NM, November.

Hart, W. E. 1997. “On the Dynamics ofHybrid Genetic Algorithms that UseLocal Search.” Paper presented to theUC–San Diego, San Diego, CA, October.

Hart, W. E. 1997. “SGOPT: A C++Library of Global Optimization Meth-


ods.” Paper presented to the Interna-tional Symposium on MathematicalProgramming, Lausanne, Switzerland,29 August.

Hart, W. 1998. “Stochastic PatternSearch and Evolutionary Algorithms.”J. Artificial Intelligence and Mathemat-ics, submitted.

Stantz, K., M. Trahan, P. Gray, and J.Wagner. 1998. “Genetic Optimization ofRecurrent Neural Networks.” Inpreparation.

Wagner, J. 1998. “On Neural NetworkAnalysis of Mass Spectral Data.” Paperpresented to Los Alamos NationalLaboratory, Los Alamos, NM, May.

Wagner, J. 1998. “On Neural NetworkAnalysis of Mass Spectral Data.” Paperpresented to the ASMS Meeting,Orlando, FL, June.

Wagner, J. 1998. “Real-Time Analysis ofMass Spectral Data.” Paper presentedto the ASMS Meeting, Orlando, FL,June.

Wagner, J. 1997. “Status Report of theJoint Sandia–ERDEC Multispectral UVFluorescence Measurement AnalysisUsing Computationally IntelligentAlgorithms.” Proc. MASINT BiologicalDef. Sci. and Tech. Symp. 1 (PatrickAFB, FL, January).

Wagner, J. 1998. “Using GAs and NeuralNetworks to Analyze Mass Spec Data.”Paper presented to Oak Ridge NationalLaboratory, Oak Ridge, TN, May.

3504.240

Dynamic Simulation ofMechanical Systems withIntermittent Contacts

C. L. Lewis, R. A. Lafarge

Sandia is developing an efficientdynamic simulator to accurately predictprobabilistic distributions of motions forarbitrary numbers of bodies experienc-ing multiple applied forces and intermit-tent contacts. Current simulators employeither weak or computationally expen-sive contact models and frequently

cannot handle complex time-varyingcontacts. Our approach utilizes acompliant surface model. We areverifying our simulation results throughcomparison to physical data.

To prove the viability of ourcontact analysis and collision-detectionscheme, we integrated our software intoADAMS using the standard interfacelibrary developed by MechanicalDynamics, Inc. (MDI). We used themature user interface and advancednumerical integration tools in ADAMS todemonstrate the capabilities of ourcollision-detection software and contactmodel. MDI had implemented a con-straint–based contact model, but thendiscovered problems due to the rigidcontact approach. Consequently, theyremoved automatic contact modelingfrom the latest release.

The basic capability to automati-cally analyze intermittent contacts willnow enable the development of softwaremodules specific to Sandia applications.We are developing modules to predictthe statistical robustness of mechanismssuch as stronglinks, weapons, and smallsmart machines, as well as the robust-ness of the assembly, disassembly, andmaintenance procedures for thosemechanisms. Our simulation softwarewill provide force histories for criticaltasks and predict the success of inher-ently stochastic processes.

Our first task was to complete amodel for contact analysis. There weretwo ways for us to model contacts:hard or soft. In a hard contact model,the bodies are rigid; in a soft contactmodel, the bodies are compliant. Afterextensive research, we felt there weretoo many limitations to a hard contactapproach. To avoid this fundamentallimitation with the rigid-body formula-tion of contact dynamics and tocapture phenomena like wedging andpress fits, we chose the soft contactapproach with nonlinear lumpedelements.

To take advantage of MDI’s fullydeveloped computer-aided design(CAD) interface and robust numericalintegration codes, we integrated ourcollision-detection software andcontact analysis into ADAMS by using

callable ADAMS, the standard softwareinterface. With the implementation ofour contact model within ADAMS, wewere able to simulate intermittentcontacts between mechanismscomposed of non-convex bodiesrigidly jointed together.

By using Latin HypercubeSampling (LHS) for the generation ofrandom numbers, our implementationof the design of experiment (DOE)option should be significantly fasterthan that currently available. We aredeveloping a statistical analysispackage based on the LHS and ouradvanced simulation capabilities. Thispackage requires that we modify astandard input file to identify therandom variables. Using the modifiedinput file, we created multiple fileswith variations in the random param-eters. We then executed the individualfiles to ascertain the effects of thevariations.

We are currently in the processof verifying our contact models. Usingour simulation, we will produce asimulation system that automaticallygenerates and solves the equations ofmotion for systems of bodies undergo-ing transitions in multiple contacts. Wewill then thoroughly test our system,considering the whole spectrum ofcontact transitions.

Publications

Refereed

LaFarge, R. A., and C. L. Lewis. 1998.“Contact Force Modeling Between Non-Convex Objects Using a NonlinearDamping Model.” Proc. 1998 Internat.ADAMS Users Conf. 1 (Ann Arbor, MI,8–10 June): 19–25.

LaFarge, R. A., and C. L. Lewis. 1998.“Contact Modeling for RoboticsApplications.” Proc. IASTED Internat.Conf. on Control and Applic. 1 (Hono-lulu, HI, 12–14 August): 254–299.

Tenaglia, C. A., D. E. Orin, R. A.LaFarge, and C. L. Lewis. 1998. “TowardDevelopment of a Generalized ContactAlgorithm for Polyhedral Objects.”Proc. 1999 IEEE Internat. Conf. onRobotics and Automation (Detroit, MI,May 1999), accepted.


3504.270

Parallel CombinatorialOptimization for SchedulingProblems

C. A. Phillips, R. D. Carr, D. A. Jones, E.A. Kjeldgaard, W. E. Hart

Sandia will develop a state-of-the-art massively parallel (MP) combinato-rial optimization engine. This will be thefirst fully general mixed-integer program-ming (MIP) code scalable to thousandsof processors. We will develop twogeneral search strategies for MIP:branch-and-bound and branch-and-cut.We will study the feasibility of an MPversion of a third strategy: branch-and-price. The engine will be able toadaptively incorporate application-specific methods (combinatorialapproximation algorithms and geneticalgorithms), for both lower and upperbounds, to limit the search spaceexplored by the MIP engine. We will usethis exact method in a statisticallyrigorous performance analysis ofsequential heuristics.

We will use the MIP engine tosolve scheduling of stockpile evaluationactivities, neutron-generator manufactur-ing at Sandia, and related schedulingproblems for the Product RealizationProgram, Stockpile Life ExtensionProgram, Revolution in Engineering(formerly ADaPT), and the computa-tional plant. However, MIP is a coreoptimization technology, and thiscapability can be applied in other areasconsistent with Sandia’s mission:nonproliferation, transportation,infrastructure analysis and design,manufacturing, energy, environment,and tools for MP computation such asmeshing and scheduling heterogeneoussupercomputers.

Management of multiple, looselycoupled threads, each distributed andlargely asynchronous, may require thedevelopment of new systems-level tools.Implementation of the search enginealone will require solution of novelglobal and semi-global distributedresource-management problems.

We implemented parallel branch-and-bound for both master-slave andmore general distributed job manage-ment. Code for parallel MIP is in placeand working under message passinginterface (MPI) for multiple processes.We have run the code on a network ofworkstations for up to seven ma-chines. The code can now use any ofthree linear-programming solvers forthe general lower-bounding procedure:CPLEX, XPRESS (DASH associates), andSoPlex. The latter is public domain.CPLEX has agreed to give us researchlicenses for the Accelerated StrategicComputing Initiative (ASCI) machineand will install the code as soon asaccounts are established.

We implemented a new branch-ing method. We used pseudo-cost(gradient) information, which indictseffects on bounds from previousbranches on each integer variable.Since early branching choices canhave a profound effect on perfor-mance, the code now initializes thesegradients via an artificial branch thefirst time it encounters each variable.Hooks are in place for hybridization.We implemented load-balancing. Wehave preprocessing code but have notyet integrated it into the full system.These features represent the state-of-the-art in MIP.

We modeled a scheduling/production-planning problem fromPantex. We formulated the problem asan MIP, taking care to ensure that ouroutput will be comparable with theoutput of the current on-site code (thePantex Processing Model, or PPM). Wemodified the PPM to provide data. Wedeveloped an interface between thisraw data and the MIP engine. Weacquired the data for a challenging testproblem and have partially run thisproblem in serial to verify that theproblem will fit on a single processor.We believe we will be able to solve thisproblem in the near future usingmassive parallelism, improved lower-bounding techniques, better memorymanagement, and more carefulbranching.

Publications

Other

Carr, R. D., J. Eckstein, W. E. Hart, V. J.Leung, and C. A. Phillips. 1997. “Mas-sively Parallel Integer and Combinato-rial Optimization with NationalSecurity Applications.” Presentation toLos Alamos National Laboratory(Invited), Los Alamos, NM, 8 Decem-ber.

3504.280

Programming Paradigms forMassively Parallel Computers

W. E. Hart, M. P. Sears, R. E. Riesen, S. J.Plimpton, R. B. Brightwell

The goal of this project is toenable applications to take full advan-tage of the hardware available onSandia’s current and future super-computers. Currently, nearly all Sandiacodes on existing massively parallelprocessing (MPP) systems use only asingle thread of execution. On thecommodity–based machines, thisapproach will not allow us to achievemaximal performance. More generally,the future of high-end computingappears to be clusters of shared-memoryprocessing (SMPs); i.e., a mixture ofdistributed and shared-memory hierar-chies is exposed to the user. Learninghow to program such machines effec-tively to achieve maximum impact, bothinside and outside Sandia, with simula-tions is a must. The best model for eachof the different types of applications willbe discovered through implementationand exploration of several programmingmodels from both the system andapplication perspectives.

Sandia purchased large SMPboxes from DEC and SGI and gainedaccess to SMP IBM boxes. We workedto understand the nature and pecu-liarities of both the architecture andthe programming models of the SMPboxes from DEC, SGI, and IBM. Further,we surveyed parallelization method-ologies that are appropriate for SMP


clusters and developed conclusionsconcerning where our research effortswould be productively spent. Based onthis survey, we evaluated four pro-gramming models and noted the needfor a general programming environ-ment within which users can tailortheir application to a particularmachine’s hardware. We also evaluatedthread implementations in Linux andidentified a new scheduling methodthat seems appropriate for scientificcomputing applications. We areworking on a thread-aware implemen-tation of message passing interface(MPI) that can take advantage of theextended capabilities that threadsprovide. Finally, we began to explorehow we can leverage the applicationprogramming interface and constructsof MPI to provide the functionalityneeded by a hybrid cluster environ-ment. We expanded the expertise bycollaborating with SGI/Cray and theUniversity of Maryland to providehybrid SMP libraries, models, andapplications codes.

3504.290

Multilevel Techniques forUnstructured Grid Problemson Massively ParallelComputers

C. H. Tong, A. B. Williams, P. R. Schunk,A. C. Robinson, C. D. Moen, J. N. Shadid,R. S. Tuminaro

Robust and efficient linear systemsolution techniques are critical toSandia’s leading-edge scientific simula-tion capabilities. Current paralleliterative techniques suffer deterioratingperformance and even failure as meshsizes increase and geometric complexitygrows (a significant problem forALEGRA, GOMA, FUEGO, and MPSalsa).These difficulties are even morepronounced on larger, massivelyparallel (MP) systems such as Sandia’sComputational Plant (Cplant). Withoutsignificant advances, convergence

limitations will hinder next-generationsimulations.

This project proposes a fundamen-tal change in linear system solutionstrategy at Sandia by providing tools thatfacilitate the use of multilevel (ML)techniques. ML methods offer the bestpromise for overcoming convergencedifficulties with iterative solvers.Unfortunately, ML methods are rarelyused at Sandia due in part to MPimplementation difficulties for unstruc-tured grids. In this project, we will focuson two distinct tasks to address thesedifficulties and facilitate the use of MLpreconditioners. The first corresponds tothe development and analysis ofautomatic coarsening techniques (e.g.,agglomeration) to construct meshhierarchies. The second task is to definemultigrid operators and MLpreconditioners that utilize a givensequence of grids. In this second case wewill specifically consider mesh hierar-chies coming from adaptive meshes(important for MPSALSA and ALEGRA),as well as those arising from automaticcoarse grid generation techniques(important for MPSalsa, FUEGO, andGOMA). We will develop these tech-niques and integrate them in Sandia’sparallel iterative solver library AZTECand incorporate them into Sandia’sapplications, including, but not limitedto, ALEGRA, GOMA, FUEGO, andMPSalsa.

We emphasized four aspects: (1)designed a finite-element (FE) to MLinterface, (2) implemented the Newton-Krylov-Schwarz (NKS) algorithm fornested grids, (3) implemented NKS forindependently generated coarse grids,and (4) studied automatic coarseningalgorithms.

We designed an application-FEinterface to support ML computationsand fully implemented this extensionto the SIERRA finite-element interface(FEI). We also designed and imple-mented a first-version FE-to-MLinterface.

Implementation of the FE-to-MLinterface expends over ten thousand

lines of C code using object-orientedtechniques. Current implementationworks not only for nested grids, butalso for user-provided non-nestedcoarse grids. We also completed andtested integration with AZTEC. We willincorporate the new features in AZTECto support ML in the AZTEC 2.0release.

We completed integration withMPSalsa and tested it using the NKSalgorithm. The new preconditioner notonly gives two to three times improve-ment in solution times on our Paragonand Tflop machines, but it also is morerobust than the local incomplete LUpreconditioner on our test problems(2-D thermal convection problem onstructured and unstructured grids).

We also began to study efficientcoarsening algorithms in the eventthat neither nested nor non-nestedcoarse grids are available. We per-formed a literature search and selecteda few candidate algorithms for furtherinvestigation. In addition, we collabo-rated with UCLA Mathematics Depart-ment on agglomerated ML methods.

Publications

Other

Tong, C. H., R. S. Tuminaro, K. D.Devine, and J. N. Shadid. 1998. “AFramework for Parallel MultilevelPreconditioners on UnstructuredGrids.” Paper presented to the ASCITri-Lab Linear System Meeting,Livermore, CA, 13 October.

Tong, C. H., R. S. Tuminaro, K. D.Devine, and J. N. Shadid. 1998. “Designof a Multilevel Preconditioning Modulefor Unstructured Calculations: Two-Level Schwarz.” Sandia InternalReport, in preparation.

Tong, C. H., R. S. Tuminaro, K. D.Devine, and J. N. Shadid. 1998. “Soft-ware Design and Implementation ofMultilevel Techniques for Unstruc-tured Finite Element Calculations.”Paper presented to the SIAM AnnualMeeting, Toronto, Ontario, Canada, 13July.


3504.310

Scalable Tools for MassivelyParallel DistributedComputing

R. C. Armstrong, L. A. Fisk, A. C. Gentile

Platforms for parallel computingthat harness thousands of independentcommodity machines, such as Sandia’sComputational Plant (Cplant), willrequire robust, efficient, scalable,secure, and easy-to-use tools for systemand user management. Both hard-codedtools, traditionally used on specializedmassively parallel processor (MPP)machines, and high-level tools, exploit-ing features of commodity operatingsystems, will be effective for thesesystems. Both types are designed tomanage MP distributed systems: ananalogy would be the differencebetween PERL and C for creatingcommon UNIX tools—both have theirplace. Generally, trade-offs in thesetypes of tools involve development time,efficiency, and ease of use. Hard-codedtools can be specifically designed forefficiency, but innately take longer todevelop than less efficient, but easier-to-produce, high-level tools. Hard-codedand high-level tools need not existindependently, however. High-level toolscan be prototypes for hard-wired tools,decreasing overall development time.

Utilizing the resources in thedevelopment of Cplant, Sandia willidentify tools whose creation wouldenhance the ability to use and maintainlarge platforms (e.g., controlling userprocesses, monitoring system status).We will develop tools whose perfor-mance is critical in a hard-codedfashion. Tools whose performance is notan issue, or tools expected to be usedinfrequently, will be developed via ahigh-level framework. High-level toolswill also serve as prototypes for hard-coded tools.

(1) We identified and developedsix tools and utilities (both high-leveland hard-coded) for the use, mainte-

nance, and monitoring of largedistributed clusters.

(2) We developed a ServerLibrary for the hard-coded tools thatprovides common services andexports a well-defined applicationprogramming interface (API). Thislibrary allows the hard-coded tools tointeract and speeds overall develop-ment of the tools.

(3) We are in the process ofdesigning and implementing thesecurity infrastructure for the Lilithframework. This infrastructure willprovide flexible, scalable security forthe Lilith–based tools. This work isahead of schedule.

(4) We have tentatively identifieda tool to take through the entiredevelopment cycle of high-level toolsserving as a prototype for a hard-coded tool. Under consideration is aflexible, scalable status monitor forhighly parallel distributed systems.This tool will capitalize on some of theinfrastructure of one of the high-leveltools developed during this first year.

Publications

Refereed

Evensky, D. A., A. C. Gentile, and P.Wyckoff. 1998. “A Visualization Tool forParallel and Distributed ComputingDeveloped via the Lilith Framework.”Paper presented to the 2nd SIGMETRICSSymposium on Parallel and DistributedTools, Welches, OR, August.

Gentile, A. C., D. A. Evensky, and R. C.Armstrong. 1998. “Lilith: A SoftwareFramework for the Rapid Developmentof Scalable Tools for DistributedComputing.” Proc. 7th IEEE Internat.Symp. on High-Perf. Distributed Comput-ing 1 (Chicago, IL, 28–31 July): 360.

Other

Evensky, D. A., A. C. Gentile, and R. C.Armstrong. 1997. “Lilith: SoftwareInfrastructure for Scalable Tools.”Paper presented to SC ’97: High-Performance Networking and Comput-ing, San Jose, CA, November.

3504.320

Massively Parallel Methodsfor Simulating the PhaseField Model

R. M. Fye, S. J. Plimpton, D. Fan, V.Tikare

Prediction of the evolution ofmicrostructures in weapons systems iscritical for meeting the objectives ofstockpile stewardship. For example,accurate simulation of microstructuralevolution in solder joints, cermets, leadzirconate titanate (PZT) power genera-tors, etc., is necessary for predicting theperformance, aging, and reliability bothof individual components and of entireweapons systems. A recently developedbut promising approach called thephase field model (PFM) has thepotential of allowing the accuratequantitative prediction of microstruc-tural evolution, with all the spatial andthermodynamic complexity of a realmicrostructure. Simulating the PFMrequires solving a set of couplednonlinear differential equations, one foreach material variable (e.g., grainorientation, phase, composition,stresses, anisotropy, etc.). While the PFMis versatile and is able to incorporatethe necessary complexity for modelingreal material systems, it is verycomputationally intensive, and it hasbeen a difficult and major challenge toformulate an efficient algorithmicimplementation of the approach. Sandiawill develop and implement numericallyefficient techniques for performing large-scale massively parallel (MP) simula-tions of the PFM. This involves explor-ing, e.g., different discretizations orother alternative implementationapproaches, with issues of accuracy,numerical stability, locality, dissipativity,and parallel efficiency; possiblereductions in the number of requireddifferential equations; generalizations tocertain coupled or more complicatedphysical processes; comparison withexperiment, etc.


In microstructural simulation,using the phase field approach, adifferent field is associated with eachpossible feature. In grain-growthsimulations, one wishes the number Qof possible grain orientations andhence of fields to be as large aspossible, since Q is actually physicallyinfinite. Since the computational timeof grain-growth simulations scaleslinearly with Q, and since grain growthis an important general component ofmicrostructural evolution, this canlead to a bottleneck in microstructuralsimulations. We developed a muchfaster algorithmic approach thatreplaces the multiple (Q) grain-growthphase fields by a single field.

We also investigated a variety ofimplementation issues. For example,we developed a speed-up techniquethat selectively ignores the (dynami-cally changing) less active graininteriors. In addition we investigatedvarious discretization approaches. Thestandard alternating direction implicit(ADI) approach involves tridiagonalsolves across the entire length of thesimulated region. We first found acompletely local and hence moreefficient alternative to ADI thatnonetheless retains ADI accuracy;however, this alternative did not haveas good stability and dissipativityproperties as ADI. We did, however,find a way to increase the time-stepsize while still maintaining stabilityand dissipativity. We are in the processof implementing these and otheralgorithmic speed-ups in a phase fieldgrain-growth code, and have installedcapabilities for varying kinetics andvariable diffusion.

In addition to making the PFMimplementation more efficient, we alsobegan validating the ability of the PFMto simulate microstructural evolutionby comparing to other models and toexperimental data. For example, wecompared the results of two well-understood coarsening processes

using the Potts model and the PFM,confirming that the two approachesgave quantitatively similar results. Wealso simulated a more complexmicrostructural evolution problem ofsimultaneous grain growth anddiffusion. Among other results, thislatter work underscored the challengein determining physically appropriate,free-energy functionals that do nothave undesired numerical artifacts.

3504.330

Visual Explanation andInsight

B. N. Wylie, K. W. Boyack, D. K.Johnson, B. A. Hendrickson, M. H. Koller

With the current trend of informa-tion collection and storage, the quantityof information far exceeds the analyst’sability to comprehend it. Conventionaltools exist for exploring small amountsof data, such as key-word search or text-matching techniques, but these ap-proaches break down when trying todecipher emerging trends and relation-ships within large data sets. Sandia’sknowledge-mining and -managementtool, VxInsight, explores new methodsfor visually presenting the structuralcontext of large sets of relational data.Preliminary use of the tool demonstrateda powerful capability of enablinganalysts to discover information throughtheir interaction within the visualenvironment. Through exploration, userscan detect emerging trends over time,observe interactions of scientific fields,and grasp the overall structure of largedata sets. With the use of encapsulateddata techniques, VxInsight has a broadrange of applications. Currently withinSandia, VxInsight is being used toexplore transaction data for intelligenceagencies, track competitive researchusing patent data, and follow researchtrends in published articles.

Currently, we have not fullyexplored the potential of this tool, andverification of the structures, clustering,and techniques used by VxInsight needto be addressed. We need furtherresearch to begin to understand how thisand other tools will become the basis fora 21st-century knowledge–based society.

• We developed some rudimen-tary verification and validationtechniques for use with the ordinationalgorithm used in the VxOrd tool.Ordination is defined as the process ofgiving 2-D coordinates to a group ofobjects with a user-defined similaritymetric between objects. These initialvalidation techniques include bothquantitative measurements of Euclid-ean distances between similar objectsand repeatability tests with differentrandom seeds.

• We conducted research onother knowledge-management tools,including SGI’s Mineset (3-D visualrelationship tool) and Pacific North-west National Laboratory’s Spire (text–based clustering on documents).

• We explored alternate ordina-tion approaches and developed aninteractive application that allows theuser to define the similarity metric andcontrol the forces guiding the ordina-tion.

• We applied VxInsight to newfields, including transactions andpatent analysis, and are working onfraud, waste, and abuse (FWA).

• We applied VxInsight to real-world problems, including strategicalliance research and weapon partstransaction analysis.

Publications

Refereed

Davidson, G. S., B. Hendrickson, D. K.Johnson, C. E. Meyers, and B. N. Wylie.1998. “Knowledge Mining withVxInsight: Discovery ThroughInteraction.” J. Intel. Inform. Sys. 11(November/December).










ELECTRONICS &

PHOTONICS

Electronics and Photonics solicits research thatensures the supply of Sandia components supportingthe DOE mission of stockpile stewardship. This areaemphasizes concepts that will enable the realizationof small, low-power, highly integrated electronicspackages. Electronics and Photonics projects are repre-sented by two categories of effort: (1) silicon–basedmicrodevices for defense, energy, and industrialuses, seeking new concepts for microelectronics,photonics, microelectromechanical systems (MEMS),and sensors; and (2) integration solutions suitablefor high-yield, high-reliability microsystems, includingintegrated packages capable of communication, self-authentication, and encryption. Because of the potential devastation of losinghuge amounts of information during a power outageor when a computer freezes up, the development ofa method to preserve this information could havea revolutionary impact on society, whether in acommercial, scientific, or home environment. Sucha development would be especially helpful in defensesystems that work in harsh environments, such asthose associated with satellites and nuclear weapons,where a radiation-hardened, low-voltage chip wouldbe invaluable. Information is lost because electrons, which arenot stable, do much of the memory work in electronicdevices. Attempts to create circuits that save theinformation on a computer screen use high voltages,which quickly wear down computer electroniccomponents, and they are expensive. In a project titled “A Novel Nondestruc-tive Silicon-on-Insulator Nonvolatile Memory,” Sandiaresearchers sought to design, fabricate, characterize,and optimize simple circuits to create a novel, low-power, nonvolatile memory. They were successfulin developing techniques that could lead to aninexpensive, low-powered, memory-retaining devicethat may keep computer data from being lost duringa power outage. The technique is simple and requiresonly a few extra processing steps over thosecurrently used in creating microchips. This R&D 100award-winning memory-retentive computer chipuses hydrogen ions as the primary carriers ofinformation. Sandia and its partner in this project have appli-ed for a patent on a prototype memory-retentiondevice that is inexpensive, low-powered, and simpleto fabricate.





3506.190

Advanced Concepts for High-Power VCSELs and VCSELArrays

K. D. Choquette, G. R. Hadley, A. A.Allerman, W. W. Chow

Sandia designed, fabricated, andcharacterized high-power, single- andmultimode, vertical-cavity surface-emitting lasers (VCSELs). We fabricatedVCSELs emitting into a single-transversemode using two approaches: (1)designed novel buried-oxide apertures tooverlap the longitudinal field null, and(2) designed leaky-mode VCSELs usinglateral modification of the cavityresonance to provide the lateralrefractive index difference. Using thefirst approach, we demonstrated single-mode operation to 3.5 mW for 850 nmVCSELs. The second approach resultedin single-mode VCSEL operation to 13times threshold producing 1 mW. Furtherefforts continue for the secondapproach. For high-power continuous-wave (CW) operation, we leveraged 2-DVCSEL arrays. We showed output powersas high as 0.6 W, which were limited bythermal management issues. Weachieved pulsed output power as greatas 1 W using large-area selectivelyoxidized VCSELs. We achieved theoverall project objective to develop high-power, single-mode and multimodesources appropriate for many applica-tions leveraging the many inherentadvantages of VCSELs.

We demonstrated high-powersingle- and multimode VCSELs andaccomplished the following:

(1) Fabricated and packaged 8x8selectively oxidized VCSEL arrays forhigh-power operation. Using anadvanced ceramic pin grid-arraypackage, we demonstrated greaterthan 0.6 W of CW output. The maxi-mum output power is limited by thepackage heat sinking.

(2) Characterized the effects ofthermal crosstalk in 2-D VCSEL arrays.

(3) Found that individual large-area VCSELs producing greater than 15mW maximum output exhibitedunchanged laser characteristics atroom temperature for greater than 300hours.

(4) Demonstrated leaky-modeVCSELs employing transverse cavitymodifications to produce antiguidedoptical confinement for the first time.The leaky-mode VCSELs showed single-mode operation to 13 times thresholdand fivefold improvement overconventional VCSELs. Single-modeoutput power was limited to 1 mW dueto the output mirror coupling. Furtherstudies continue for this technology.

(5) Characterized single-modeVCSELs using thin and thick buried-oxide layers. Although the thin-oxidedevices exhibited lower optical lossand greater mode size, the thick-oxideVCSELs exhibited higher single-modeoutput due to greater modal discrimi-nation.

Publications

Refereed

Choquette, K. D. 1998. “OpticalConfinement in Selectively OxidizedVertical-Cavity Lasers.” Paper pre-sented to the Semiconductor Scienceand Technology Conference, La Jolla,CA, September.

Choquette, K. D., and H. Q. Hou. 1997.“Vertical-Cavity Surface-EmittingLasers: Moving from Research toManufacturing.” Proc. IEEE (Invited) 85(October): 1730–1741.

Choquette, K. D., A. A. Allerman, H. Q.Hou, G. R. Hadley, K. M. Geib, and B. E.Hammons. 1998. “Improved Efficiencyof Small-Area Selectively OxidizedVCSELs.” Proc. 16th Internat. Semicon-ductor Laser Conf. (Nara, Japan,October): 237–238.

Choquette, K. D., A. A. Allerman, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Applications and Performanceof VCSELs.” Paper presented to the

1998 GaAs IC Symposium (plenary),Atlanta, GA, November.

Choquette, K. D., A. A. Allerman, K. M.Geib, B. E. Hammons, D. Mathes, andR. Hull. 1998. “Design of Oxide Aper-ture Profile Within Selectively OxidizedVCSELs.” Paper presented to the 1998LEOS Annual Meeting, Orlando, FL,December.

Choquette, K. D., G. R. Hadley, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Leaky-Mode Vertical-CavityLasers Using Cavity ResonanceModifications.” Electron. Lett. 34(June): 991–992.

Choquette, K. D., G. R. Hadley, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Leaky-Mode Vertical-CavityLasers Using Cavity ResonanceModifications.” Proc. Conf. Lasers andElectro-Optics (CLEO ’98) (San Fran-cisco, CA, May): 587.

Choquette, K. D., H. Q. Hou, G. R.Hadley, K. M. Geib, and B. E. Hammons.1997. “Thick-Oxide Aperture Single-Mode Vertical-Cavity Lasers.” Proc.1997 OSA Ann. Mtg. (Long Beach, CA,October): 245.

Choquette, K. D., H. Q. Hou, K. M. Geib,M. H. Crawford, and B. E. Hammons.1997. “High-Performance SelectivelyOxidized Vertical-Cavity Laser Arrays.”Proc. 44th Nat. Symp.—Amer. Vac. Soc.(Invited) (San Jose, CA, October): 456.

Hegarty, S. P., G. Huyet, J. G.McInerney, K. D. Choquette, K. M. Geib,and H. Q. Hou. 1998. “Size Dependenceof Transverse Mode Structure inOxide-Confined Vertical-Cavity LasersDiodes.” Appl. Phys. Lett. 73 (July):596–598.

Other

Choquette, K. D., W. W. Chow, G. R.Hadley, H. Q. Hou, K. M. Geib, and B. E.Hammons. 1997. “Engineering theOptical Properties of SelectivelyOxidized Vertical-Cavity Lasers.” OSATrends in Optics and Photonics 15(June): 125–129.


3506.110

Wafer Fusion for Integrationof Semiconductor Materialsand Devices

K. D. Choquette, S. H. Kravitz, A. A.Allerman, M. H. Crawford, D. M.Follstaedt

Sandia developed a low-tempera-ture wafer-fusion process to achieveintegration of semiconductor materialsand heterostructures with widelydisparate lattice parameters, electronicproperties, and/or optical properties fornovel devices not possible on any onesubstrate. As a baseline fabricationtechnology applicable to many semicon-ductor systems, wafer fusion hasenabled novel device configurations notpossible by epitaxial growth. Using oursimple process, we developed appropri-ate wafer-fusion techniques for GaAs onAlGaAs, GaAs on GaP, and InP on Si. Wedemonstrated the viability of thistechnology by integrating infrared (IR)vertical-cavity surface-emitting lasers(VCSELs) on transparent AlGaAs andGaP substrates. Thus, we have achievedsubstrate-emitting, short-wavelength,high-performance laser sources for thefirst time.

We optimized the fusion processfor device technology integration ontodissimilar substrates. We fabricatedand characterized bottom-emittingshort-wavelength VCSELs. Specificaccomplishments include the follow-ing:

(1) Examined the fused interfacebetween VCSELs bonded on AlGaAsand GaP transparent substrates bytransmission electron microscopy(TEM). We observed a disorderedinterface region without evidence of

extended defects and did not detectoxygen at the bonded interface.

(2) We achieved reliability testsof IR VCSELs bonded to transparentAlGaAs. The preliminary resultsindicate that the VCSELs exhibit nodegradation over 300 hours ofcontinuous-wave operation at roomtemperature.

(3) We optimized the fusionprocess for bonding VCSELs to GaPand improved the fabrication se-quence for bottom-emitting VCSELs,resulting in high-performance, bottom-emitting, 850 nm VCSELs. For IRVCSELs bonded to GaP, we achieved athreshold voltage reduction of 3 voltsby bonding at 600°C and using appro-priate ohmic contacts.

Publications

Refereed

Choquette, K. D., B. E. Roberds, K. M.Geib, H. Q. Hou, R. D. Twesten, K. L.Lear, and B. E. Hammons. 1997.“Bottom-Emitting 850 nm SelectivelyOxidized VCSELs Fabricated UsingWafer Bonding.” Proc. 1997 LEOS Ann.Mtg. (San Francisco, CA, November):687–688.

Choquette, K. D., H. Q. Hou, M. E.Warren, M. H. Crawford, K. M. Geib,and B. E. Hammons. 1998. “Perfor-mance and Applications of SelectivelyOxidized Vertical-Cavity Lasers.” Proc.1998 IEEE Aerospace Conf. (Snowmass,CO, March).

Choquette, K. D., K. M. Geib, B. E.Roberds, H. Q. Hou, and B. E.Hammons. 1998. “Short-WavelengthBottom-Emitting Vertical-Cavity LasersFabricated Using Wafer Bonding.”Electron. Lett. 34 (June): 1404.

3506.120

Highly Parallel, Low-Power,Photonic Interconnects forInter-Board SignalDistribution

P. J. Robertson, L. E. Shea, V. M. Hietala,K. D. Choquette, L. G. Pierson, M. E.Warren, C. J. Helms

The transmission of digital signalshas become ubiquitous in Sandiaapplications, which range from weaponsinterconnections to secure parallelcomputing and signal processing. Manyof these digital interconnects occur atthe board or connector level and requirelow-power communication of data informats that allow for (1) electromag-netic interference (EMI) immunity, (2)scalability to large numbers of parallelchannels, and (3) large data throughputsover serial links at moderate (< 3 m)distances. In almost all of these cases,separability of links is required to allowfor separately yielded boards that arefield-interchangeable. The separabilityrequirement, in particular, causesproblems for traditional electrical edge-card and cable connectors. In caseswhere a large EMI is present, theseconnectors must provide filtering, whichgreatly limits their potential data rates. Ifscalability is needed, the board-levelelectrical connectors are limited in data-throughput density. This is because suchconnectors are limited by crosstalk andelectrical impedance matching, andmust have a certain area of the metal-to-metal contact to function reliablythrough repeated mating and de-matingsteps. Another factor that limits data-throughput density is the need for equalnumbers of signal and ground lines toprevent crosstalk and ground-bounceeffects. These difficulties can bealleviated with photonic interconnec-tions that provide noncontactingseparable connections, if the photonicinterconnections can be realized at asufficiently low-power consumption.Here, Sandia’s high-efficiency vertical-


cavity surface-emitting laser (VCSEL)technology can be brought to bear, as itcan be combined with appropriateoptics or optical fibers and optimizedphotoreceivers to produce high-density,scalable interconnections that areseparable, but consume much lesspower than previous optical links usinglight-emitting diodes (LEDs) or edge-emitting laser sources. Possible imple-mentations include low-power links thatprovide ultra-high isolation of signalsand limited power transmission andparallel free-space board-to-boardinterconnections for protocol processingapplications.

We focused on enabling tech-nologies and demonstration ofoperating links. We developed ademonstration of the high isolationpower and data transmission connec-tor. In this design, high-power, fiber-coupled lasers illuminate multiplecenter-tapped photovoltaic (PV) cellsfor power transfer to remote modules.Detectors, VCSELs, and optical fibersare held in alignment by submountswithin the connector body, and lightpasses between the two sides of theconnector through windows thatcontain collimating optics. Wedesigned and fabricated applicabledrive and receiver circuitry. Wedesigned and fabricated a 64-elementintegrated receiver array and showedthat individual elements operate at 850nm up to 100 Mbps. We fabricated aflex-circuit optical board holding boththe VCSEL array and the receiverarray. We developed a unique methodof automatically aligning the two free-space optical interconnect boards.This method involved the use of aninfrared digital assistant (IrDA) link(common on laptop computers) as thereverse channel that can operatewithout exact alignment. We accom-plished the mechanical movement ofthe boards using unique Rainbowpiezoelectric actuators. We built andwill use these actuators to align twooptical boards.

Publications

Other

Robertson, P. J., L. Shea, C. Sullivan, K.D. Choquette, L. G. Pierson, K. Gass,and T. Hardin. 1998. “Final Report andDocumentation for the Highly Parallel,Low-Power, Photonic Interconnects forInter-Board Signal Distribution.” SandiaTechnical Report, in preparation.

3506.140

Virtual Reactor for theSemiconductorManufacturing Plant of theFuture

M. E. Coltrin, K. M. Horn, H. K. Moffat, J.F. Klem, K. C. Baucom, C. P. Tigges, T. J.Drummond

This project will develop asophisticated system to enable model–based agile manufacturing in the criticalmetalorganic chemical vapor deposition(MOCVD) and molecular beam epitaxy(MBE) materials growth processesessential to high-speed microelectronicsand optoelectronic components. Thiseffort is founded on a modular andconfigurable process automation systemthat will serve as a backbone allowingintegration of process-specific modelsand sensors. Sandia will develop andintegrate both MOCVD- and MBE-specificmodels in this system and demonstratethe effectiveness of both model–basedand sensor–based real-time feedbackcontrol in improving the accuracy andreproducibility of semiconductorheterostructure growth on MOCVD andMBE systems. In addition, within thisframework we will construct virtualreactor models for both growth pro-cesses and will show how we can usethese models to greatly shorten theepitaxial growth process developmentcycle.

We applied in situ reflectance anda simple real-time feedback controlalgorithm in our MBE growth system.We used this approach to reproduciblygrow a complex indium aluminumgallium arsenide (InAlGaAs) resonant-cavity reflectance modulator structurewith a resonance wavelength positionerror of approximately ± 0.3%.

We demonstrated the generalityand predictive nature of the reflec-tance monitor and feedback algorithmdescribed above by applying them to asubstantially modified modulatorstructure with nearly identical results,without adjusting any model param-eters.

We generalized our analyticalvirtual reactor model of a rotating-diskMOCVD reactor to consider forced-flow situations, i.e., when the reactor isoperated with inlet flow velocities inexcess of the flow required by the idealrotating disk’s natural drawingvelocity. The model can now be usedfor pure stagnation flows, i.e., zerorotation rate or pure rotating diskflows, and for any case between thetwo pure limits. We found a simplescaling relationship to characterize themass transport limited growth rate asa function of two Reynolds numbers,one based on rotation rate and theother based on inlet velocity.

Publications

Refereed

Breiland, W. G., H. Q. Hou, B. E.Hammons, and J. F. Klem. 1998. “In SituReflectance and Virtual InterfaceAnalysis for Compound SemiconductorProcess Control.” Proc. 1998Electrochem. Soc. Nat. Mtg.


3506.160

Selective OxidationTechnology and ItsApplications TowardElectronic andOptoelectronic Devices

O. B. Spahn, A. V. Smith, C. I. H. Ashby,J. P. Sullivan, C. T. Sullivan, J. F. Klem,G. A. Vawter, K. D. Choquette, A. A.Allerman

Selective oxidation of aluminumgallium arsenide (AlGaAs) compoundshas facilitated dramatic improvementsin the performance of near-infrared (IR)vertical-cavity surface-emitting lasers(VCSELs). Sandia will (1) expand ourunderstanding of both the strengths andthe limitations of this technology, (2)explore its applicability to other Al-bearing materials, (3) utilize thistechnology base to demonstrate avariety of new electronic and optoelec-tronic devices, and (4) establish thereliability and manufacturability ofoxidized devices such as VCSELs.Specifically, we will investigate condi-tions required to maximize control ofthe oxidation process as well as thoserequired to facilitate/inhibit etching ofthe resultant oxide. Concurrently, we willperform preliminary studies to extendthe technology to other Al-bearingcompounds such as Al(Ga)AsSb,InAl(Ga)P, and Al(Ga)N. We willconsider several new devices utilizingthe selective oxidation technology ofAlGaAs, as well as of Al(Ga)AsSb. On aseparate front, we will also explore thepossibility of using oxidized AlGaAs andInAl(Ga)P to form GaAs/AlGaAs field-effect transistors (FETs). Finally, we willaddress reliability and manufacturabilityissues of the high-performance VCSELsfabricated using selective oxidationtechnology.

We established a robust, manu-facturable oxidation process thatresulted in the design, fabrication, andtesting of high-power, high-speed,oxide-confined VCSEL structures.Furthermore, extended lifetime testsprove that reliability of the oxidizedVCSELs is comparable to commercialimplanted devices.

We oxidized AlGaAs and evalu-ated it as a waveguide material. Weobtained significantly lower losseswith oxidized layers embedded in thewaveguide than reported by others inthe literature. We observed anomalouspolarization behavior, however, withlaunch polarization appearing to rotateupon propagation of some distance inthe oxidized waveguide.

We modeled how the productionof large amounts of elemental Asduring the oxidation and its diffusioninto adjacent regions can modify theproperties of these regions in waysthat impact device design, fabrication,and performance. The oxidation rate isdetermined primarily by the Al molefraction, but the close proximity of afaster-oxidizing layer can produce aseveral-fold increase in oxidation ratefor a layer of a given Al compositionover the rate obtained with an isolatedlayer of the same composition.Injection of As interstitials intoadjacent layers and the resultingdevelopment of defects, such as Asantisite defects and Group-III vacanciesand interstitials, can alter the oxida-tion rate for nearby regions. Observedrate accelerations are consistent withthe diffusion of As-generated defectsfrom the fast-reaction layer to theslower-reaction layer. Our model,based on the role of elemental As insuch behavior as enhanced oxidationrates in close proximity to faster-oxidizing layers, the effect of relativelayer thicknesses, and dependence ofoxidation rate on position within thetotal structure, provides a semi-quantitative prediction of oxidationprofile for complex structures.

We explored an alternativestrategy for reducing the interfacestate density of insulator-GaAsinterfaces. We applied a sulfur–basedwet-chemical surface passivationtreatment to freshly etched GaAssurfaces prior to formation of theinsulator layer. Early testing involvedthe use of a low-temperature–depos-ited insulator, silicon oxynitride, whichwe chose to reduce the possibility ofsulfur migration from the interfaceduring insulator formation.

Publications

Refereed

Ashby, C. I. H. 1998. “CompoundSemiconductor Surface Passivationand Novel Device Processing.” Paperpresented to the Spring MRS Meeting(Invited), San Francisco, April.

Ashby, C. I. H. 1998. “Device/IC Pro-cessing Challenges for CommercialApplications: Dynamics of Wet Oxida-tion of High-Al-Content III–V Materials.”Paper presented to the 1998 Fall MRSSymposium I: III–V and SiGe Group IV(Invited), Boston, MA, December.

Ashby, C. I. H. 1998. “Material Scienceof Oxidation.” Paper to be presented tothe Gordon Conference ElectronicMaterials: Chemistry, Excitations, andProcessing (Invited), Henniker, NH,July 1999.

Ashby, C. I. H. 1998. “The Critical Roleof Arsenic in Wet Oxidation of AlGaAs.”Paper to be presented to PCSI-26: 26th

Conference on the Physics andChemistry of Semiconductor Interfaces(Invited), San Diego, CA, January 1999.

Ashby, C. I. H., R. D. Twesten, K. D.Choquette, D. M. Follstaedt, K. M. Geib,O. Blum, and H. Q. Hou. 1998. “WetOxidation of AlGaAs: ElementalArsenic and Its Influence on theOxidation Process.” Paper presentedto the 1998 Electronic MaterialsConference, Charlottesville, VA, June.

Ashby, C. I. H., R. D. Twesten, K. D.Choquette, D. M. Follstaedt, K. M. Geib,O. Blum, and H. Q. Hou. 1998. “WetOxidation of AlGaAs: The Influence ofElemental Arsenic on the OxidationProcess.” Paper presented to the 1998Annual Symposium of the New MexicoChapter of the American VacuumSociety, Albuquerque, NM, May.

Choquette, K. D. 1998. “OpticalConfinement in Selectively OxidizedVertical-Cavity Lasers.” Paper pre-sented to the Semiconductor Scienceand Technology Conference, La JollaInstitute, La Jolla, CA, September.

Choquette, K. D. 1998. “The Technol-ogy and Applications of SelectiveOxidation of AlGaAs.” Paper presented


to the 10th Conference on Semiconduct-ing and Insulating Materials (SIMC-X),Berkeley, CA, June.

Choquette, K. D., and H. Q. Hou. 1997.“Vertical-Cavity Surface-EmittingLasers: Moving from Research toManufacturing.” Proc. IEEE. 85 (Novem-ber): 1730.

Choquette, K. D., A. A. Allerman, H. Q.Hou, G. R. Hadley, K. M. Geib, and B. E.Hammons. 1998. “Improved Efficiencyof Small-Area Selectively OxidizedVCSELs.” Paper presented to the 16th

International Semiconductor LaserConference, Nara, Japan, October.

Choquette, K. D., A. A. Allerman, K. M.Geib, B. E. Hammons, D. Mathes, andR. Hull. 1998. “Design of Oxide Aper-ture Profile Within Selectively OxidizedVCSELs.” Paper presented to the 1998LEOS Annual Meeting, Orlando, FL,December.

Choquette, K. D., H. Q. Hou, K. M. Geib,and B. E. Hammons. 1997. “UniformSelectively Oxidized Two-DimensionalVCSEL Arrays for VLSI Photonics.”Paper presented to the 1997 LEOSAnnual Meeting, San Francisco, CA,November.

Choquette, K. D., H. Q. Hou, K. M. Geib,M. H. Crawford, and B. E. Hammons.1998. “High-Performance SelectivelyOxidized Vertical-Cavity Laser Arrays.”Paper presented to the 44th NationalSymposium American Vacuum Society,San Jose, CA, October.

Crawford, M. H., K. D. Choquette, R. J.Hickman, and K. M. Geib. 1997.“Performance of Selectively OxidizedAlGaInP–Based Visible VCSELs.” OSATrends in Optics and Photonics 15: 112.

Hegarty, S. P., G. Huyet, J. G.McInerney, K. D. Choquette, K. M. Geib,and H. Q. Hou. 1998. “Size Dependenceof Transverse Mode Structure inOxide-Confined Vertical-Cavity LasersDiodes.” Appl. Phys. Lett. 73 (August):569.

Li, H., A. Hohl, A. Gavrielides, H. Q.Hou, and K. D. Choquette. 1998. “StablePolarization Self-Modulation inVertical-Cavity Surface-EmittingLasers.” Appl. Phys. Lett. 72 (July):2355.

Other

Choquette, K. D. 1998. “Technology ofSelectively Oxidized Vertical-CavityLasers.” Vertical-Cavity Surface-EmittingLasers—New Technologies and Applica-tions, accepted.

Choquette, K. D., H. Q. Hou, G. R.Hadley, K. M. Geib, and B. E. Hammons.1997. “Thick-Oxide Aperture Single-Mode Vertical-Cavity Lasers.” Paperpresented to the 1997 OSA AnnualMeeting, Long Beach, CA, October.

Choquette, K. D., H. Q. Hou, K. M. Geib,and B. E. Hammons. 1997. “Low-Threshold InGaAs Selectively OxidizedVertical-Cavity Lasers.” Paper pre-sented to the 1997 OSA AnnualMeeting, Long Beach, CA, October.

Choquette, K. D., W. W. Chow, G. R.Hadley, H. Q. Hou, K. M. Geib, and B. E.Hammons. 1997. “Engineering theOptical Properties of SelectivelyOxidized Vertical-Cavity Lasers.” OSATrends in Optics and Photonics 15.

3506.180

Agile Prototyping ofMicroelectromechanicalSystems (MEMS)

H. K. Schriner, C. L. Henderson, K.Current, E. J. Garcia, J. J. Sniegowski, M.S. Rodgers

Under this project Sandia isdeveloping an agile prototyping capabil-ity for microelectromechanical sensors(MEMS) and actuators based onSandia’s state-of-the-art tri-levelpolysilicon micromachining process(Sandia Ultra-planar Multi-level MEMSTechnology [SUMMiT]).

Making Sandia’s state-of-the-artsurface-micromachining technologymore widely available will vastlyincrease its impact. The agileprototyping capability will makeavailable to a variety of both DefensePrograms (DP) and non-DP the ability totest new concepts in this advancedmanufacturing technology in a relativelyshort period of time. Sandia’s capability

to manufacture MEMS structures withthree structural levels of polysilicon andintegrated electronics will be uniqueamong micromachining facilities.

We are ahead of schedule on ourstated milestones, having alreadysuccessfully completed several lots ofwafers in SUMMiT using a reticle thatincludes designs by designers bothinside and outside Sandia. We madethe manufacturing process morerobust and have begun correlatingperformance data with process controldata. We also made good progress ondesign tool development—this year weintegrated design-rule checking intoour computer-aided design (CAD)environment. Finally, we far exceededour goals in developing trainingmaterials for new designers.

We successfully implemented anadvanced design course specificallygeared toward educating designers onthe intricacies in designing in ourcomplex three-layer technology. Wefurther improved our standardcomponents library, design rules, anddesign rule checker, and incorporateda cross-sectional visualization tool andprototyped a 3-D visualizer tool. Wealso successfully fabricated twelvemulti-user reticle sets using designsboth internal and external to Sandia.

Publications

Refereed

Barron, C. C., B. R. Davies, J. J.Sniegowski, M. S. Rodgers, J. H.Comtois, and M. A. Michalicek. 1997.“SAMPLE (Sandia Agile MEMSPrototyping, Layout Tools, andEducation).” Proc. SPIE Micromachiningand Microfabrication Process Technol. III3223 (Austin, TX, 29 September): 10–16.

Schriner, H. K., B. R. Davies, J. J.Sniegowski, M. S. Rodgers, J. J. Allen,and C. Shepard. 1998. “Sandia AgileMEMS Prototyping, Layout Tools,Education and Services Program.”Proc. 2nd Internat. Conf. Engin. Designand Automation CD (EDA ’98, Wailea,HI, 9–12 August).


3506.210

Midwave-Infrared (2–6 µm)Emitter–Based ChemicalSensor Systems

S. R. Kurtz, A. A. Allerman, R. M.Biefeld, A. J. Ricco

Long-wavelength (2–6 µm) diodeemitters are desirable for many applica-tions, including monitoring of chemicalspecies in the environment and manu-facturing, long-wavelength fiber-opticcommunications, lidar, and infrared (IR)detector countermeasures. No practicaldiode lasers are available for any ofthese applications because the bandstructure of bulk III–V, II–VI, and IV–VIsemiconductor alloys results in largeAuger recombination rates at thesewavelengths. Experimental and theoreti-cal work at Sandia resulted in newunderstanding of the electronic proper-ties of narrow-bandgap III–Vheterostructures, and we found methodsto reduce the Auger rates in certainindium arsenide antimony (InAsSb)superlattices and quantum wells (QWs).These devices enable us to beginchemical-sensing demonstrations ofimportant species such as CO–CO2 andnumerous other compounds. Thisproject will involve developing chemi-cal-sensing systems and determining thesensitivity and limitations of thesesystems. Concurrently, we will improveon IR emitters used in these systems.

We demonstrated the firstcascaded lasers and light-emittingdiodes (LEDs) with type I InAsSb QWactive regions using the Sandia-designed reactor. Also, these were thefirst cascaded devices grown bymetalorganic chemical vapor deposi-tion (MOCVD). The broadband LEDsproduced high average powers, > 2mW (@ 80°K, 3.7 µm) and > 0.1 mW (@300°K, 4.3 µm). The 10-stage, 3.8–3.9µm laser operated up to 180°K. At80°K, we observed peak laser power> 100 mW and a slope efficiency of 48%(4.8% per stage). Slope-efficiency wasstrongly dependent on cavity length,and analysis of efficiency data suggestsan internal quantum efficiency > 1 anda loss coefficient * 100 cm-1. We are

optimistic that advances in materialquality and device design will improvecarrier confinement and reduce loss,leading to higher efficiencies andhigher-temperature operation ofcascaded InAsSb lasers.

We examined by optical pumpingseveral laser structures grown in theSandia MOCVD reactor. These struc-tures consisted of an InAs substratewith a 2.5 µm-thick AlAsSb lowercladding, a 1.0 µm-thick InAsSb/InAs(833 / 873) strained-layer superlattice(SLS) active region and severaldifferent top terminations. We pumpedthe SLS laser with a Q-switchedNd:YAG (1.06 µm, 20 Hz, 10 ns pulse,focused to a 200 µm-wide line) anddetected emission with a Fouriertransform infrared (FTIR) operated in astep-scan mode. We observed laseremission from cleaved bars, 1000 µmwide, with uncoated facets. We saw alasing threshold and spectrallynarrowed laser emission from 80°Kthrough 240°K, the maximum tempera-ture where lasing occurred. At 80°K,we could obtain peak powers > 100mW. The temperature dependence ofthe SLS laser threshold is described bya characteristic temperature, T0 = 33°K,over the entire range. Similar experi-ments on structures containing 20003

InAs top and bottom wave-guidingregions resulted in improved power(> 650 mW) at 80°K and 3.8 µm. Weobtained this result using an 808 nmdiode stack pump laser with a 2% dutycycle and 50 µs pulses in collaborationwith Phillips Laboratory.

Publications

Refereed

Allerman, A. A., S. R. Kurtz, R. M.Biefeld, and K. C. Baucom. 1998. “10-Stage, Cascaded InAsSb Quantum-WellLasers at 3.9 µm.” Electron. Lett. 34 (19February): 369–370.

Kurtz, S. R., A. A. Allerman, R. M.Biefeld, and K. C. Baucom. 1998. “HighSlope Efficiency, Cascaded Mid-Infrared Lasers with Type I InAsSbQuantum Wells.” Appl. Phys. Lett. 72(27 April): 2093–2095.

3506.230

A Novel NondestructiveSilicon-on-InsulatorNonvolatile Memory

J. R. Schwank, M. R. Shaneyfelt, D. M.Fleetwood, J. R. Murray, B. L. Draper, W.L. Warren

Radiation-hardened nonvolatilememories are used in several Sandia,other DOE, and DoD systems for bothprogram and critical data storage. Thisproject will design, fabricate, andcharacterize a novel nondestructive,low-power, nonvolatile memory basedon protonic transport in the buriedoxides of silicon-on-insulator (SOI )transistors. SOI technology offersadvantages over bulk-silicon (Si)technology for high-speed/lower-powerand radiation-hardened (single-eventupset [SEU] and high dose rate)applications. We performed previouslaboratory work that shows that themost common techniques used tofabricate SOI substrates cause manyoxygen vacancies in the buried oxide. Ifthese oxides are exposed to hydrogen atmoderate temperatures (600°C to800°C), mobile protons can be gener-ated. These protons can be made tomove from the top to bottom oxide/Siinterface by application of an electricfield. The motion of the protons formsthe basis for a nonvolatile memory. Inthe first two years of this project, weexamined methods for optimizingprotonation effects in capacitors. Wedeveloped a circuit architecture forfabricating an SOI–based nonvolatilememory. One of the key goals of thiswork was to demonstrate that mobileprotons could be generated in a state-of-the-art processing facility. In addition,we performed experiments to betterunderstand the mechanisms for protonincorporation and the effects of ionizing


irradiation on protonic transport andmemory retention. We will investigateprotonic transport in transistors andbuild a simple one-cell nonvolatilememory. We will characterize transistortest structures for their electrical,radiation, fatigue, and retention proper-ties. We will also demonstrate at thetransistor and integrated circuit (IC)level the feasibility of an SOI nonvolatilememory based on proton motion in theburied oxide.

Previously, we expended consid-erable effort at optimizing annealconditions for maximizing voltagehysteresis on capacitors. Previousdevice structures used aluminum (Al)metallization and, consequently, wecould not perform repeated anneal/measurements. Because the turn-around time for fabricating capacitorlots was normally more than twomonths, this severely limited thenumber of anneal variations. Togreatly enhance the number ofvariations of anneal cycles, we devel-oped a process flow that uses TaSiinstead of AlSi for this work. The TaSimetallization contacts can withstandpost-annealing treatments up to 900°C,and repeated anneal/measurementcycles can be performed. We per-formed several different types ofhydrogen anneals, including standardfurnace anneals, rapid thermal anneals(RTA), and vacuum anneals. Weobtained the best results from samplesusing RTA with a fast ramp-up totemperature and a fast ramp-down. Weobtained the maximum hysteresisvoltage shifts around 3 V for a 700°C,15-minute RTA anneal on small piecesof wafers (< 1 in.2). These shifts aresufficient to fabricate a nonvolatilememory. Unfortunately, the uniformityacross the sample was poor (1 to 3 V,typical). We developed two memoryarchitectures for the SOI nonvolatile

field-effect transistor (NVFET). Thefirst is an electrically erasable pro-grammable read-only memory(EEPROM) cell that consists of anNVFET and an n-channel metal-oxidesemiconductor (NMOS) accesstransistor. During a read mode, weground the gate so there is no risk ofupsetting the data in the cell. We donot use the gate to select which cell toread, so we require an access transis-tor. The second option is a Flasharchitecture. The advantage of thisapproach is that we require only oneNVFET per cell and no access transis-tor. The disadvantage is that the gateof the NVFET is biased during readoperations.

Publications

Refereed

Vanheusden, K., D. M. Fleetwood, J. R.Schwank, M. R. Shaneyfelt, T. L.Meisenheimer, and B. L. Draper. 1998.“The Effect of Irradiation and ProtonImplantation on the Density of MobileProtons in SiO2 Films.” IEEE Trans.Nucl. Sci., accepted.

Vanheusden, K., J. R. Schwank, W. L.Warren, D. M. Fleetwood, and R. A. B.Devine. 1977. “Radiation-Induced H+Trapping in Buried SiO2.” J.Microelectron.Engin. 36 (June): 241–244.

Vanheusden, K., R. A. B. Devine, J. R.Schwank, D. M. Fleetwood, R. G.Polcawich, W. L. Warren, S. P. Karna,and R. D. Pugh. 1997. “IrradiationResponse of Mobile Protons in BuriedSiO2.” IEEE Trans. Nucl. Sci. 44 (Decem-ber): 2087–2094.

Vanheusden, K., W. L. Warren, D. M.Fleetwood, J. R. Schwank, M. R.Shaneyfelt, B. L. Draper, P. S. Winokur,R. A. B. Devine, L. B. Archer, G. A.

Brown, and R. M. Wallace. 1998.“Chemical Kinetics of Mobile-ProtonGeneration and Annihilation in SiO2

Thin Films.” Appl. Phys. Lett. 73(August): 674–676.

Vanheusden, K., W. L. Warren, R. A. B.Devine, D. M. Fleetwood, J. R. Schwank,M. R. Shaneyfelt, P. S. Winokur, and Z.J. Lemnios. 1987. “Nonvolatile MemoryDevice Based on Mobile Protons inSiO2 Thin Films.” Nature 386 (April):587–589.

Warren, W. L., D. M. Fleetwood, J. R.Schwank, M. R. Shaneyfelt, B. L.Draper, P. S. Winokur, M. J. Knoll, K.Vanheusden, R. A. B. Devine, L. B.Archer, and R. M. Wallace. 1997.“Nonvolatile Field-Effect TransistorsBased on Protons in Si/SiO2/Si Struc-tures.” IEEE Trans. in Nucl. Sci. 44(December): 1798–1797.

Warren, W. L., K. Vanheusden, D. M.Fleetwood, J. R. Schwank, M. R.Shaneyfelt, P. S. Winokur, and R. A. B.Devine. 1996. “Proposed Model forPositive Charge in SiO2 Thin Films:Over-Coordinated Oxygen Centers.”IEEE Trans. on Nucl. Sci. 43 (Decem-ber): 2617–2626.

Other

Schwank, J. R., M. J. Anc, M. R.Shaneyfelt, B. L. Draper, T. L.Meisenheimer, W. L. Warren, K.Vanheusden, D. M. Fleetwood, and L. P.Schanwald. 1997. “Improving ITOXConditions for Low Defect Density andBOX Breakdown.” Proc. 1997 IEEEInternat. SOI Conf. (Yosemite, CA,October): 14–15.

Vanheusden, K., W. L. Warren, W. M.Shedd, R. D. Pugh, D. M. Fleetwood, J.R. Schwank, and R. A. B. Devine. 1997.“Characterization of Interface Traps inSOI Material.” Proc. 1997 IEEE Internat.SOI Conf. (Yosemite, CA, October): 64–65.


3506.240

Integration ofOptoelectronics and MEMSby Free-Space Microoptics

M. E. Warren, F. M. Hosking, A. A.Allerman, G. A. Vawter, J. R. Wendt, O.B. Spahn, R. E. Asbill, J. H. Smith

Combining microelectromechani-cal systems (MEMS) with optoelectroniccomponents is a means of realizingcompact optomechanical subsystems.Some examples are laser beam scan-ning, switching and routing and activefocusing, and spectral filtering orshuttering of optical sources. A majorobstacle to realizing these types ofsystems is the difficulty of integrating thetwo technologies. The devices usedissimilar materials with significantproblems for a common process line.Another major difficulty with directintegration is providing the optical pathfor the MEMS components to interactwith the light source. Simply stackingone device on top of another is notcompatible with many optical wave-lengths. Sandia will use folded opticalpaths in a transparent substrate toprovide the interconnection routebetween the components of the system.The components will be surface-mounted by flip-chip bonding thesubstrate. Microoptics can be fabricatedinto the substrate to reflect and refocusthe light at precise angles so that it canpropagate from one device to anotherand be directed out of the substrate intofree space. The MEMS components donot require the development of transpar-ent optics and can be completelycompatible with the current three-levelpolysilicon process. The optoelectronicsdevices will be vertical-cavity surface-emitting laser (VCSEL) arrays that are

ideally suited for surface-mounting. Thistechnology will enable the combinationof two very successful activities—siliconMEMS and III–V optoelectronics—toaddress applications in weaponssystems, sensor systems, and otherareas. Optical systems that can beminiaturized include beam scanning forsensing, communications or displays,active focusing for motion sensing ortracking, and 2-D arrays of phaseshifters for real-time reconfiguration ofoptical systems or miniature displays.

This year’s work emphasizedpostprocessing MEMS componentsfabricated at Sandia. Thesepostprocessing techniques includemetallization of MEMS devices eitherbefore or after release, deep viaetches, and complete release process-ing, including self-assembled mono-layer coatings and sublimation drying.Prerelease metallization consists ofgold coatings, which can survive thesubsequent release etch and arepatterned by conventional lithogra-phy; postrelease coatings are appliedby shadow masking. The coatingsallow for high-reflectivity polysiliconmirrors and for metallic bondpads forimproved wire bonding and flip-chipbonding. The deep via etch processallows for transmission of lightthrough the MEMS substrate thatwould otherwise be absorbed. Theprocess allows vias to be etched all theway to the first oxide layer in theMEMS process from the back of thewafer. In addition to optical access, thevias are useful to improve the releaseof large structures and for advancedpackaging and electrical interconnectconcepts. The other area of processdevelopment is flip-chip bondingprocesses that can be used tomechanically and electrically intercon-

nect MEMS and optoelectronicdevices. Continued improvement inthe gold thermocompression flip-chipbonding process includes destructivetesting to investigate ways to improvethe bond strength, and preliminaryinvestigation of possible underfilladhesives that would improve bondstrength while compatible with opticalapplications. We developed solder-bump bonding based on a solder-plating capability. We demonstratedgood reproducibility of the solderplating and fluxless reflow of thesolder and bonded some devices withthis technique. We also developed analternative to electroplating of solder,using an automated dispensing systemfor solder pastes. We developedoptical designs for a scanning systemincorporating moving MEMS mirrorsand VCSEL arrays and will submitthese designs for fabrication soon. Weperformed a number of functionaldemonstrations of optical systemswith MEMS structures.

Publications

Other

Blum, O., M. E. Warren, H. Q. Hou, R. F.Carson, K. D. Choquette, M. S.Rodgers, and J. J. Sniegowski. 1998.“Combined Photonics and MEMSFunction Demonstration.” Proc. SPIEPhotonics West 3286 (San Jose, CA, 25January): 57–61.

Warren, M. E., O. Blum, C. T. Sullivan,R. J. Shul, M. S. Rodgers, and J. J.Sniegowski. 1998. “The Integration ofSurface-Micromachined Devices withOptoelectronics: Technology andApplications.” Paper presented to theTopical Meeting on Optical MEMS,Monterey, CA, 20–22 July.


3506.250

Advanced Laser Structuresfor Short-Pulsed Power inActive Optical SensorSystems

G. A. Vawter, A. A. Allerman, F. J.Zutavern, W. W. Chow, G. R. Hadley, A.Mar

To address the technologicalneeds of Sandia customers in DOE andDoD for high-power, low-cost, reliable,pulsed lasers in the 0.01–100.0 nsregime, we will develop diode lasers forshort-pulse duration and high-peak pulsepower. Our goal is up to 10 W, whilemaintaining good far-field beam qualityand ease of manufacturability for lowcost. We will achieve high-peak-powerpicosecond pulses by gain switchingflared-geometry waveguide lasers andamplifiers. In the longer pulse-lengthregime, we will obtain 1 to 100 ns pulsesusing conventionally pumped ridgewaveguide lasers of unique design. Wewill use novel very large optical cavity(VLOC) lasers to achieve high-saturated-output power.

A second, far-reaching aspect ofpulsed diode lasers is their uniqueability to generate very high repetitionrate optical pulses in the microwave andmillimeter-wave regime. We will exploreexperimentally all-optical monolithicintegrated microsystems for directgeneration of radio-frequency (RF) andmillimeter-wave frequencies. Based onour successful demonstration of 90 GHz

power generation from mode-locked ringdiode lasers, we will explore newtechniques to reduce noise in the outputsignal and actually tune the outputfrequency by adjusting bias currentswithin the laser.

• Flared output lasers. We (1)redesigned the flared lasers forreliability, yield, and power extraction,(2) activated a photoconductivesemiconductor switch (PCSS) using again-switched laser, (3) demonstratedgreater than 14 W peak output powerfrom a flared laser in a 30 ps pulse, (4)fabricated, packaged, and tested flaredlasers appropriate for use as pumpsources for optical frequency conver-sion, (5) designed and built master-oscillator-power-amplifier (MOPA)lasers, which we will test next year forevaluation of output couplers, and (6)completed the gain-switched lasermodel.

• LOC nonflared lasers. We (1)improved the process technology forhigher yield and output power, (2)demonstrated 560 mW peak outputpower from a VLOC laser using 1 µsdrive pulses, (3) observed the pre-dicted large, two-dimensionallyexpanded optical mode, (4) identifiedpower limitations arising from thestrong coupling of material refractiveindex to temperatures whereinsignificant deviation of the internaltemperature from the simulated valuecauses loss of oscillation of the desiredfundamental optical mode, and (5)proposed a new type of VLOC laserusing vertically stacked waveguides

with an antiguide-type coupling regionto obtain the desired large opticalmode without the temperaturesensitivity observed in previousdesigns.

• Mode-locked ring lasers for RFgeneration. We (1) designed a widerange of ring-cavity lasers withintegrated amplifiers and photodetec-tors for investigation of linewidth,noise, and frequency tuning, (2)designed both single-lateral-mode andmultilateral-mode devices for explora-tion of reduced linewidth under single-mode operation, (3) developed robustprocess technologies for oxygenimplantation and dielectric isolation,and (4) began fabricating mode-lockedring lasers.

Publications

Refereed

Vawter, G. A., C. T. Sullivan, J. R. Wendt,R. E. Smith, H. Q. Hou, and J. F. Klem.1997. “Tapered-Rib Adiabatic-FollowingFiber Couplers in Etched GaAs Materi-als for Monolithic Spot-Size Transfor-mation.” IEEE J. Selected Topics inQuantum Electron. (Invited) 3(6)(December): 1361–1371.

Vawter, G. A., C. T. Sullivan, J. R. Wendt,R. E. Smith, H. Q. Hou, and J. F. Klem.1998. “Tapered-Waveguide ModeExpansion in Etched GaAs Materialsfor Low-Loss Coupling of PhotonicStructures to Optical Fiber.” Paperpresented to the 1998 OSA AnnualMeeting/ILS-XIV (Invited), Baltimore,MD, 4–9 October.


3506.260

Metal Micro-Heat-PipeSubstrates for High-Power-Density Electronics

D. A. Benson, S. H. Kravitz, C. V. Robino,S. N. Burchett

Sandia will develop a newefficient substrate for cooling microelec-tronic systems. As electronic systemrequirements move toward higherprocessing speeds and ever-smallerweight and volume requirements,electronic cooling capabilities increasein importance. Sandia found that amajor advance in cooling is nowpossible using an efficient Sandia micro-heat-pipe design combined with a metalsubstrate. A metal substrate such asKovar matches the coefficient of thermalexpansion of semiconductor die whilethe micro-heat-pipe gives very higheffective thermal conductivity. The resultis a robust, potentially low-cost andefficient cooling technology. First wedeveloped processes and made andtested an initial prototype. Next weoptimized prototypes for improvedperformance. We made new wicks withlow-drag radial features, with multilayerpatterns and overplated capped designs.We developed a model of the heat-pipeto allow us to assess the devices for newapplications and to predict the heat-pipebehavior for new substrate geometries.

We developed a finite-element(FE) model of the substrate for thesubstrate and support structure tomeet design needs. The results defineda substrate design with sufficiently lowstress levels in the die attach layer fora prototype application. We developedprocesses for the photo-mask produc-tion of a wick structure on metalsubstrates. We defined laser weldschedules for the assembly and sealingof the substrate. We used a simpledevelopmental fill-and-seal process tocomplete the first prototype. Finally,we developed an infrared (IR) thermaltest system and measured the firstresults for heat-transfer properties of

the prototype design. The initial heat-pipe substrate prototype showed atwofold improvement of effectiveconductivity over a similar geometrywith only Kovar. We completed thecomputational model of stresses in thedie and Kovar wall material. Theresults of the model analysis show nomajor design limits in die attachstresses. We improved weld-and-filltube designs for future applications.We tested new prototypes with radial,multilayer, and capped features of thewicks. Heat-transfer results can now beexpressed with a 3-D numericallysolved heat-pipe model, which allowsus to compare performance withexisting cooling technologies forspecific application designs. Discus-sions on Defense Programs (DP) andindustry–based applications are beingpursued to use this technology in newelectronic designs.

Publications

Refereed

Benson, D. A., et al. 1998. “SubstrateKeeps Today’s Hot Chips Cooler.” OEReports, SPIE Internat. Soc. for OpticalEng. 178 (October): 16.

Benson, D. A., R. T. Mitchell, M. R.Tuck, D. W. Palmer, and G. P. Peterson.1998. “Ultra–High-CapacityMicromachined Heat Spreaders.”Microscale Thermophys. Engin. 2(February): 21–30.

Other

Benson, D. A., C. V. Robino, D. W.Palmer, and S. H. Kravitz. 1997. “HeatPipe with Improved Wick Structures.”U.S. Patent Application based onDisclosure SD-6089 S-89,239 (Washing-ton, DC, 10 December).

Benson, D. A., R. T. Mitchell, M. R.Tuck, D. R. Adkins, D. Shen, and D. W.Palmer. 1997. “Micromachined HeatPipes in Silicon MCM Substrates.”Sandia Technical Report SAND97-0100(January). Sandia National Laborato-ries, Albuquerque, NM.

3506.280

Vacuum Encapsulation ofMEMS Structures

S. Montague, J. G. Fleming, A. J. Farino,J. J. Sniegowski, B. D. Staple

The monolithic integration ofmicroelectromechanical systems(MEMS) with driving, controlling, andsignal-processing electronics on a singlechip have enabled the recent develop-ment of a new class of high-performanceinertial and other sensors. Developmentof on-chip vacuum encapsulation is acritical enabler for many of these newMEMS sensors. The commercial interestin this area is extremely high. A reliable,on-chip vacuum encapsulation technol-ogy is critical. Vacuum encapsulation ofMEMS sensors will lower their cost, size,and operating voltages while increasingtheir sensitivities. In addition, vacuumencapsulation facilitates wafer-scaleMEMS release and electrical testing andgreatly simplifies the packaging process.

We accomplished the followingtasks:

(1) Designed a complete reticleset of various resonant sensors andvacuum-encapsulated test structures.This included analyzing the deflectionof the 4-micron vacuum lids forvarious geometries and sizes, investi-gating the use of different-spacedpolysilicon columns for supportinglarge-vacuum areas, and interconnect-ing the MEMS sensors with thecomplementary metallic oxide semi-conductor (CMOS) electronics.

(2) Developed an extensiveintegrated circuit (IC) fabricationprocess for fabricating the MEMSsensors with on-chip vacuum encapsu-lation and started two wafer lots tomanufacture the integrated devices.

(3) Ran a short-loop lot toanalyze the feasibility of using evapo-rated versus sputtered aluminum (Al)in the final vacuum-sealing process.The results indicate that evaporated Alhas the potential of providing a goodseal. Evaluations of the final sealingprocess are ongoing.


3506.290

Massively Parallel SensorArrays for Volatile OrganicDetection

A. J. Ricco, A. W. Staton, W. G. Yelton, J.W. Bartholomew

Sandia will develop a flexiblechemical sensor microlab (µlab) fordetecting volatile organic compounds(VOCs) with high chemical selectivitybased on large (~ 20 sensors) arrays ofsorption–based resistors and surfaceacoustic-wave (SAW) devices. This µlabwill comprise a massively parallel (MP)microsensor array using inexpensive,easily fabricated, polymer-coated,planar interdigitated resistors/polymersthat are rendered conductive throughadmixture of conductive colloidalparticles. Using chip–based electronics,sensor-array resistance changes due toVOC exposure can be monitoredinexpensively in real time. The responseof each sensor is rapid, reversible, andrepeatable; hundreds of polymers withdistinct sorptive characteristics arecommercially available. Limits ofdetection (LODs) can reach ppb (parts-per-billion) levels; for high-volatilityspecies, this is likely to require adding apreconcentrator as a front-end for thisµlab. In contrast to separations–basedµlab concepts, this approach is analo-gous to spectroscopy: The rich spectrumof resistor responses enables highchemical selectivity through multivariateanalyses without separations; sensorredundancy provides improved systemrobustness.

The detection of VOCs is a keynational security concern—detection ofthe proliferation of weapons of massdestruction (WMD). Particular combina-tions of chemical precursors, solvents,and by-products signal the production ofnuclear, chemical, and biological WMD.

We will determine system performancefor WMD compounds, including variousmulticomponent VOC mixtures and theirrelevant LODs. In addition, DOEenvironmental monitoring andremediation applications, as well asindustrial-waste minimization, requirethe development of effective, inexpen-sive VOC µlabs; we will address keyspecies, as well, many of which arepotential interferants for WMD detectionand must therefore be included in anycase.

Previously we focused on 20polymer/colloid film combinations. Weare using primarily 40%-by-weightloading of the polymer matrix withgraphitized carbon (27–30 nm particlesize). To date, we have run step-injection and isotherm (0.05–20%P/Psat.) analyses using 20 WMDanalytes and interferants, as well as 5binary chemical mixtures. We testedboth dip-deposited coatings (thickerfilms) and high-speed spin-cast films(3000 rpm for 30s, producing ~ 200 nm-thick films). Promising results indicatethe ability to unambiguously detect arange of organics.

We are working to improve thecolloidal distribution of carbon inpolymers that are lyophobic. To date,we have studied five commercialsurfactants (dispersing agents),resulting in five kinetically stablepolymer/sol solutions with particleagglomerates less than 5 mm. Finally,we are studying a promising polymer/carbon composite based on PEVA(polyethylene vinyl acetate) at carbonloadings of 15%, 20%, 25%, 30%, and40% by weight to determine itspercolation threshold, where sensitiv-ity may be greatest.

We made and tested films usingfour ratios (7:1, 8:1, 9:1, and 10:1) ofpoly(ethyleneoxide) (PEO) to lithiumperchlorate (LiClO4). Though concep-tually similar to the electronically

conductive carbon-loaded polymercomposites, these materials differ intheir fundamental mechanism ofdetection: The principal conductivitymechanism is the motion of ions. Teststo date have focused on step-injectionanalyses with 11 analytes and includedimpedance and phase analyses withfrequencies from 100 mHz to 1 MHz.

We microdispensed five films(~ 20 by 400 mm) on fabricated,chemically sensitive field-effecttransistors (chemFETs), which allowresistance and work function measure-ments on a single chemically sensitivelayer. Leveraging SAW sensor arraywork, we are assembling results from alarge library of SAW coatings (ca. 30)to evaluate and refine visually empiri-cal region of influence (VERI) patternrecognition (PR) methods for verylarge coating arrays.

We were able to stabilize 10 morepolymer/sol solutions with commercialsurfactants, for a total of 15 kineticallystabilized films. We studied over 160samples to address the stabilityproblem.

We completed the fourth trainingdata set from a 12-chemiresistor array.Each training set is the combination of18 analytes.

We completed a flow systemhardware to provide low-ppb concen-tration of key analytes and are addinga spectrometer to the output to verifyppb-level concentrations.

We are near completion of thehardware for the first prototype µlabsystem. This hybrid system will have aseven-sensor SAW array with fiveclasses of films. The system will becapable of detecting and identifyingkey analytes from the built-in PRalgorithms and training library. Workcontinues in developing the micro-dispensing of 20+ chemiresistorsolutions onto a platform arraysuitable for the µlab system.


3506.270

Integration of MicrosensorTechnology into a MiniatureRobotic Vehicle

R. H. Byrne, C. Anderson, E. J. Heller

The goal of this work is to developa miniature robotic vehicle capable ofdeploying environmental sensors (likeSandia-invented radiation field-effecttransistors [RadFETs], volatile organiccompounds [VOCs], hydrogen sensors,etc.) and navigation sensors (likeSandia’s three-axis accelerometer). Wewill fabricate the sensor, signal process-ing, communications, power, and controlelectronics using surface-micromachining techniques. We willfabricate the vehicle chassis and drivemechanism using various precision-machining technologies developed atSandia. We will use electromagnetic(EM), optical, or other signals to powerand communicate with the vehicle. Abase station will transmit commandsignals to the vehicle, which will directthe vehicle to reposition itself, takesensor readings, or transmit sensorreadings. We will determine the locationof the vehicle in two ways, first bymeasuring the time of flight (TOF)between multiple base-station transmis-sion and reception signals, and second,via navigation sensors. Combiningvehicle position and environmentalsensor information will make it possiblefor multiple vehicles to map out thelocation and characteristics of radioac-tive, chemical, military, or other entities.While the ultimate goal of this project isto fabricate working prototype units, thisproject will also focus on developing theintegration technologies (includingintegrating control and sensing electron-ics with sensors in single dies) neces-sary to design, build, and test future

intelligent miniature systems for DOEand DoD applications. This process willassess current internal and externalcapabilities, specify the design andanalysis tools, develop a prototypemanufacturing and testing environment,and design and fabricate prototypevehicles and sensors.

We developed a 0.5-cubic-inchprototype robotic vehicle propelled bytwo miniature brushless dc motorsthat drive small wheels. We achievedtwo-way communications with aninfrared (IR) link. We used a hand-heldoperator control unit to send com-mands to the vehicle. The vehicleelectronics consist of an 8051-compatible microprocessor, motorcommutation electronics, and the IRcommunications module. A six-layer0.75-by-0.79-inch printed circuit boardcontains all of the surface-mountvehicle electronics. The printed circuitboard is also the main component ofthe robotic vehicle. The robot ispowered by a battery pack thatconsists of four NiCd or nickel metalhydride batteries in series that provide11 mAh of capacity.

Battery energy density and thepower requirements for mobility andsensing are critical items that must betackled to develop a smaller roboticvehicle. The motors currentlyemployed for mobility draw a signifi-cant amount of current relative to theother electronics on the vehicle. Tomeet the ultimate size goal of 0.25cubic inch, we are exploring moreefficient mobility methods that requireless power and are smaller than thebrushless dc motors currently used.Piezoelectric materials are promisingand are being investigated. In an effortto reduce the size of the robot further,we are also exploring wafer-scaleintegration or having a commercial

application-specific integrated circuit(ASIC) company design a single-chipversion of our current design.

The hand-held operator controlunit uses the same Atmel processor asthe robotic vehicle. The range of the IRremote is proportional to the squareroot of the light-emitting diode (LED)transmit current. We are investigatingincreasing the range further usingSandia-developed vertical-cavitysurface-emitting laser (VCSEL) technol-ogy to replace the discrete LEDs.

Publications

Refereed

Byrne, R. H., and C. Anderson. 1998.“Design of a Miniature Robotic Ve-hicle.” IASTED ’99 Conference, submit-ted.

3506.320

Precision-FormedMicromagnets

T. R. Christenson, E. L. Venturini, T. J.Garino

The feature of permanent mag-nets, and in particular rare-earth (RE)–based permanent magnets, that makestheir use compelling in the microdomainis that their magnetization remainsindependent of scale. This situation is incontrast to electromagnetic (EM) coils,where constraints due to current densitylimits do not allow one to maintain agiven magnetic field with a particularscaled coil. Even superconductors sufferthe same limitation. Many uses ofpermanent magnets on the microscale,however, require that they be fabricatedto small dimensions and correspondingtolerances. Fabricating permanentmagnet materials is not only difficult


and expensive, but in situations wheremicrosize multipole magnets areneeded, it is not practical: Establishingmulti-oriented high magnetic fields in asmall volume is prohibited by coilscaling, which is the means used tomagnetize magnetic material. Theimplementation of microsized perma-nent magnets, however, will yield devicefirsts such as novel static microdevicesand more efficient magnetic micro-motors. The primary technique beingpursued to fabricate micromagnets isderived from bonded RE permanentmagnet fabrication and precisionmolding achieved with the use of deepx-ray lithography-patterned mold forms.Sandia used resulting prismatic moldswith dimensions down to 5 microns,thicknesses up to several millimeters,and tolerances less than 0.5 micron toincorporate permanent magnet powdermixed with a binder material. Asubsequent batch-magnetizing stepresults in an array of permanentmagnets batch-fabricated on a substratewith maximum energy products of 10MGOe (Mega-Gauss-Oersted). We areinvestigating methods to increase theenergy product by using anisotropicpowder as well as incorporating a fullydense sintered RE magnet. A currentmethod proposed to implement higher-density permanent magnets uses anintermediate mold obtained by accu-rately molding ceramics into thePlexiglas deep x-ray lithography mold asused previously.

The bonded NdFeB micromagnetprocess has become nearly routine. Wefabricated bonded micromagnets usingdeep x-ray lithography-defined moldsin a geometry suitable for 5 mm-diameter four- and eight-pole rotors tobe used in an 8 mm-diameter by 1 mm-thick brushless dc motor that we areconstructing. We fabricated many

other shapes of interest, including ringsections that, when assembled,constitute miniature Halbach arrays(magic cylinders) that create magnifieduniform static fields.

We characterized the trade-offbetween maximum energy product ofbonded NdFeB micromagnets versusmechanical strength for variouspercent composition of bindermaterial. At 20% by volume of anepoxy binder, we achieved a maximumenergy product of 10 MGOe with amechanical strength sufficient to allowmanipulation and assembly of indi-vidual micromagnets. We also pursuedan anisotropic form of powder, whichallows for a potential energy productof 19 MGOe. Commercial interest haspushed the fabrication of miniaturepermanent magnets down to 20-micronlinewidth with 30-micron thickness andvertical sidewall definition.

To improve the maximum energyproduct further, we investigatedmethods to achieve higher-densitysintered magnets, including hot-pressing. We found that directlypressing and sintering NdFeB powdersin the precision PMMA(polymethylmethaculate) (Plexiglas)mold did not transfer precision noryield good magnet properties. Using anintermediate mold of electroformedcopper was also unsuccessful due tothe high sintering temperatures, whichcauses yielding of the copper. There-fore, a mold material that will notdeform due to the temperatures andpressures of hot-pressing is requiredthat has prompted the possibility ofusing alumina to replicate the PMMAmold. The technique that we demon-strated is to press a ceramic (alumina)powder into a complementary PMMAmold. After burnout of the PMMA, theceramic is sintered in such a way that

it develops the required amount ofstrength for hot-press molds withoutundergoing any significant densifica-tion. In this way, the precision of themold is maintained. We obtainedincreased strength without anyshrinkage by sintering the alumina at arelatively low sintering temperaturewhere the dominant sintering mecha-nism is surface diffusion, which causesinterparticle necks to grow. We foundthese alumina molds to be strongenough to hot-press ferrite powder tofull density at 1000°C and 15,000 psiwithout breaking. Sintered MnZn-ferrite and NiZn-ferrite materials weremicromolded in this manner and haveapplications on the microscale forhigh-frequency magnetic devices. Wesuccessfully molded ferrite parts withdimensions down to 30 microns. Wehave started to use this alumina moldcoated with a thin sacrificial metal tofabricate fully dense RE permanentmicromagnets in batch. The achieve-ment of a precision ceramic mold usedin conjunction with a suitable sacrifi-cial release layer has an added benefit,which is that molding microminiatureprecision powder metallurgy–basedcomponents with a large number ofmaterials is possible, thereby dramati-cally increasing the number ofmaterials available over the currentlyavailable electroplatable metals.

Publications

Other

Christenson, T. R., T. J. Garino, and E.L. Venturini. 1998. “Deep X-RayLithography–Based Fabrication ofRare-Earth Permanent Magnets andTheir Application to Microactuators.”Proc. 5th Internat. Symp. on MagneticMater., Processes and Devices (1998ECE Meeting) (Invited).


3506.310

Agile Dry Etching ofCompound Semiconductorsfor Science–BasedManufacturing Using In SituProcess Control

C. I. H. Ashby, G. A. Vawter, J. R.Woodworth, W. G. Breiland

Compound semiconductor–basedelectronic and photonic devices are andwill continue to be critical to thefabrication of robust, versatile sensingand communications systems. Thesedevices are dependent on sophisticatedbandgap and optical-index engineering,in both the vertical and horizontaldimensions. Because of its versatility,critical dimension control, andanisotropy, the enabling tool to providehorizontal and vertical pattern forma-tion for these devices is dry plasmaetching.

To make full use of the richness ofcompound semiconductors, however,device structures are typically con-structed of a complex sequence oflayers, each with its own composition(semiconductors, metals, and insulators)and etch chemistry. Control of the etchchemistry (and its impact on etch rates,feature profile, and morphology), bothwithin a device structure and from onedevice structure to the next, is a majortechnical challenge and has been thefocus of an enormous amount of trial-and-error engineering.

In this project, Sandia willcombine advanced in situ diagnosticswith fundamental understanding ofplasma physics and chemistry toachieve an unprecedented degree ofcontrol and reproducibility over theetching process.

(1) In Situ Optical Diagnostics(a) Patterned surface reflectance

modeling. We constructed a model forreflectance from a rough surface. Thenew model departs significantly fromstandard roughness models and moreclosely describes a patterned wafer.We included interference effectsbetween surface features and sub-strate. We identified limitations of theADVISOR (Analysis of Deposition Using

Virtual Interfaces and SpectroscopicOptical Reflectance) method for roughsurfaces.

(b) Reflectance installations oninductively coupled plasma (ICP) andreactive ion beam etch (RIBE) ma-chines. We made monochromaticreflectance installations, includingsoftware, on two etch tools to allowdirect comparison between etched andas-grown structures, thereby allowingmore precise stopping on specificdevice layers. Room-temperaturewavelength-dependence studies of thereflectance of gallium arsenide (GaAs)substrates revealed unexpectedbehavior that was consistent with theevolution of thin surface films, mostlikely oxides. We analyzed the conse-quence for the determination ofsurface temperature with spectro-scopic reflectance.

(c) New methods of analysis usingdigital filter techniques. We developeddigital filtering methods to use thequalitative features in the reflectancedata to determine precise endpoints.

The first digital filter helpsidentify kinks in the reflectancespectra that occur when the opticalproperties change abruptly as a newlayer is reached during etching. Thischange is emphasized by displayingthe second derivative of the reflec-tance, which reveals layer changes asdelta-function spikes.

The second digital filter isnecessary for etching samples pat-terned with photoresist when theresist-to-exposed-semiconductor ratiois high. The strong resist signaloverwhelms the smaller semiconduc-tor signal, obscuring the etch end-point. Low-frequency oscillationsresulting from slow etching of thephotoresist and high-frequencyoscillations resulting from etching ofthe semiconductor can be separatedusing high-pass and low-pass digitalfilters.

(2) Ion Beam DiagnosticsWe used an apparatus of gridded

ion analyzers to measure mean ionenergies, ion energy distributions, ionfluxes, and ion angular distributions atdifferent positions at the waferlocation.

3506.330

Time-Resolved Ion-Beam–Induced Charge-Collection(TRIBICC) Imaging

F. W. Sexton, D. S. Walsh, P. E. Dodd, R.S. Flores, J. F. Aurand

With the continuing shrinkage ofmicroelectronic device dimensions,single-event upset (SEU) is a reliabilityconcern for space–based electronics dueto naturally occurring energetic heavyions, and for avionics and ground–basedsystems due to terrestrial cosmic rays.SEU-imaging, a technique developed atSandia’s nuclear microbeam facility,provides in situ observation of upsetlocation as a function of device opera-tional parameters. A companiontechnique, ion-beam–induced chargecollection (IBICC), measures the amountof charge arising from heavy-ion strikesas a function of position across a device.However, the rate at which charge iscollected determines upset in staticcircuits. Under this project, Sandia isdeveloping the capability to measure thecharge transients resulting from heavy-ion strikes using time-resolved IBICC(TRIBICC). TRIBICC measurements are akey to validating device-level 3-D SEUmodeling tools. This will lead to arefined understanding of charge-collection processes and an improvedestimate of the SEU sensitive volume.Improved charge-collection models willresult in increased simulation accuracy,reducing our reliance on empiricalstudies of the design space for hardeningdevices to SEU. Empirical studiesrequire variations in processing anddesign that are both expensive and time-consuming. Model–based design trade-off studies can easily be one to twoorders-of-magnitude cheaper, withmonths-to-years-shorter developmenttimes. Also, SEU-hardened devices can


be made more manufacturable byclearly understanding the trade-offsbetween SEU sensitivity, performance,and process complexity. Developingaccurate device-level simulation tools isa key element of Sandia’s stockpilestewardship mission.

We measured TRIBICC images oncomplementary metallic oxide semi-conductor 6R (CMOS6R) test struc-tures with several different ion speciesand compared results to predictions of3-D simulations. We observed goodagreement for fast-charge transientsarising from 12 MeV C, but we ob-served a large difference in thedelayed component of charge. Thisindicates a need to adjust minoritycarrier lifetimes in the model. Weobserved a significant discrepancy for28 MeV Si ions. We predicted a 2xincrease in the amplitude of fasttransients, but observed only a 0.4xincrease. We subsequently determinedthat the high-frequency preamplifiersare saturating at levels 2x lower thanspecified by the manufacturer andidentified technical solutions to thisproblem. Transients due to 5 MeV Hecould not be captured with the presentsystem because of a minimum 120 mVtriggering level for the SCD5000transient digitizer.

We improved and simplified thehardware and software. The systemnow uses the internal front-edgetriggering capability of the SCD5000transient digitizer, rather than theoriginal constant-fraction-discrimina-tor/delay-line system. The result is amore reliable and user-friendly system.We added a fast beam blankingcapability, which gives the system atrue single-ion strike capability. This isessential to eliminate the effects ofdisplacement damage on charge-collection transients. Calibration of thetest apparatus to extend its capabilityto 15 GHz will be completed this year.

Measurement of TRIBICC signalsfrom a multiple-bit memory teststructure was delayed because ofproblems with test structure designand damage to the test structureduring assembly.

Publications

Refereed

Schone, H., D. S. Walsh, F. W. Sexton, B.L. Doyle, P. E. Dodd, J. F. Aurand, R. S.Flores, and N. Wing. 1998. “Time-Resolved Ion-Beam–Induced ChargeCollection (TRIBICC) in Microelectron-ics.” IEEE Trans. on Nucl. Sci., ac-cepted.

Other

Sexton, F. W., D. S. Walsh, H. Schone, P.E. Dodd, R. S. Flores, and J. Aurand.1998. “Time-Resolved Ion-Beam–Induced Charge Collection (TRIBICC).”Proc. 11th Biennial Single-Event Effects(SEE) Symp. (Manhattan Beach, CA,20–23 March): 514–528.

3506.430

Compliant Substrates forEpitaxial Integration ofDissimilar Materials

J. A. Floro, J. Y. Tsao, D. M. Follstaedt, S.R. Lee, J. F. Klem

This project will explore apromising approach to a substrate witha continuously variable lattice constant,the so-called compliant substrate. Incollaboration with Cornell University,Sandia is focused on demonstrating andunderstanding the nature of compliancyeffects in novel twist bicrystal compliantsubstrates. These substrates differ fromthe bulk only in the presence of a twisthomointerface (created by wafer fusion)located just below the growth interface.

Sandia’s capabilities combining novel insitu diagnostics with advanced growthreactors and our expertise inheterostructure processing and proper-ties uniquely position us for success inthis area.

Preliminary growth and analysisof Si1-xGex alloys on silicon (Si)bicrystal compliant substrates indicatethat a reduction in defect density maybe associated with growth on thebicrystal, if the twist overlayer issufficiently thin. Si1-xGex alloys grownon thicker Si bicrystals exhibit stress-relaxation kinetics that are identical toalloys grown on monocrystal Sisubstrates. We fabricated patterned Sibicrystal compliant substrates tofurther evaluate the mechanisms forcompliancy. We demonstrated theabilities and limitations of x-rayreciprocal space mapping to character-ize the thickness and strain distribu-tion of as-prepared twist bicrystalcompliant substrates. We installed andare testing a Multibeam Optical StressSensor (MOSS) in our III–V molecularbeam epitaxy (MBE) chamber for real-time stress-relaxation measurementsduring indium-gallium-arsenide(InGaAs) and indium-arsenide-anti-mony (InAsSb) growth on GaAs twistbicrystal compliant substrates. Ouroverall progress was significantlyhindered by an inability to obtainconsistent, high-quality bicrystalsubstrates of either Si or GaAs. Topartially offset this problem, we areattempting to fabricate our own GaAstwist bicrystals.


3506.370

Double Quantum-Well Long-Wavelength OptoelectronicDevices

J. A. Simmons, J. R. Wendt, S. K. Lyo, J.L. Reno, S. R. Kurtz, S. Y. Lin

Sandia will research and developlong-wavelength emitters and detectorsbased on intrasubband transitions insemiconductor-coupled quantum wells(QWs). Present work on long-wave-length optoelectronics is largely basedon optical transitions across the intrinsicbandgap in the more exotic semiconduc-tors. In contrast, the unipolar quantumstructures on which we will work can befabricated in the mature aluminumgallium arsenide (AlGaAs) system.Transition energies and thus wavelengthand other properties can be tailoredacross a wide range by appropriatelyengineering the QWs and interveningbarriers. The structures can also beelectronically tuned. Bell Labs recentlydemonstrated semiconductor laserdiodes operating at 5–9 microns usingintrasubband transitions.

Our approach leverages Sandia’sinnovative processing technology,initially developed for fundamentalquantum transport experiments, torealize similar light emitters but withcertain features that should enablesuperior performance. In addition to theapplication of novel processing technol-ogy, we will explore alternativeintrasubband transitions.

Because the nature of lightemission and detection in these devicesis substantially different from that inconventional lasers and detectors, thisresearch provides rich opportunities forinvestigating fundamental phenomena,including tunneling, phonon-mediatedrelaxation processes, and electronicstates in artificially structured materials.The knowledge gained will be valuablefor both quantum and classical micro-electronics and photonics. The workalso exercises existing compoundsemiconductor fabrication techniques

and drives the development of newcapabilities for processing long-wave-length waveguide geometry devices.

The primary goal of this project isto develop room-temperature, long-wavelength, semiconductor emittersand/or detectors that will be directlyrelevant to requirements for sensing andother applications. Semiconductor lasersshould offer a variety of benefits forsystems in terms of functionality. Mid-infrared (mid-IR) lasers and detectorscan be used for chemical analysis andthermal detection. Electronic tunabilityand narrowband operation are particu-larly attractive for spectroscopicsystems.

We performed extensivephotoresponse measurements ofdouble quantum-well (DQW) detectorsin a free-electron laser. We observed anarrowband photoresponse and alsosaw indications of gate tunability. Wedetermined that we needed newsamples with smaller, electron-beam-written gates and faster resistance-capacitance (RC) response times, andalso larger energy subband offsets,which we designed, grew, and fabri-cated. Electrical measurementsshowed excellent behavior, with largeresonances visible at 77°K. Thesesamples are now being opticallymeasured in the free-electron laser. Wealso developed a gate insulationprocessing technique that greatlyincreased our yield by preventing theshorting of backgates to frontgates, afailure mode that appeared in morethan half of our samples. We designed,grew, and measured laterally contactedtriple QW light emitters and measuredtheir electrical characteristics quiteextensively. We are currently measur-ing the emission of these structures ina spectrometer, and have grown andare fabricating a new generation ofsimilar triple-well emitters havingthicker tunneling barriers to make thegate-induced energy subband lineupseasier, and also some new four-wellemitter structures. Finally, we initiateda collaboration with researchers at

MIT on stacked triple-well terahertzemitters. MIT has already seennarrowband emission at 14 meV andhas performed extensive transition-rate calculations. We plan new struc-tures using our epoxy-bond-and-stop-etch (EBASE) flip-chip technique toachieve better mode confinement bysurface metal on both sides, in thehopes of achieving lasing, and arelooking at shorter-wavelength single-cell structures that would be electri-cally tunable via surface gates.

Publications

Refereed

Peralta, X. G., S. J. Allen, S. Y. Lin, J. A.Simmons, M. A. Blount, and W. E. Baca.1998. “Photoconductive Response ofDouble Layer Quantum Wells inIntense Terahertz Electric Fields.”Paper presented to the 20th Interna-tional Free Electron Laser Conference,Williamsburg, VA, 16–21 August.

Simmons, J. A., J. S. Moon, M. A.Blount, J. L. Reno, X. G. Peralta, and S.J. Allen. 1998. “The Double ElectronLayer Tunneling Transistor (DELTT).”Paper presented to the Future Trendsin Microelectronics Workshop, Ile desEmbiez, France, 31 May–5 June.

Simmons, J. A., J. S. Moon, M. A.Blount, S. K. Lyo, V. M. Hietala, J. L.Reno, R. Lake, X. G. Peralta, S. J. Allen,P. J. Burke, and J. P. Eisenstein. 1998.“Development of the Double ElectronLayer Tunneling Transistor (DELTT)for Electronics and Optical Applica-tions.” Paper presented to the DARPAUltra Electronics Program Review,Estes Park, CO, 18–21 October.

Other

Peralta, X. G., S. J. Allen, S. Y. Lin, J. A.Simmons, M. A. Blount, and W. E. Baca.1998. “Photon-Assisted ResonantTunneling and 2-D Plasmon Modes inDouble Quantum Wells in IntenseTerahertz Electric Fields.” Bulletin ofthe Amer. Phys. Soc. 43 (Los Angeles,CA, 16–20 March): 554.


3506.350

Role of Defects in III-Nitride–Based Electronics

J. Han, S. M. Myers, Jr., A. F. Wright, R. J.Shul, C. H. Seager, M. H. Crawford, A. G.Baca

Wide-bandgap III-nitride semicon-ductors are extremely promisingmaterials for the compact, high-power,high-frequency amplifiers required forfuture satellite cross- and up-/downlinks,and for the robust microelectronicsrequired for future severe-environmentnational security applications. Inaddition, they have the potential toenable a new generation of optoelec-tronic devices in the visible andultraviolet (UV) spectral regions. Theultimate realization of high-performanceGaN–based devices is presently limitedby the high density of defects and thecomplex microstructure of the galliumnitride (GaN) materials, both of whichinterfere with the intrinsic materialsproperties. This project is intended toprovide a scientific base for understand-ing the role of defects in GaN. Ourapproach can be categorized into threeparts: (1) establishing a strongmetalorganic chemical vapor deposition(MOCVD) growth capability for III-nitridematerials that we will apply to study andcontrol microstructural evolution andgrowth parameter-dependent defectformation, (2) applying various micro-scopic probes (some unique to Sandia)and bulk characterization techniques tostudy defects in GaN and determine theireffects on electronic and opticalproperties, and (3) performing state-of-the art first-principles calculations of theenergetics of defects and defect com-plexes in III-nitride alloys.

We significantly enhanced theMOCVD growth capability. Startingfrom the growth of GaN films, weexplored and demonstrated both n-type and p-type doping of GaN as wellas aluminum gallium nitride (AlGaN)

alloys. We demonstrated an electronconcentration of up to 5e18 cm-3 forAL0.25Ga0.75N. We reproduciblyachieved free-hole concentrationsexceeding 5e17 cm-3. We characterizedthese materials using low-temperaturephotoluminescence (PL), high-resolution x-ray diffraction, x-rayreciprocal mapping, and Hall measure-ments. These materials growthadvances were critical to enable ourstudies on the interaction of defectswith dopants as well as the microstruc-ture and defects of AlGaN alloys. Wethoroughly examined the role ofhydrogen (H) in GaN, including thestate, transport, and microstructuraleffects of H, through post-growth ion-implantation studies. We found strongattachment of H to nitrogen (N)dangling orbitals, which is favorablefor passivation of defects. In addition,we determined the permeability of H inGaN for the first time. In the area oftheoretical modeling, we went beyondsingle-point defect calculations andperformed first-principles calculationsof the energetics of various structuraldefects, including stacking faults anddislocations in GaN and AlN. Thecalculations revealed that the corestructure of an edge dislocation in GaNdepends critically on the Fermi level inthe material and would therefore bedifferent for n-type and p-type GaN.Furthermore we used density-func-tional theory (DFT) to determine thesolution sites for hydrogen in a perfectcrystal (without defects) as a prerequi-site for studying its interaction withdefects.

Publications

Refereed

Han, J., J. J. Figiel, M. H. Crawford, M.A. Banas, M. E. Bartram, and R. M.Biefeld. 1998. “MOVPE Growth andGas-Phase Reactions of AlGaN.” Paperpresented to the 9th InternationalConference on MOVPE, LaJolla, CA, 4June.

Han, J., J. J. Figiel, M. H. Crawford, M.A. Banas, M. E. Bartram, and R. M.Biefeld. 1998. “MOVPE Growth andGas-Phase Reactions of AlGaN for UVEmitters.” J. Crystal Growth, accepted.

Han, J., T. B. Ng, R. M. Biefeld, M. H.Crawford, and D. M. Follstaedt. 1997.“The Effect of H2 on MorphologyEvolution During GaN MOCVD.” Appl.Phys. Lett. 71 (24 November): 3114.

Myers, S. M., J. Han, T. J. Headley, C. R.Hills, G. A. Petersen, C. H. Seager, andW. R. Wampler. 1998. “Ion-ImplantedHydrogen in Gallium Nitride.” Nucl.Instr. and Meth. in Phys. Res. B, ac-cepted.

Ng, T. B., J. Han, R. M. Biefeld, J. C.Zolper, M. H. Crawford, and D. M.Follstaedt. 1998. “The Effect of H2

Carrier Gas on the MorphologicalEvolution and Material Properties ofGaN on Sapphire.” Proc. Mater. Res.Soc. Symp. 482 (May) (Boston, MA, 1December 1997): 143.

Seager, C. H., S. M. Myers, G. A.Petersen, and J. Han. 1998. “Trappingof H in Ion-Implanted GaN.” Paperpresented to the Spring MRS Meeting,San Francisco, CA, 13 April.

Seager, C. H., S. M. Myers, G. A.Petersen, J. Han, and T. Headley. 1998.“Infrared Studies of Ion-Implanted H inGaN.” J. Appl. Phys.

Wright, A. F. 1997. “TheoreticalInvestigation of Extended Defects inGroup-III Nitrides.” Proc. Mater. Res.Soc. Symp. 482 (Boston, MA, 4 Decem-ber): 795.

Wright, A. F., and U. Grossner. 1998.“The Effect of Doping and GrowthStoichiometry on the Core Structure ofa Threading Edge Dislocation in GaN.”Appl. Phys. Lett. (9 November).


3506.340

Composite-ResonatorSurface-Emitting Lasers

K. D. Choquette, B. E. Hammons, K. M.Geib, A. A. Allerman, W. W. Chow

Applications of vertical-cavitysurface-emitting lasers (VCSELs) haverequirements ranging from amplitudemodulation, frequency tunability, andamplitude or frequency stability, to highoutput power. The present single-resonator VCSEL lacks the agility toreadily perform many of the abovefunctions. Sandia will use compositeresonators to control spectral andtemporal properties of VCSELs. Thisstructure in effect is a coupled-resonatorvertical-cavity laser (CRVCL). Usingcomposite resonators opens up newpossibilities because of their uniqueability to (1) tailor the coupling betweenthe monolithic cavities, (2) dynamicallymodify the cavity interaction, and (3)incorporate passive or active resonatorsthat are spectrally degenerate ordetuned. Composite resonators can beutilized to influence the spectral andtemporal properties within a VCL. Thecomposite resonator will consist of aprimary resonator containing the gainsection and an active or passivesecondary resonator. Separate contactsprovide independent current injectioninto the resonators. The couplingbetween the resonators is controlled bythe transmission of the shared distrib-uted Bragg reflector (DBR). We will usedifferent configurations of a monolithiccomposite-resonator surface-emittinglaser structure to demonstrate (1)amplitude modulation, (2) gain-switching, and (3) frequency tuning. Thelatter will allow fine-tuning of the mode/gain alignment after growth to compen-sate for temperature and injectioncurrent fluctuations. Successful demon-stration of the above functions will be amajor step toward making VCSELtechnology viable for many defense andcommercial applications.

Our accomplishments this yearinclude the following:

(1) Developed detailed coupledresonator optical model and identifiedcavity length tuning and mode-lockingas two viable methods of amplitudemodulation.

(2) Demonstrated large singlemodulation up to 50 MHz (apparatuslimited) using cavity length tuning viacurrent injection into the passivecavity. Using current injection into thepassive cavity depresses the index andthus optical path length in the passivecavity, leading to a decrease in lightoutput. We determined that the mostefficient modulation using forwardinjection current into the passivecavity is achieved when the activecavity is biased at its maximum outputpower.

(3) Demonstrated large singlemodulation up to 50 MHz (apparatuslimited) using mode-locking byreverse-biasing the passive cavity.

(4) Developed many-bodyanalysis of quantum-well (QW) gainregion and are incorporating this intooptical coupled-resonator model toanalyze gain-switching.

(5) Are developing short-pulsecharacterization based in an opticalstreak camera system to probe thegain-switching of coupled-resonatorVCSELs on the picosecond time scale.

(6) Are developing a suitabledevice topology and required masks tofabricate coupled-cavity VCSELs forshort-pulse and high-speed modulationcharacterization.

Publications

Refereed

Choquette, K. D., H. Q. Hou, W. W.Chow, K. M. Geib, and B. E. Hammons.1998. “Composite-Resonator Vertical-Cavity Laser Diode.” Proc. Conf. onLasers and Electro Optics ’98 (CLEO ’98)(San Francisco, CA, May): 567.

Choquette, K. D., W. W. Chow, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Vertical Coupled-Cavity Surface-Emitting Laser Diodes.” Proc. DeviceRes. Conf. ’98 (Charlottesville, VA,June): 67.

Other

Choquette, K. D., W. W. Chow, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Coupled-Resonator Vertical-Cavity Laser.” Proc. SPIE, Vertical-CavitySurface-Emitting Lasers II 3286 (SanJose, CA, January): 45–49.

3506.360

Ultra–Low-Power Sensors forMicrotelemetry Systems

R. C. Hughes

Sandia will design, fabricate, andtest ultra–low-power sensors that arecapable of being powered and read outby analog circuits that are, in turn,capable of coupling the sensor informa-tion to radio frequency (RF) telemetry.The microelectrochemical cell (MEC) isa key enabling technology for a widevariety of chemical sensors in thesensor/tag combination and opens thedoor to new applications in sensing forcounterproliferation, weapon monitor-ing, and many other areas. The currentstate of electronic tagging circuits iseffective for grain-of-rice– to jelly-bean–sized chips that can be remotelypowered, programmed, and read out.The first new sensors to be used in thisproject are polymer film composites withmetal powders. They conduct bypercolation, and swelling of the polymercauses an increase in film resistance. Asecond kind of chemiresistor filminvolves the conductivity of ions andhow that is affected by various analytes.A considerable literature onelectroactive chemically sensitive filmshas developed over the last few years,and Sandia has the technology tocombine the tagging electronics withthese low-power electrochemicalsensors. Issues to be resolved includethe quality and type of data to betransmitted, how to handle analog datafrom the sensor as well as ultra–low-power management, and the range ofoperation. Other technical issues wouldinvolve the levels of voltage and chargerequired to obtain a reliable read-out.We also envisage ultra-small versions ofthe radioactive field-effect transistor(radFET) and hydrogen sensor thatrequire only a small number of cou-lombs.

A matchbox-sized telemetrysystem using commercial RF compo-nents with voltage input from one ofour chemiresistors allowed the sensingof a volatile organic chemical (VOC) tobe transmitted through the buildingwalls to an office computer some 50feet away. We fabricated many new


chemiresistors from a variety ofpolymer/metal powder compositesand measured their response to avariety of VOCs. We developed theconcept of a universal solvent sensorarray using the solubility parameterapproach for both polymers andsolvents. Because our sensor arraygives signals for solvents representingthe extremes of solubility parameters,we believe that no solvent will goundetected by this array. In addition todetecting solvent vapors, we showedthat the individual vapors can beidentified by the array, independent oftheir concentration, by using patternrecognition (PR) techniques. We alsomade progress in identifying the twocomponents in binary mixtures ofunknown concentration. This isparticularly important in field usewhen one of the unknowns is watervapor. We also used impedancespectroscopy to gain new insight intomechanisms of response of solidelectrolyte sensors. The low-frequencyimpedance is dominated by polariza-tion effects that depend in detail onthe analyte molecules. We filed atechnical advance for using thistechnique to identify analytes. We alsofabricated a new substrate withelectrodes for four chemiresistors(four terminal), two heaters, and a Pt/Ti temperature sensor. This array isabout 1 square centimeter and fits in astandard 16-pin dual in-line package(DIP). We demonstrated that achemiresistor on one set of electrodesworks along with the heater andtemperature sensor. This chip, alongwith a signal-processing chip, will formthe goals of next year’s work, demon-strating an extremely small, low-powersensor system.

Publications

Refereed

Hughes, R. C., M. P. Eastman, W. G.Yelton, A. J. Ricco, S. V. Patel, and M.W. Jenkins. 1998. “Application of theSolubility Parameter Concept to theDesign of Chemiresistor Arrays.” Tech.Digest 1998 Solid-State Sensors andActuators (Hilton Head, SC, June): 379–382.

3506.380

The Development ofIntegrated ChemicalMicrosensors in GaAs

S. A. Casalnuovo, S. L. Hietala, A. G.Baca, V. M. Hietala, J. L. Reno, R. J.Kottenstette, G. C. Frye-Mason, E. J.Heller

By taking advantage of both thepiezoelectric and semiconductingproperties of gallium arsenide (GaAs),Sandia will fabricate arrays of acoustic-wave chemical microsensors integratedwith microelectronic drive and outputcircuitry on a single GaAs substrate,resulting in a compact, extremely low-power, highly sensitive chemical-detection system capable of discriminat-ing among large numbers of liquid andgaseous chemicals. GaAs has severaladvantages in this application. Itspiezoelectric coefficient is comparableto that of quartz, the standard materialfor acoustic resonator chemical sensors.High-frequency (nominally 1 GHz)resonator microelectronics are easilyfabricated in GaAs using existing GaAsmicrofabrication technology and areprocess-compatible with GaAs acousticdevices. Selective etching of GaAs andaluminum gallium arsenide (AlGaAs)epitaxial films makes possible thefabrication of thin (typically 1 to 10microns) piezoelectric membranes,nominally 100 microns in diameter,capable of high-sensitivity (1femtogram) detection. No other piezo-electric material can support theintegrated microelectronics nor producethe thin-film resonators. No othersemiconductor, particularly silicon (Si),is piezoelectric, and fabrication processincompatibilities make the integration ofSi and piezoelectrics difficult.

We produced the first functionalmonolithically integrated GaAs surfaceacoustic-wave (SAW) delay lineoscillators for chemical-sensingapplications. This device comprises aGaAs integrated circuit (IC) amplifierand a GaAs SAW delay line fabricated

on the same substrate. It is small (2mm2) and low power (60 mW, operat-ing at 3 V). We also fabricated a hybridGaAs SAW oscillator using a Sandia-designed, commercially fabricated ICamplifier and a Sandia-fabricated GaAsSAW delay line. We demonstratedchemical detection with this device.We designed, fabricated, and testedfunctional phase comparator ICs.When integrated with the oscillators,this will produce a complete dc-in, dc-out chemical microsensor.

We demonstrated the first GaAsmembrane flexural plate-wave (FPW)acoustic delay lines, using micro-machining techniques we developedpreviously. These devices havepotentially higher sensitivity thanconventional SAW sensors and havethe additional advantage of operationin liquids.

We developed multi-elementarrays of SAW delay lines on a singleGaAs chip, making possible thedetection of numerous chemicalspecies with a single sensor.

We demonstrated a temperature-compensated GaAs SAW delay line,thereby eliminating one of the princi-pal disadvantages of GaAs sensorswhen compared to conventionalquartz sensors.

We fabricated and tested a GaAsIC phase comparator that converts thehigh-frequency output of the GaAsSAW oscillator sensor to a dc signal.This device has a sensitivity of 6 mV/degree at 500 MHz, operates at 3 V, anddraws 27 mW.

Publications

Other

Casalnuovo, S. A., E. J. Heller, V. M.Hietala, A. G. Baca, R. Kottenstette, S.L. Hietala, J. L. Reno, and G. C. Frye-Mason. 1998. “Acoustic-Wave ChemicalMicrosensors in GaAs.” Proc. SPIE,Micromachined Devices and Compo-nents IV, Micromachining andMicrofabrication Symp. 3514 (SantaClara, CA, 21–22 September): 103–110.


3506.410

Monolithic Integration ofVCSELs and Detectors forMicrosystems

K. D. Choquette, B. E. Hammons, J. A.Nevers, K. M. Geib, A. A. Allerman, M. E.Warren

Vertical-cavity surface-emittinglasers (VCSELs) are high-efficiency lightsources appropriate for microsystemapplications that will benefit frommonolithic integration with compatiblephotodetectors. Such an integration offunctions has applications ranging fromnear-term use in monitors for suretydevices to longer-term enabling of on-chip photonic interconnects andadvanced microsystems for sensing,surety, data storage, data routing,communication, and image manipula-tion, processing, and transmission.Moreover, 2-D arrays are an importantextension of VCSEL technology, andintermeshed VCSEL/detector arrays willenable numerous advanced applica-tions. Approaches for VCSEL/photode-tector integration include the applicationof metal-semiconductor-metal (MSM)detectors on the laser substrate and thecreation of resonant-cavity photodetec-tors (RCPDs) using the VCSEL epitaxiallayers. Note that the detectors could bethe same as the VCSEL wavelength, orbe designed at different wavelengthsusing wafer-bonded detector material.An array of the latter would provide themeans of image intensification or imageconversion, e.g., for infrared viewing.This project will address the basicenabling technologies for theseapproaches and will use combinationsof these approaches to create exampleprototypes that are designed to demon-strate the ability to enable new applica-tions. In addition, this project willinclude environmental testing (radiationand high temperature) of these devicesunder conditions appropriate forinternal DOE applications as well asexternal applications, such as opto-

couplers in spacecraft targeted for outerplanetary systems.

We made the following accom-plishments this year:

(1) Developed integrated VCSELsand RCPDs. This required the design ofsuitable masks and an appropriatedevice fabrication process. We laid outnumerous different RCPD structuresand geometries and characterizedthem for high-temperature and high-radiation environments that are ofinterest to internal programs and tothe Jet Propulsion Laboratory forspace opto-couplers.

(2) Characterized the photocur-rent response of RCPD illuminated byneighboring VCSEL. In this experiment,we suspended a mirror over the chipto reflect the output from the mono-lithic VCSEL into the neighboringdetector. The laser threshold wasclearly exhibited in the photodetectorcurrent. As the VCSEL becamemultimoded, the detector responseshowed some structure above thresh-old due to changes in the reflected far-field VCSEL beam. In addition, thephotocurrent fell off faster than thelaser output because of the spectralshift of the laser emission beyond thespectral acceptance of the photodetec-tor.

(3) Characterized the spectralresponsivity of RCPDs. We achieved apeak responsivity of 0.8 W/A using a 9V reverse bias. We also identified keymaterial issues for improved photode-tector response.

(4) Used preliminary character-ization of VCSELs under high-energycharged-particle radiation to demon-strate self-repair during post-radiationlaser operation. Thus the radiationhardness of VCSELs appears verypromising.

(5) Constructed a 16-board (128-device) automated VCSEL lifetimetesting system.

(6) Operated eight selectivelyoxidized VCSELs at 1 mW outputpower over 20,000 hours at 80°C withonly a single device failure.

Publications

Refereed

Choquette, K. D., and H. Q. Hou. 1998.“Vertical-Cavity Surface-EmittingLasers: Moving from Research toManufacturing.” Proc. IEEE (Invited) 85(October): 1730–1741.

Choquette, K. D., A. A. Allerman, H. Q.Hou, K. M. Geib, and B. E. Hammons.1998. “Applications and Performanceof VCSELs.” Paper presented to the1998 GaAs IC Symposium (Plenary),Atlanta, Georgia, November.

Choquette, K. D., H. Q. Hou, K. M. Geib,and B. E. Hammons. 1997. “UniformSelectively Oxidized Two-DimensionalVCSEL Arrays for VLSI Photonics.”Proc. 1997 Lasers and Electro Optics(LEOS) Ann. Mtg. (San Francisco, CA,November): 335.

Choquette, K. D., H. Q. Hou, K. M. Geib,M. H. Crawford, and B. E. Hammons.1997. “High-Performance SelectivelyOxidized Vertical-Cavity Laser Arrays.”Proc. 44th Nat. Symp. Amer. Vac. Soc.(Invited) (San Jose, CA, October): 246.

Paxton, A. H., R. F. Carson, H. Schone,E. W. Taylor, K. D. Choquette, H. Q.Hou, K. L. Lear, and M. E. Warren. 1997.“Damage from Proton Irradiation ofVertical-Cavity Surface-EmittingLasers.” IEEE Trans. Nucl. Sci. 44(December): 999.

Pu, R. E. M. Hayes, C. W. Wilmsen, K. D.Choquette, H. Q. Hou, and K. M. Geib.1997. “VCSELs Bonded Directly toFoundry-Fabricated GaAs Smart PixelArrays.” IEEE Photon. Tech. Lett. 9(March): 1622–1624.

Other

Choquette, K. D., H. Q. Hou, K. M. Geib,and B. E. Hammons. 1997. “Low-Threshold InGaAs Selectively OxidizedVertical-Cavity Lasers.” Proc. 1997 OSAAnn. Mtg. (Long Beach, CA, October):423.


3506.420

AlGaN Materials Engineeringfor Integrated MultifunctionSystems

J. Han, M. H. Crawford, D. M. Follstaedt,R. J. Shul, S. A. Casalnuovo, J. G.Fleming, S. R. Lee, T. J. Drummond

In response to a world-wideinterest in wide-bandgap III-nitridedevices and the recent progress in thedevelopment of metalorganic chemicalvapor deposition (MOCVD) growth ofaluminum gallium nitride ([Al,Ga]N)materials at Sandia, we are exploringthe multifunctional usage of thesesemiconductor alloys to meet variousmission requirements and to positionSandia at the technological forefront ofthis strategically important materialfamily. Over a wide range of possibleapplications, we identified the develop-ment of compact ultraviolet (UV)optoelectronic devices (emitters anddetectors), piezoelectric devices(surface acoustic-wave [SAW] sensors),and the integration of GaN with silicon(Si) as the initial thrust areas. All ofthese areas have thus far remainedrelatively unexplored and yet are wellaligned with Sandia’s mission objec-tives. In addition to maintaining a broadportfolio, this project will explore the fullpotential of the ceramic-like nature ofthe III-nitride materials (namely, thephysical robustness, chemical inertness,and tolerance to structural defects) toachieve chip-level integration intomicrosystems containing various nitridedevices and possibly between nitridedevices and Si–based electronics. Our

work in the first year included thedemonstration of UV GaN/AlGaNquantum-well (QW) light-emitting diodes(LEDs) at 354 nm, initial demonstrationof the first 200 MHz GaN SAW delaylines, and substantial progress in theintegration of GaN with Si(111) sub-strates as well as Si(100) surfacesthrough the use of silicon-on-insulator(SOI) structures.

We laid down a solid foundationin the growth and application of(Al,Ga)N alloys. The MOCVD growthoperation evolved from the initialphase of materials exploration into astage where both device demonstra-tions and scientific investigations canbe routinely supported. In terms of thegrowth of III-nitride materials, wedemonstrated both n-type and p-typedoping of GaN. We grew and character-ized up to 45% Al-containing AlGaNalloys and GaN/AlGaN QW hetero-structures. We successfully combinedour new ability to achieve bipolardoping and GaN/AlGaN hetero-structures to achieve the furtherdemonstration of GaN/AlGaNmultiquantum-well LEDs emitting at354 nm. We believe this device resultto be quite significant, as we believe itis the shortest-wavelength QW LEDreported to date, and the UV emissioncan be applied to a number of sensorand illumination applications. We fileda technical advance on the UV LEDdesign and performance.

We also investigated the growthof GaN on different Si surfaces ([111],[100], and Si dioxide). In particular, weverified the unique and crucial role ofthe Si(111) surface in providing a

hexagonal template for the growth ofGaN. We prepared novel SOI structuresto investigate the feasibility of inte-grated GaN with (100)Si surfaces.Initial evidence suggests that theinsertion of a thermal oxide layertends to alleviate the tensile stress andreduce the cracking density in Siwafers. Finally, we successfullyfabricated the first 200 MHz GaN SAWdelay lines.

Publications

Refereed

Han, J., J. G. Fleming, and D. M.Follstaedt. 1998. “MOCVD Growth ofGaN on Silicon and Related Surfaces.”Proc. Mater. Res. Soc. Symp. 512 (SanFrancisco, CA, 31 March–4 April): 53–58.

Han, J., J. J Figiel, M. H. Crawford, M. A.Banas, M. E. Bartram, and R. M.Biefeld. 1998. “MOVPE Growth andGas-Phase Reactions of AlGaN for UVEmitters.” Paper presented to the 9th

International Conference of MetalOrganic Vapor Phase Epitaxy, La Jolla,CA, 30 May–4 June.

Han, J., J. J Figiel, R. M. Biefeld, and M.H. Crawford. 1998. “Gas-Phase Reac-tions During MOCVD Growth AlGaN.”Paper presented to the 40th ElectronicMaterials Conference, Charlottesville,VA, 23–26 June.

Han, J., M. H. Crawford, R. J. Shul, J. J.Figiel, M. Banas, L. Zhang, Y. K. Song,H. Zhou, and A. V. Nurmikko. 1998.“AlGaN/GaN Quantum-Well UltravioletLight-Emitting Diodes.” Appl. Phys. Lett.73 (September): 1688–1690.


3506.440

Post-Processed IntegratedMicrosystems

R. J. Shul, K. O. Wessendorf, W. K.Schubert, S. A. Casalnuovo, S. H.Kravitz, T. R. Christenson

Sandia will develop a low-costplatform for integrated microsystemsthat is easily configured to meet a widevariety of specific applications-drivenneeds. Once developed, this platform,which incorporates many of the ele-ments that are common to numerousmicrosystems, will provide integratedmicrosystem users with access to thistechnology without paying the highupfront development costs that are nowrequired. The process starts with thefabrication or acquisition of wafers ofsparsely placed device or circuitcomponents fabricated in any foundriedtechnology (silicon [Si] complementarymetal oxide semiconductor [CMOS] orbipolar technologies, high-frequencygallium-arsenide (GaAs) technologies,microelectromechanical systems[MEMS], etc.). We call these smartsubstrates. Using Sandia’s diverseprocessing capabilities, we then intendto post-process high-value componentsin open areas on the front or the back ofthe wafers and microelectronicallyintegrate the added components with thepreplaced circuitry. Examples of post-processed components include sensors,antennas, surface acoustic-wave (SAW)devices, passive elements, microoptics,and surface-mounted hybrids. The

combination of preplaced electronicsand post-processed components willenable the development of many newtypes of integrated microsystems.Targeted applications include integratedsensored systems, tags, and electrome-chanical systems.

(1) We developed and integratedseveral microelectronic fabricationprocesses into the post-processing ofsmart substrates. Processes includethin-film metallization, low-stresssilicon nitride (SiN), thermal oxide,front- and backside contactlithography, and a deep high-aspect-ratio Si etch (HARSE).

(2) We developed and optimizeda HARSE process, which enabled thefabrication of a variety of Si structureswhere deep trench etching is neces-sary. We demonstrated high Si etchrates, ranging from 1 to 3.5 µm/minute,with highly anisotropic profiles andsmooth etch morphologies. TheHARSE process operates at roomtemperature and yields etch selectivi-ties of Si to resist > 100:1 (eliminatingthe need for hard masks), Si to Sidioxide (SiO2) ~ 275:1, and Si to SiN~ 85:1, thus enabling the fabrication ofmembrane–based devices.

(3) We demonstrated the HARSEprocess for many device applications,including a fundamental mode mag-flexural plate-wave (FPW) device,micromachined heater, device locator,post-processing of MEMS devices, anda locating assembly to support andalign corresponding LIGA (German forlithography, electroforming, and

molding)-fabricated mechanicalcomponents. LIGA gear trains used anarray of 150-micron-diameter by320±micron-tall pins, which wereetched into a Si wafer using the HARSEprocess. In addition, we successfullydemonstrated an FPW–based transmit-ter/receiver at atmospheric pressurewith a 1 mm-diameter SiN membrane.

(4) We demonstrated post-processing capability on an integratedGaAs chemical microsensor thatmonolithically integrates a SAWsensor, a high-frequency amplifier, anda frequency-converter output stage.We also demonstrated post-processingon MEMS discriminator wheels andpop-up mirrors. We aligned vias to thefrontside structures and etched usingthe HARSE process.

(5) We demonstrated post-processing capability on a MEMScounter-meshing gear discriminator.Unreleased MEMS structures werepost-processed using the HARSEprocess to etch vias through 400 to 600microns of Si. We then released theMEMS structures and used them totransmit light through the Si substrate.

Publications

Refereed

Shul, R. J. 1998. “Selective, Deep SiEtching with Dimensional Control.”Proc. SPIE, Micromachining andMicrofabrication Process Technol. IV3511 (Santa Clara, CA, 21–22 Septem-ber): 252–261.








PHENOMENOLOGICAL

MODELING &

ENGINEERING

SIMULATION

The driving force for this area is the Revolutionin Engineering, a vision in which the life-cycleengineering process occurs within a pervasive,validated simulation environment. Research seeks todevelop computer models that predict if and why acomponent will fail, projects that describe how aproduct will perform under various operatingconditions, and projects that enhance or expand useof the Sandia teraflops computer. Success in thisvision will require unprecedented levels of confidencein computer simulation. Six key research areas support this effort: (1)increased model fidelity that requires the developmentof a computer model that will contain sufficientresolution to allow for predictions of product failure,(2) improved high-performance computing solutionsthat operate across platforms, (3) performance ofuncertainty quantification rigorous enough to quantifythe validity of the simulation, (4) experimentaldiscovery to enable high-fidelity models, (5) validationof the computer algorithms and codes byexperimentation, and (6) development of diagnosticsnecessary to ensure the success of the experiments. Comprehending the behavior of a material re-quires understanding the process of heat and masstransfer. These transfers, or flows, can be studied foreither fluid or thermal events. Fluid material flowsinclude the movement of fluids such as water and oil,or of molten solids such as liquid metals. Thermalflow studies examine the way heat is transferredthrough a specific material. A Sandia project developedan advanced computational framework forinvestigating the fundamental phenomenacharacterizing complex 3-D flows. Lattice Boltzmann (LB) is a kinetic theory–basedmethod that forms the basis for this research. BecauseLB methods are explicit in time and space, they areideally suited for modeling these complex heat- andmass-transfer processes. This research will make it possible to use compu-ter modeling to understand and predict heat andmass transport in complex materials such as porousmedia. Sandia developed a distributed computationalplatform based on commercial off-the-shelf computercomponents that is capable of production-scale LBsimulations. Applications for this product abound inthe geosciences, materials science, and chemical,thermal, and mechanical engineering.

Sandia National Laboratories/LDRD FY 1998 Annual Report 79Sandia National Laboratories/LDRD FY 1998 Annual Report 79




3508.060

Enhanced Vapor-PhaseDiffusion in Porous Media

S. W. Webb, C. K. Ho

Vapor-phase diffusion in porousmedia may significantly impact manyimportant applications. Examplesinclude the drying of sol-gel coatings andtextiles, agricultural processes, and thetransport of chemicals such as TNT fromburied landmines. Vapor-phase diffusionmay also be important in gas transportat high-level nuclear-waste repositories.In addition, in many environmental-remediation and waste-isolationapplications, such as the removal ofnonaqueous phase liquid (NAPL)contaminants from low-permeabilitylayers in the subsurface, vapor-phasediffusion is the limiting transportmechanism. Enhancement of vapor-phase diffusion by up to several ordersof magnitude has been postulated, butnot directly measured, in the presence ofits liquid through local pore-scalecondensation and evaporation at vapor-liquid interfaces. The objective of thepresent work is to resolve criticalprocesses and questions associated withpostulated enhanced vapor-phasediffusion mechanisms. The approachtaken in the present research is toperform modeling and experimentalinvestigations of enhanced vapor-phasediffusion in porous media at variouslength scales, including the pore scaleand the laboratory scale.

Results of this investigationinclude the first direct measurements ofsignificant enhancement of vapor-phasediffusion at the pore scale and at thelaboratory scale. We developed the firstmechanistic pore-scale model ofenhanced vapor-phase diffusion. Theresults from this model and the pore-scale experiments are in agreement witheach other. Therefore, we have defini-tively answered the question concerningthe existence of enhanced vapordiffusion (EVD). EVD does exist asdirectly measured and mechanisticallymodeled for the first time.

Our accomplishments in thisproject included the completion of themodeling and experimental investiga-tions.

(1) Modeling• We calculated pore-scale

modeling results for numeroussituations. We investigated transientdrying conditions; the results aresimilar to steady-state conditions if theproper scaling is employed. Wecalculated the effect of concentrationand temperature gradients on EVD.EVD is predominantly driven byconcentration gradients; any tempera-ture gradient is a secondary factor.These results are supported in acollaboration with New Mexico Techand are contrary to the standardmodel of Philip and deVries, whoassumed that a temperature gradientwas the only driving force. Therefore,the Philip and deVries model needs tobe modified to reflect these findings.

• Continuum modeling resultsshow that EVD is necessary to predictthe vapor diffusion rate in a partiallysaturated packed bed. If EVD isignored, the model predictions do notagree with the data.

(2) Experiments• Innovative pore-scale experi-

ments were designed and conducted atNew Mexico Tech. These experimentsshow significant enhancement of vapordiffusion due to pore-scale liquidisland processes, in agreement withpore-scale modeling studies.

• Porous media experimentsusing a bed of glass beads werecompleted at Washington StateUniversity. These results also confirmthe existence of EVD.

(3) OverallWe performed the first direct

measurements of EVD and developedthe first mechanistic pore-scale modelof EVD. Both of these efforts demon-strate conclusively that EVD exists andis a potentially important transportmechanism in porous media.

Publications

Refereed

Gu, L., C. K. Ho, O. A. Plumb, and S. W.Webb. 1998. “Diffusion with Condensa-tion and Evaporation in PorousMedia.” Proc. 7th AIAA/ASME JointThermophys. and Heat Trans. Conf. 357-2 (Albuquerque, NM, 14–18 June): 213–220.

Gu, L., C. K. Ho, O. A. Plumb, and S. W.Webb. 1998. “Vapor Diffusion inPartially Saturated Packed Beds.” Proc.1999 ASME/JSME Thermal Engin. JointConf., accepted.

Ho, C. K., and S. W. Webb. 1998.“Review of Porous Media EnhancedVapor-Phase Diffusion Mechanisms,Models, and Data—Does EnhancedVapor-Phase Diffusion Exist?” J. PorousMedia 1 (January): 71–92.

Webb, S. W. 1998. “Gas-Phase Diffusionin Porous Media—Evaluation of anAdvective-Dispersive Formulation andthe Dusty-Gas Model for BinaryMixtures.” J. Porous Media 1 (March):187–199.

Webb, S. W. 1998. “Pore-Scale Modelingof Transient and Steady-State VaporDiffusion in Partially-Saturated PorousMedia.” Proc. 7th AIAA/ASME JointThermophys. and Heat Trans. Conf. 357-2 (Albuquerque, NM, 14–18 June): 221–231.

Webb, S. W. 1998. “TemperatureGradient Effects on Vapor Diffusion inPartially-Saturated Porous Media.”1999 ASME/JSME Thermal EngineeringJoint Conference, accepted.

Webb, S. W., and C. K. Ho. 1997. “Pore-Scale Modeling of Enhanced VaporDiffusion in Porous Media.” Proc. ASMEFluids Engin. Div. 244 (Dallas, TX, 16–21 November): 457–468.

Other

Webb, S. W. 1998. “Gas-Phase Diffusionin Porous Media: Comparison ofModels.” Proc. TOUGH Workshop ’98LBNL-41995 (Berkeley, CA, 4–6 May):269–274.

Webb, S. W., and C. K. Ho. 1998. “Pore-Scale Modeling Using TOUGH2.” Proc.TOUGH Workshop ’98 LBNL-41995(Berkeley, CA, 4–6 May): 288–293.

Webb, S. W., and C. K. Ho. 1998.“Review of Enhanced Vapor Diffusionin Porous Media.” Proc. TOUGHWorkshop ’98 LBNL-41995 (Berkeley,CA, 4–6 May): 257–262.


3508.110

Stress Evaluation and ModelValidation Using LaserUltrasonics

W. Lu, L. W. Peng, J. J. Dike

The evaluation of mechanicalstress has been, and continues to be, anarea of active research due to its effecton the performance and reliability ofmechanical hardware. Of particularinterest to Sandia is the ability to predictand experimentally verify stress fields inengineering components resulting fromboth their intended operation (externalloading) and fabrication process(residual stress). Noncontact stress-measurement techniques are needed forin situ experimental evaluation ofstresses for validation of constitutivemodels and structural analyses to enablemodel–based design.

Based on the acoustoelasticbehavior of material, which refers to thefact that elastic wave velocities varywith stress, stress can be evaluated fromultrasonic-wave velocities. We demon-strated the capability of laser ultrasonic(LU) crystallographic texture measure-ments over a path length of a fewmillimeters, an improvement in spatialresolution of at least an order ofmagnitude over conventional methods.LU is a novel method for the opticalgeneration and detection of ultrasound.These advances will allow us toanalytically and numerically model, aswell as experimentally validate, theacoustoelastic behavior of candidatematerials, thus qualifying this stress-measurement technique.

In the previous year, we demon-strated acoustoelastic techniques instress and stress-gradient evaluationsand the applicability of LU. We alsodeveloped and validated finite-elementmodels (FEMs) for simulating thermaland mechanical responses due toheating by a laser pulse. FEMs areviable tools for guiding LU experimentaltechniques.

This year’s main focus was toapply LU techniques to evaluate stressesin engineering components. We com-pared experimental results and model

predictions. Throughout the investiga-tion we continuously undertook theoreti-cal and experimental study of effects oftexture (preferred orientation ofmaterial) on acoustoelastic behaviors,FEM simulations (or numerical experi-ments) of Rayleigh-wave propagationunder various conditions, and LUexperimental techniques (such asnarrowband wave generation).

This year’s accomplishmentswere in four areas: acoustoelasticity,FEM, LU techniques, and demonstra-tions.

• Acoustoelasticity. We developeda model to include texture effects onacoustoelastic constants of aluminumalloys, which are functions of seventexture coefficients (W400, W420, W440,W600, W620, W640, and W660). We experi-mentally measured acoustoelasticconstants and texture coefficients oftwo AA6061-T6 samples. Model-predicted acoustoelastic constantsfrom texture coefficients are inaccordance with experimental values.This explains why inconsistent valueswere reported in the literature.

• FEM. We validated FEMs bycomparing with analytical results,which we further improved to includetemperature-dependent thermal andmechanical (elastic and plastic)properties of the material. Tempera-ture-dependent properties significantlydecreased the peak magnitudes inwaveform; including plasticity affectedthe shape of the waveform. We usedFEM to simulate several experimentalscenarios. The purpose was to guideexperiments to generate desiredwaveforms, broadband or narrowbandsignal, for stress-gradient evaluation.We investigated the effect of pulsed-laser spot size. It shows that frequencycontent of signal increases as sourcediameter decreases. We simulatednarrowband generation by usingmultiple exciting sources. Increasingthe number of sources with source-spacing fixed narrows the bandwidthof the received waveform. We alsoused FEM for structural analysis forvalidation purposes. We calculated thestress distributions of a compressedring and a welded tube, which we canuse to compare with measured values.

• LU techniques. We demon-strated ultrasonic stress-gradientmeasurement last year by using apiezoelectric transducer for excitationand LU for receiving. To have a fully LUsystem, the critical task was togenerate desired waveforms using alaser. From the guidance of FEM, wesuccessfully developed the techniqueto generate narrowband signals.Unfortunately, there are still a fewproblems to overcome to meet theconsistency and accuracy required forvelocity measurements.

We designed and performedthree experiments to demonstrate theapplicability of LU techniques. First, anannular ring made of AA6061-T6 wascompressed diametrically beyondyield. We measured the residual stressdistribution at the horizontal section,which was in agreement with analyticalpredictions. Second, we made LUmeasurements on a bend beam. Wehad evaluated the residual stress byseveral different techniques such asneutron diffraction, x-ray, etc. LUresults matched other results qualita-tively since the acoustoelastic con-stants of the material were notavailable. The third experiment wasthe welded tube. We made LU measure-ments but were not able to obtainconsistent and accurate velocityversus frequency relations.

• Demonstrations. We developedand demonstrated an LU technique instress measurement and a partial LUmethod in stress-gradient measure-ment. The spatial resolution of thetechnique is about 1 centimeter; thestress and stress-gradient resolutionsare about 40 MPa and 40 MPa/mm,respectively.

Publications

Refereed

Dike, J. J. 1998. “Finite ElementModeling of Ultrasonic Waves Pro-duced by a Pulse Laser.” Rev. ofProgress in Quantitative NondestructiveEval. 17 (San Diego, CA, 27 July–1August): 667–674.

Dike, J. J., and T. M. Sanderson. 1998.“Simulations of Surface Waves Gener-


ated Using Laser Ultrasonics.” Paperpresented to the 25th Annual Review ofProgress in Quantitative Nondestruc-tive Evaluation, Snowbird, UT, 14–19July.

Dike, J. J., and T. M. Sanderson. 1998.“Simulations of Surface Waves Gener-ated Using Laser Ultrasonics.” Rev. ofProgress in Quantitative NondestructiveEval. (New York), submitted.

Lu, W., L. W. Peng, and P. Holland. 1998.“Measurement of Acoustoelastic Effectof Rayleigh Waves Using Laser Ultra-sonics.” Rev. of Progress in QuantitativeNondestructive Eval. 17 (San Diego, CA,27 July–1 August): 1643–1648.

Man, C. S., W. Lu, and J. Li. 1998.“Effects of Crystallographic Texture onthe Acoustoelastic Coefficients forRayleigh Waves in Aluminum.” Paperpresented to the 25th Annual Review ofProgress in Quantitative Nondestruc-tive Evaluation, Snowbird, UT, 14–19July.

Man, C. S., W. Lu, and J. Li. 1998.“Effects of Crystallographic Texture onthe Acoustoelastic Coefficients forRayleigh Waves in Aluminum.” Rev. ofProgress in Quantitative NondestructiveEval. (New York), submitted.

3508.040

Using Higher-OrderGradients to ModelingLocalization Phenomena

D. J. Bammann, D. A. Mosher, N. R.Moody, D. A. Hughes

Prediction of structural failure incomponents due to void growth andductile crack propagation requires aconstitutive model based on the physicsof these processes. As a result, muchresearch is currently directed towardbridging the micro- to macroscales inmechanics of materials to bring betterdescriptions of material response intoour finite-element (FE) calculations. Inmany cases, an attempt to includemicromechanical phenomena into amacroscale model results in meshdependency when implemented into anFE code. Sandia demonstrated this, in

particular, for problems such as damageor crack propagation and strain localiza-tion. Attempts to describe this by localcontinuum damage models leads to theunacceptable condition that anyrefinement of the FE mesh results in achange in the result. This mesh depen-dency results from the lack of a lengthscale in the formulation of the localcontinuum theory. Currently, Sandia’smost accurate FE model (FEM) constitu-tive models use a state-variableapproach but still do not contain alength scale. In this project we aretaking the next step in extending thesemodels by embedding a length scale intothe continuum by introducing higher-order spatial gradients into the evolutionof the state variables. Utilizing this inthe evolution of the dislocation density,both void coalescence and ductilefailure can be accurately modeled whileeliminating the mesh dependency of thesolution. This will also allow a moreaccurate description of shear bands,including the stress and strain level, andan understanding of when shear bandslead to failure and when they areacceptable for a particular design. Weplan an experimental program to helpguide the appropriate choice of a lengthscale as well as provide insight intoappropriate boundary conditions (BCs).Another important part of this projectwill be an attempt to develop a bettermodel of friction by accurately describ-ing the steep gradients in hardness thatoccur near the surface at interfaces.

We modified BCs, motivated bysolutions of image forces on disloca-tions at free surfaces. This wasnecessary to describe the experimen-tal observation that the stress dependson the diameter in torsion of very thinwires. We developed and conducted anexperimental program to isolate aphysical length scale. This involvedthe tensile testing of a series of self-similar thin foils containing an array ofholes. The smallest-hole diameterswere on the order of 8.5 mm. While thetests provided useful information onthe structure of the localized zone, wediscovered that the dependence of themechanical response on changingdimensions would have been better

modeled using foils consisting of singlecrystals. We developed and imple-mented a gradient theory for disloca-tions in a single crystal and used it tomodel cyclic response. The modelpredicts the formation of persistentslip bands in larger-grained materials,consistent with existing experimentalobservations. We performed calcula-tions to model dislocation substruc-tures resulting from frictional loadingof steel plates sliding on copper. Localmodels underpredict both the depth ofdeformation into the material and theincreased hardness of the deformedcopper near the surface. The gradientmodel captured both of these effectswith reasonable accuracy.

Publications

Other

Bammann, D. J. 1998. “A GradientModel of Dislocation–Based Plasticity.”Invited seminar, CalTech, Pasadena,CA, January.

Bammann, D. J. 1998. “A GradientModel of Dislocation–Based Plasticity.”Invited seminar, University of Illinois,Department of Theoretical and AppliedMechanics, Urbana-Champaigne, IL,January.

Bammann, D. J. 1998. “A GradientModel of Plasticity.” Paper presentedto the U.S. National Congress ofApplied Mechanics, Gainesville, FL,June.

Bammann, D. J., and P. R. Dawson.1997. “Effects of Gradients in Harden-ing on Strain Localization.” Plasticity’97, Finite Plastic and ViscoplasticDeformation 1 (Juneau, AK, July): 123.

Bammann, D. J., and P. R. Dawson.1997. “Nonlocal Aspects of Localiza-tion and Failure.” Proc. IUTAM Symp. onPlasticity and Microplasticity 1(Bochum, Germany, August): 125.

Dawson, P. R., D. J Bammann, and D. R.Mosher. 1997. “Modeling the Influenceof Gradients on the Evolution ofDamage in Metals.” Proc. 3rd Internat.Conf. Mater. Processing Defects 1 (Paris,France, July): 223.


3508.120

Altered SimulationProperties for TetrahedralFinite Elements for Use inEngineering Simulation

S. W. Key, K. H. Brown, C. R. Dohrmann,M. W. Heinstein, C. M. Stone

In 3-D numerical simulations insolid mechanics, the current finiteelement (FE) of choice for spatialdiscretization is some form of eight-nodebrick hexahedron. In spite of a multiyearquest, an automatic all-hexahedronmesh-generation scheme for generalgeometries has not been forthcoming.The alternative is tetrahedral FEs, forwhich a number of automatic meshgenerators exist. However, four-nodetetrahedral FEs, while attractive for theircomputational simplicity, result innumerical predictions of abysmalquality. Sandia will develop a tetrahe-dral element with numerical propertiescompetitive with the eight-node brickhexahedron FEs extant today. If theeffort is successful, existing automatictetrahedral mesh generators can beused, and the time- and manpower-intensive efforts currently used to buildall-hexahedral meshes by hand can beavoided.

Theoretical developments led tothe generation of discrete gradient anddivergence operators. We applied anumber of standard numerical teststhat generated very positive out-comes. It is clear that the conceptsemployed were fruitful.

We pursued two separatestudies: (1) We studied a number ofalternative tetrahedral FE (the FE

method is a technique for spatialdiscretization for field equations, inthis case solids) formulations (spectralenrichments and differentnodalizations) to ensure that our finaltetrahedral FE selection could beexpected to meet or exceed oursimulation–based design requirementsfor a new FE for 3-D solids. (2) Detailedstudies of the numerical requirementsfor interactions between indepen-dently meshed 3-D solids via contactalgorithms led to new understandingsof how the new tetrahedral FE will fitinto existing simulation software. Bothof these studies successfully producedlarger understandings of the issues.

Publications

Refereed

Dohrmann, C. R., and S. W. Key. 1998.“A Transition Element for UniformStrain Hexahedral and TetrahedralFinite Elements.” Internat. J. Numer.Meth. in Engineering, accepted.

Dohrmann, C. R., and S. W. Key. 1998.“Enhanced Uniform Strain Triangularand Tetrahedral Finite Elements.”Internat. J. Numer. Meth. in Engin.,submitted.

Dohrmann, C. R., S. W. Key, and M. W.Heinstein. 1998. “A Method for Con-necting Dissimilar Finite ElementMeshes in Two Dimensions.” Internat.J. Numer. Meth. in Engin., submitted.

Dohrmann, C. R., S. W. Key, M. W.Heinstein, and J. Jung. 1998. “A LeastSquares Approach for Uniform StrainTriangular and Tetrahedral FiniteElements.” Internat. J. Numer. Meth. inEngin. 42: 1181–1197.

3508.130

Development,Implementation, andExperimental Validation ofthe Lattice BoltzmannMethod for Modeling Three-Dimensional Complex Flows

J. T. Fredrich, D. R. Noble, R. M.O’Connor, C. E. Hickox, Jr., H. W.Stockman

This project (1) developed codesbased on the Lattice Boltzmann (LB)method for modeling nonreactive andreactive transport in complex geom-etries, including implementing scalable,distributed algorithms, (2) developedmethods and computational algorithmsto extract quantitative statisticaldescriptions of the microgeometry ofporous media, and (3) validated thenumerical codes by comparison withboth laboratory transport and flowexperiments, as well as calculationsbased on other numerical methods. TheLB method shows exceptional promisefor modeling both phenomena atintermediate scales where neithercontinuum models nor moleculardynamics (MD) methods are practical,and also for modeling very large-scalecontinuum flows where conventionalcomputational fluid dynamics (CFD)methods suffer severe difficulties. Thisproject coupled innovative experimentalapproaches, physical and chemicaltheory, novel algorithms, and advancedcomputing techniques and capabilities,and developed an advanced computa-tional framework in which to investigatethe fundamental phenomena character-izing micro- and macroscale complexflows.

Work in the second year focusedon two areas: (1) development of anadvanced capability to model geo-


metrically complex 3-D flows using theLB method, and (2) experimentalvalidation.

Under the first task area we (a)developed single- and multiple-component 3-D LB codes, (b) opti-mized a distributed single-component3-D LB code including parallel I/O andvisualization, (c) developed LB code toenable simulation of other complexflow phenomena such as heat conduc-tion, melting, and moving boundaryproblems, (d) developed code specificto the solution of initial value prob-lems, (e) investigated variable gridresolution, and (f) developed adistributed computational platformbased on Pentium Pro and Pentium IIprocessors and a high-bandwidthswitch for efficient message passing,for use both in code prototyping forthe Accelerated Strategic ComputingInitiative (ASCI) supercomputer and inproduction-scale runs.

Accomplishments under thesecond task area included (a) experi-mental characterization of the 3-Dmicrogeometry and transport proper-ties of complex porous media, (b) codedevelopment for image processing andbinarization of volumetric confocalimage data, and (c) quantitativecomparison of numerical LB simula-tions with laboratory experiments andanalytic test problems.

Publications

Refereed

Fredrich, J. T. 1998. “3-D Imaging ofPorous Media and Application toMicroscale Flow Modeling.” Phys. andChem. of the Earth, submitted.

Lindquist, W. B., and A. Venkatarangan.1998. “Investigating Three-DimensionalGeometry of Porous Media from High-Resolution Images.” Physics and Chem.of the Earth, submitted.

Noble, D. R. 1998. “A Lattice BoltzmannMethod for Partially Saturated Compu-tational Cells.” Internat. J. Modern Phys.C, submitted.

Oh, W., and W. B. Lindquist. 1998.“Image Thresholding by IndicatorKrigging.” IEEE Trans. Patt. Anal. andMach. Intel., submitted.

Stockman, H. W. 1998. “Accuracy andComputational Efficiency in 3-DDispersion via Lattice Boltzmann:Models for Double-Diffusive Fingeringand Dispersion in Rough Fractures.”Internat. J. Modern Phys. C, submitted.

Stockman, H. W. 1998. “PracticalApplication of Lattice-Gas and LatticeBoltzmann Methods to DispersionProblems.” Internat. J. Complex Sys.,submitted.

Other

Fredrich, J. T. 1998. “3-D Imaging ofPorous Media and Application toMicroscale Modeling of Transport.”Annales Geophysicae, Proc. XXIIIGeneral Assembly of the EuropeanGeophysical Society 16 (Nice, France,19–24 April): C254.

Fredrich, J. T. 1997. “3-D Imaging ofPorous Media and Application toMicroscale Modeling of TransportProperties.” Paper presented to LosAlamos National Laboratory, LosAlamos, NM, 18 September.

Fredrich, J. T. 1998. “Microgeometryand Fluid Flow in Porous Media.”Lecture at the GeoForschungsZentrum(Invited), Berlin, Germany, 30 April.

Fredrich, J. T. 1998. “Microgeometryand Fluid-Flow Processes in PorousMedia.” Lecture at SUNY Stony Brook(Invited), Stony Brook, NY, 19 Febru-ary.

Fredrich, J. T. 1998. “Microgeometry ofPorous Media and Fluid Flow.” Lectureat University of Edinburgh (Invited),Edinburgh, Scotland, 3 July.

Fredrich, J. T. 1998. “Microscale FlowModeling in Reconstructed PorousMedia.” Lecture to be given at NewMexico Tech (Invited), Socorro, NM, 4February 1999.

Fredrich, J. T., and R. M. O’Connor.1998. “Microscale Flow Modeling inReconstructed Porous Media.” EOSTrans. Amer. Geophys. Union (SanFrancisco, CA, 6–10 December).

Holdych, D., and D. R. Noble. 1998.“Lattice Boltzmann Model for Second-Order-Accurate Simulation of InitialValue Problems.” Paper presented tothe 1998 APS Meeting, Philadelphia, PA,November.

Lindquist, W. B. 1998. “InvestigatingThree-Dimensional Geometry ofPorous Media from High-ResolutionImages.” Annales Geophysicae, Proc.XXIII General Assembly of the EuropeanGeophysical Society 16 (Nice, France,19–24 April): C255.

Noble, D. R. 1998. “Mixed ConvectionOver a Backward-Facing Step in aVertical Channel by the LatticeBoltzmann Method.” Proc. ASME HTD,ASME/AIAA Thermophys. Conf. 357-2(Albuquerque, NM, June): 167.

O’Connor, R. M., and J. T. Fredrich.1997. “ARANEAE—A Scalable Systemfor Distributed Computing.” Paperpresented to the Scalable ClusterWorkshop, Monterey, CA, 21–22November.

O’Connor, R. M., J. T. Fredrich, and H.W. Stockman. 1998. “Microscale FlowModeling in Geologic Materials.”Annales Geophysicae, XXIII GeneralAssembly of the European GeophysicalSociety 16 (Nice, France, 19–24 April):C255.


3508.140

Capturing Recrystallizationof Metals with a MultiscaleMaterial Model

D. A. Hughes, M. A. Miodownik, A. W.Godfrey, E. A. Holm, S. M. Foiles, D. J.Bammann

The goal of this project is todevelop a predictive continuum modelthat incorporates essential mechanismsfrom the atomic, dislocation substruc-ture, and grain-size length scales. Sandiawill accomplish this by developing anonlinear nonequilibrium thermody-namic gradient theory that provides themathematical framework to incorporatekey microstructural processes. We willpredict the physics at each length scalefrom experimental discovery andtheoretical calculations, and the bridgesbetween each length scale and thecontinuum level will be established bytheir contribution to the thermodynamicprocess. Although the framework we aredeveloping is often more general, wechose to apply this formulation to theprediction of recrystallization processesin metals. Recrystallization (or anneal-ing) occurs when cold-worked metalsare heated. Above approximately 60% ofthe melt temperature, new strain-freegrains nucleate and grow to consume allthe cold-worked metal. This drasticallychanges the dislocation density, grainsize, hardness, and ductility of thematerial. Recrystallization often occursduring manufacturing, during high-ratedeformation, and in high-temperatureenvironments. The continuum-levelmaterial model will evolve macroscalematerial response based on models atlower-length scales incorporatingdislocation structure evolution, grainnucleation, and grain changes due torecrystallization. Specifically, a mesos-cale recrystallization model based on aMonte Carlo Potts model will embody

the local dislocation structure, grainorientation, and strain energy, which wewill correlate with the variables in thecontinuum model. Automated micro-structural analyses in the transmissionelectron microscope (TEM) supple-mented by atomic-scale simulations willprovide experimental discovery ofdislocation structure evolution andnucleation in selected bicrystals.Quantitative statistical data of disloca-tion and boundary properties combinedwith results of atomic-scale simulationsand scaling theory will provide relevantparameters for models at the mesoscale.These parameters will enter new kineticequations for dislocation structureevolution and a multicrystal model oflocal orientation evolution.

Accomplishments at the con-tinuum-level material constitutive lawinclude the following:

(1) At the macroscale, in collabo-ration with Georgia Tech, we added anadditional state variable to the rate-and temperature-dependent BCJ(Bammann Chiesa Johnson) plasticitymodel (nongradient version) tocrudely describe dynamic recrystalli-zation. The evolution of the variabledepends on a critical function of theexisting state variables, strain rate,and temperature. The model comparesreasonably well with data on coppercompression specimens.

(2) We incorporated the kinemat-ics of finite deformation plasticity intothe thermodynamic approach ofGurtin and Fried. We extended thisformulation to endow the continuumwith an extra rotational degree offreedom by decomposing the deforma-tion gradient into elastic, plastic, androtational parts. We used this sameapproach of Gurtin and Fried todevelop a phase-field theory for use inmodeling grain growth and recrystalli-zation from a continuum perspective.

At the mesoscale we incorpo-rated 3-D dislocation substructures

determined by experiment and MonteCarlo modeling into the mesoscalerecrystallization model. The mesoscalemodeling effort focused on determin-ing how strain-free nuclei form fromthe subgrain network. To convert the2-D to a 3-D subgrain structure, wedeveloped a new Monte Carlo algo-rithm that adjusts subgrain orienta-tions to reflect the experimentallyobserved scaling laws formisorientation angles. Using thismethod, we generated realisticmicrostructures in 3-D that match allgeometric and orientational param-eters determined from experiments.We implemented the Read-Shockleymodel for grain boundary energy as afunction of misorientation in thesubgrain model. We performed thefirst 3-D simulations of grain growthwith anisotropic grain boundaryenergy, and they showed behaviorconsistent with the thermodynamicanalyses.

At the atomistic to grain scale,the deformation characteristics andresulting dislocation structure of thedeformed bicrystal are important tothe nucleation study. We grew,deformed, and characterizedbicrystals with Laue x-ray diffractionand TEM. We observed and measuredthe dislocation structure of acompressed [421] bicrystal in theTEM. This characterization revealed avery heterogeneous microstructurewith large rotations. These hetero-geneities are important in characteriz-ing potential nucleation sites.

Experimental observations ofuniversal scaling for deformationmicrostructure evolution provideconstraints on the continuum mechan-ics finite-element (FE) treatments. Tobe consistent with the observedscaling, we reduced the scalingproperties to three constrainingequations. We will incorporate theseconstraining equations into FE models.


Publications

Refereed

Campbell, G. H., S. F. Foiles, H. Huang,D. A. Hughes, W. E. King, D. H. Lassila,D. J. Nikkel, T. D. de la Rubia, J. Y. Shu,and V. P. Smyshlyaer. 1998. “MultiscaleModeling of Polycrystal Plasticity: AWorkshop Report.” Mater. Sci. Eng. A,accepted.

Grach, G., M. T. Lusk, and D. J.Bammann. 1998. “A Modulated EnergyFunction for Modeling Dislocation–Based Plasticity: Part 1 Production.”Internat. J. Plasticity, submitted.

Gurtin, M. E., and M. T. Lusk. 1997.“Sharp-Interface and Phase-FieldTheories of Recrystallization in thePlane.” Physica D, submitted.

Hughes, D. A., D. C. Chrzan, Q. Liu, andN. Hansen. 1998. “Scaling ofMisorientation Angle Distributions.”Phys. Rev. Lett., accepted.

Lusk, M. T. 1998. “A Phase-FieldParadigm for Recrystallization andGrain Growth.” Proc. Royal Society ofLondon A, accepted.

Lusk, M. T. 1998. “On a ModulatedEnergy Function for Simulating GrainGrowth and Recrystallization.” Phys.Rev. B, submitted.

Other

Battaile, C. C., and E. A. Holm. 1998.“Evolution of 2-D Potts Model GrainMicrostructures for an Initial HillertSize Distribution.” Proc. Internat. Conf.on Grain Growth, submitted.

Chrzan, D. C. 1997. “Toward a Disloca-tion–Based Theory of Cell Formation.”

Paper presented to the 4th U.S. Con-gress on Computational Mechanics,San Francisco, CA, 6–8 August.

Godfrey, A., and D. A. Hughes. 1998.“Characterization of Dislocation WallSpacing Distributions.” Solidification1998, in press, ed. S. P., Marsh, et al.

Hansen, N., and D. A. Hughes. 1998.“Structural Parameters and Strength.”Paper presented to the Joint ASME,ASCE, SES Summer Meeting, Evanston,IL, 29 June–2 July.

Holm, E. A. 1997. “Applications ofMesoscale Materials Models atSandia.” Paper presented to theCaterpillar Research Group Seminar,Peoria, IL, September.

Holm, E. A. 1998. “Modeling of Micro-structure-Property Relationships.”Paper presented to the GordonResearch Conference in PhysicalMetallurgy, Plymouth, NH, June.

Holm, E. A., C. C. Battaile, M. D.Rintoul, and H. E. Fang. 1998. “Applica-tions of Grain Growth Modeling.”Paper presented to the 3rd Interna-tional Conference on Grain Growth,Pittsburgh, PA, June.

Hughes, D. A. 1997. “Scaling of Defor-mation Microstructures.” Presentationto Northwestern University, Evanston,IL, June.

Hughes, D. A. 1998. “Scaling of Disloca-tion Structure Evolution.” Paperpresented to the NIST Workshop onWork Hardening and DislocationPatterning in Metals, Pleasanton, CA,June.

Hughes, D. A. 1997. “The Effect ofDislocation Microstructures and Grain

Subdivision on Crystal Plasticity.”Paper presented to the Finite Plasticand Viscoplastic Deformation, 6th

International Conference on Plasticityand Its Current Application, Juneau,AK, July.

Lusk, M. T. 1998. “A Modulated EnergyFunction for Grain Growth of Recrys-tallization.” Paper presented to theColorado School of the Mines, Golden,CO, January.

Lusk, M. T. 1997. “A New Phase-FieldModel for Grain Growth and Recrystal-lization.” Paper presented to the 2nd

Euroconference and InternationalSymposium on Material in Deformationand Fracture, Thessaloniki, Greece,September.

Lusk, M. T. 1997. “A Phase-FieldParadigm for Grain Growth andRecrystallization.” Presentation to theUniversity of Colorado, Golden, CO,November.

Lusk, M. T. 1998. “Modulated EnergyFunctions and Recrystallization.”Paper presented to the MaterialsResearch Society, Symposium L:Interaction of Phase and DefectMicrostructures in Metallic Alloys,Boston, MA, 2–6 December.

Lusk, M. T. 1998. “On Phase-FieldParadigms for Grain Growth andRecrystallization.” Paper presented tothe California Institute of Technology,Pasadena, CA, May.

Rollett, D., W. W. Mullins, M. D. Rintoul,and E. A. Holm. 1998. “The LinkBetween Kinetics and ConfigurationalStatistics in Two-Dimensional GrainGrowth: Comparison of Theory andSimulation.” Proc. Internat. Conf. onGrain Growth, submitted.


3508.150

Nondeterministic Modeling inEngineering Science

J. R. Red-Horse, D. G. Robinson, L. P.Swiler, V. J. Romero, T. L. Paez

Physical processes that are thesubject of engineering analyses invari-ably contain parametric entities thatcan, at most, be specified to within somelevel of uncertainty. The ability toevaluate the nature of the predictedsystem response in the face of thisinevitability is a vital risk-reducingcapability made necessary by the newmodel–based weapons-design initiative.The subject approach is to use approxi-mate analytical methods to estimateresponse uncertainty using probabilisticmeasures. These approximationschemes will require only that pointanalysis results be available throughwhich analytically complete probabilis-tic descriptions will result. Thus, not onlycan the methodologies be easilywrapped around existing analysis codes,but significant reductions in computa-tional requirements, relative to MonteCarlo methods, also are often realizedwithout a reduction in probabilisticinformation. The objectives of thisresearch effort are to develop a suite ofviable, computationally feasible,analytical approaches that can charac-terize (1) certain classes of inputuncertainty, (2) the propagation ofstatistical uncertainty through analyticalmodels to response quantities ofinterest, and (3) the proportion thatparticular physical model primitivescontribute to that propagation process;that is, we will develop a means forperforming probabilistic sensitivityanalyses. The goal is to provide Sandiawith new methodologies and computa-tional tools for assessing the results ofpredictions in the face of approximationand uncertainty that are inherent to theprocesses being modeled.

This fiscal year, efforts included(1) establishing a technique, based ona method known as bootstrap sampling,for assessing the accuracy of probabil-ity approximations made with theAdvanced Mean Value (AMV/AMV+)techniques over a broad range ofapplications, (2) examining theaccuracy of AMV/AMV+ techniques asa function of properties of theresponse surfaces themselves, (3)developing a simplified version of thestochastic finite-element method(FEM), specific to linear analyticalmodels, and running it externallyaround a local, general, FE code on astructural mechanics application, (4)investigating three alternative transfor-mation methods that possess thepotential to overcome weaknesses inAMV: a coordinate change usingstereographic mapping, the likelihoodmethod, and the maximum likelihood,(5) completing the development of thefinite-element/lattice-sampling (FE/LS)progressive response surface con-struction algorithm and subsequentlytesting it on nondeterministic andoptimization sample test problems,and (6) developing a methodology forbuilding univariate probabilisticmodels of input parameters usingmeasurement data as the basis.

Publications

Other

Red-Horse, J. R., and T. L. Paez. 1998.“Assessment of Probability ModelsUsing the Bootstrap Method.” Proc. 39th

Structures, Structural Dynamics, andMater. Conf. 1 (Long Beach, CA, 20–23April): 1001–1008.

Red-Horse, J. R., and T. L. Paez. 1998.“Uncertainty Evaluation in DynamicSystem Response.” Proc. 16th Internat.Modal Anal. Conf. 4 (Santa Barbara, CA,February): 1206–1212.

3508.160

Lagrangian Modeling ofRadiative Transport

L. A. Gritzo, P. E. Desjardin, J. H.Strickland

Many complex multiphysics,multiscaled, time-dependent processesinclude radiative heat transfer inturbulent flow. Conventional grid–basedmodels are not well suited for suchproblems due to the complexity ofgridding domains, which are very largerelative to the scale required to resolvethe important transport phenomena. Alogical alternative is the gridless,Lagrangian–based approach employedin vortex methods that have been usedsuccessfully to simulate turbulencedynamics in internal and external flows,mixing flows, and buoyant jets andplumes. The same strategy wasemployed at M.I.T. to formulate thetransport element method, which is usedwith the vortex method, to solve thespecies transport equation and theenergy equation in nonreacting andreacting flows. The development of acompatible approach to simulateradiative transport, which exploits fastsolvers developed at Sandia, is theobjective of this effort. We are usingmassively parallel (MP) architectures toenhance computational tractability.

We developed a gridless tech-nique (compatible with numericalsimulation of the flow and temperaturefield by gridless vortex and transportelement methods, respectively) for thesolution of the integral form of theradiative transfer equation for anemitting and absorbing medium withuniform properties. We obtained thesolution by representing the mediumby Lagrangian elements whosestrength depends on the absolutevalue and/or gradients of localtemperature. We compared results toestablished and newly developedclosed-form solutions for a planarmedia. We illustrated significant errorsin other techniques that includesimplifications of the governingequations by direct comparison withthe present solutions. We also devel-


oped a fast-solver algorithm, based onthe expansion of the Green’s functionin terms of a convergent separableseries, for radiative transfer in a planarmedia. We investigated axisymmetricforms of the radiative transfer equa-tion and showed them not to beconducive to the favorable form ofequations obtained in planar or 3-Dmedia. We developed an accurate,approximate solution strategy thatincludes near- and far-field formula-tions and are presently coupling it tothe transport element method code toprovide combined solutions ofreacting flow and radiative transport.We are also updating the coupledaxisymmetric code to include fastsolvers for the fluid-flow field andmessage-passing constructs for MPcomputing. We developed a 3-D directsolver and are verifying the resultsusing closed-form solutions for planarmedia. We developed a 3-D fast solverand are presently exercising andbenchmarking it. Fast solvers for bothplanar and 3-D media show order-of-magnitude decreases in computationalexpense for reasonable amounts ofelements and are amenable to use in aparallelization framework recentlydeveloped at Sandia. We developedand are implementing and testing aformulation for nonuniform radiativeproperties. We also defined conceptualtreatments of solid boundaries.

Publications

Refereed

Gritzo, L. A., and J. A. Strickland. 1998.“A Vortex and Transport ElementMethod Compatible Technique forSolving 1-D and 3-D Radiative HeatTransfer.” Proc. 3rd Internat. Workshopon Vortex Flows and Relat. Numer. Meth.(Toulouse, France, 24–27 August).

Gritzo, L. A., and J. A. Strickland. 1998.“Gridless Solution of the RadiativeTransfer Equation for Fire and Com-bustion Calculations.” CombustionTheory and Modeling, accepted.

Strickland, J. H., R. S. Baty, L. A. Gritzo,and G. F. Homicz. 1998. “Fast MultipoleSolvers for Three-Dimensional Vortex

and Radiation Problems.” Proc. 3rd

Internat. Workshop on Vortex Flows andRel. Numer. Meth. (Toulouse, France,24–27 August).

3508.170

High-Resolution Modeling ofMultiscale TransientPhenomena in TurbulentBoundary Layers

A. R. Kerstein, T. Echekki, S. E. Wunsch,V. Nilsen, T. D. Dreeben, R. C. Schmidt

Modeling of transient multiphysicsphenomena in turbulence is especiallydifficult near walls, where the enhancedrole of molecular transport introduceslength scales far smaller than scalesresolvable by 3-D computational models.Present-day empirical wall treatmentsare not applicable to strongly coupledmultiphysics environments.

One-dimensional turbulence(ODT), the novel modeling approachadopted in this project, addresses thisdifficulty by capturing relevant lengthand time scales in an unsteady 1-Dsimulation. In this research effort,Sandia is coupling the coupled effects oftransient applied shear, buoyancy,exothermic chemical reactions, and heatand mass transfer, with attendantproperty variations, into ODT. We willuse this formulation to perform paramet-ric studies to support the development ofimproved wall treatments for steady-state flow solvers, with emphasis on theneeds of the FUEGO fire-model develop-ment effort.

We formulated an ODT–basedwall submodel for large-eddy simulation(LES). We will implement it first withinan LES code suitable for testing anddirect comparison with existing wallsubmodels. Subsequently, we willimplement it within a code architecturethat is compatible with Sandia softwareintegration objectives. The implementa-tion of this code will demonstrate newcapabilities needed to simulate combus-tion, heat transfer, and relatedmultiphysics phenomena in turbulentflows with wall geometries relevant toprogrammatic applications.

We formulated ODT as a suite ofutility modules within Sandia’sCHEMKIN gas-phase chemistry/transport/thermodynamics codeframework. This formulation callsCHEMKIN subroutines to computemolecular-level subprocesses. Thisinformation is fed back to the ODTdriver to serve as input for the ODTcomputations of thermal expansionand viscous effects on the turbulenceevolution. Within this framework, weimplemented two formulations of ODT:the original boundary-layer formula-tion and an impinging-flow formula-tion. We performed verification tests ofthese formulations.

We also incorporated andverified the code modifications neededto simulate buoyancy-driven flowalong a vertical wall. We performed avalidation study demonstrating thepredictive capabilities of this formula-tion, involving comparisons to labora-tory data and to data from fullyresolved 3-D flow solutions. The ODTsimulations reproduced previouslyobserved flow-structure and heat-transfer parameter dependencies andextrapolated them to larger-scaleflows. These scalings have not yetbeen explained theoretically. ODT iscurrently the only available method forextrapolation from the regime that isaccessible by 3-D simulation to larger-scale flows of programmatic interest.

We developed and are testing aformulation of ODT configured for useas a wall submodel for LES. We basedthis formulation on a novel concept forrepresenting the time evolution of a3-D velocity vector on a linear (1-D)spatial domain. In contrast, ODT asimplemented in the effort to daterepresents the time evolution of asingle velocity component on a linearspatial domain.

We identified an LES formulationsuitable for incorporation of this wallsubmodel. It is based on an LES codebeing used by a Stanford Universitygroup to test a class of wall submodelsthat couple to the LES in the samemanner as required for the ODT wallsubmodel.


3508.180

Dispersive Measurements ofVelocity in HeterogeneousMaterials

L. C. Chhabildas, J. B. Aidun, M. R. Baer,W. M. Trott

To provide real-time data tovalidate 3-D numerical simulations ofheterogeneous materials subjected toimpact loading, Sandia adapted anoptically recording velocity interferom-eter system (ORVIS) to a line-imaginginstrument capable of generating precisemeasurements of spatially resolvedvelocity variations during dynamicdeformation. Combining independentlyvariable target image magnification andinterferometer fringe spacing, thisinstrument can provide spatial resolu-tion of a few millimeters along a linesegment together with a temporalresolution of < 0.2 ns. As a complemen-tary development, we also demonstrateda simultaneous stop-motion imaging ofthe complete fringe field (using a fast-gating intensifier/charge-coupled device[CCD] system). This additional capabil-ity can be used to generate a complete2-D map showing velocity variations ina moving surface at one point in time.These novel diagnostic methods forexamining the mesoscopic-scaledynamic response of heterogeneousmaterials have been packaged for use inwell-controlled, well-characterizedimpact-loading experiments at a gas-gunfacility, and we designed and assembledthe optical interface with the gun targetchamber. Candidate substances forexamination include such programmati-cally interesting materials as pressedgranular explosives, ferroelectricceramics, and ALOX (alumina-filledepoxy). We will use observed spatiallyresolved velocity profiles to evaluatecritically corresponding 3-D computersimulations on the selected materials.Validation of computer predictions at themesoscopic scale is designed to encour-age development of internal statecontinuum models that will also bevalidated at the macroscopic level usingconventional shock-wave profiletechniques. Validation of material

response at these two different materialresponse levels will provide an unprec-edented capability for developing andvalidating physics–based modelsdirected at better predictive modeling asa replacement for extensive experimen-tal testing of weapons systems andsubcomponents.

The principal focus of ourresearch involved evaluation andoptimization of optical designs foradapting line-imaging ORVIS to providereal-time measurements of spatiallyresolved (mesoscopic scale) velocityvariations in impact-loaded heteroge-neous materials. We performed initialtesting of these designs on laser-drivenflyer plates that exhibit fine-scalenonplanarity and Rayleigh-Taylorperturbations, depending on exactlaunch conditions. We then packagedthese designs in a portable configura-tion for use in well-controlled experi-ments on heterogeneous materials at agas-gun facility.

Characterization of target-imaging optics in ORVIS demonstratedthat precise control of image magnifi-cation is achievable over a wide range(x10–x200); fringe spacing is indepen-dently and widely variable as well.Moreover, we determined that imagemagnification can be made to berelatively insensitive to target dis-tance. These features enable the studyof different heterogeneous materialshaving varying characteristic scalelengths (< 10 mm to > 1 mm) andpermit location of the interferometersystem at a safe, variable distancefrom a gas-gun target chamber.

Free-surface velocity measure-ments on laser-accelerated flyers andwave profile measurements of flyersimpacting a lithium-fluoride (LiF)window verified the ability of line-imaging ORVIS to discern fine-scalephenomena at temporal and spatialresolutions of < 0.2 ns and < 10 mm,respectively. We also developed a newcomplementary technique utilizing aredundant set of image/fringe data. Weused a fast-gating, intensifier/CCDsystem to obtain stop-motion imagesof the complete fringe field that can beused to generate detailed maps of thetarget surface velocity.

We assembled a fully functioningline ORVIS setup, including sourcelaser, streak camera, intensifier, andCCD detector, on a 2 x 6 opticalbreadboard, and transported it to agas-gun site at Sandia. In addition, wedesigned, assembled, and tested theoptical interface to the gas-gun targetchamber. We assembled hardware forthe initial set of experiments consist-ing of fused silica targets (bothoptically flat and wedged samples)designed for planar impact by fusedsilica. The experimental designsupports simultaneous line ORVIS andconventional single-point velocityinterferometer system for any reflector(VISAR) measurements. Preparationsfor the initial set of gas-gun experi-ments were nearly complete as thefirst year of the project came to aclose.

Finally, in concert with experi-mental progress, we developed arobust method for individual-linefringe analysis (based on push-pullVISAR concepts) for line-imagingORVIS. In reducing records of numer-ous flyer tests, we showed that thispowerful approach can generateremarkably clean velocity-time profilesfrom noisy image data. We generatedand are currently testing an automatedanalysis routine. This routine includesORVIS image import and pre-process-ing (e.g., image rotation, determinationof fringe separation, backgroundsubtraction, etc.), followed by exportto an existing VISAR analysis platform.

3508.190

A Physically–BasedComputational Method forPredicting GeneralizedFracture

P. A. Klein, E. S. Alber

Fracture is an important mode offailure, and computational methods forits simulation are essential to failureprediction. Yet an efficient, exhaustivecomputational method for accuratefracture prediction does not exist at thistime. Attempts at combining classical


(or continuum) fracture mechanics withthe standard finite-element method(FEM) or with the element-free Galerkin(EFG) method offer a good first step;however, FEM has inherent difficulties inresolving arbitrary crack trajectories,and the current development of EFG islimited to the growth of predefined,existing cracks. Furthermore, bothapproaches are subject to the limitationsof classical fracture mechanics, whichdeals with preexisting cracks and withcrack growth criteria that have not beenconfirmed under generalized conditions.

This project will develop a newcomputational tool based on EFG inconjunction with embedded traction-separation (or cohesion) relations. EFGprovides an automatic resolution of newsurfaces as they develop during thesolution process (this avoids theremeshing and remapping required inFEM), and the traction-separationrelation provides a physically–basedresistance to fracture. This tool iscapable of solving the entire specter offracture, which encompasses cracknucleation, crack growth, crack interac-tion, and crack branching (fragmenta-tion). This provides a high-fidelitycapability for predicting generalizedfracture with application to a wide rangeof problems, including polymer aging,thermally induced cracking ofencapsulants, glass fragmentation, andweapon slap-down.

We developed a new 2-D code(written in FORTRAN-90) based on theEFG method with emphasis on cohe-sive fracture. The code can be used fortransient-dynamic or quasi-staticanalysis and represents a computa-tional method that resolves cracks asthey appear during the solutionprocess, without any changes to theinitial discrete model. We validated thecode by solving several simple testproblems. Currently, we are using it tosimulate intergranular-fracture inceramic materials and interaggregate-fracture in concrete. The code allowsfor crack initiation (i.e., nucleation),crack growth (including branching orkinking), and crack arrest to emerge asa natural outcome of the analysis (i.e.,there is no need for an a priori crite-rion to identify the onset of such

phenomena even in the presence ofwidespread dissipative deformations).We developed and are currentlyvalidating a 3-D version of the code;preliminary results are encouraging.We also plan to combine the currentapproach with the virtual internalbound model to treat crack initiationand growth.

3508.220

Micromechanical FailureAnalyses for Finite-ElementPolymer Modeling

R. S. Chambers, T. R. Guess, D. B. Adolf,E. D. Reedy, Jr., C. S. Lo

Accurate failure models areneeded in analyses to predict margins ofsafety to determine whether encapsu-lated components meet life-cyclerequirements. Using recently developedand validated viscoelastic models forepoxy encapsulants, the stress concen-trations in fracture process zones nearfailure-prone corners and materialinterfaces now can be computedaccurately as functions of time andtemperature. This technology enables usto consider a novel approach fordeveloping a micromechanics–basedcohesive failure criterion that includesnonlinear viscoelastic (NLVE) behavior.

Linear elastic fracture mechanicsadopts a macro approach and ignoresthe details of the material behavior atthe crack tip. Alternatively, Sandia willmodel the details of the stress/strainbehavior within the process zonesurrounding a crack tip to pursuemicroscopic mechanisms. Using aproven NLVE material model for epoxyencapsulants, we will analyze crack-tipdeformation histories in fracturesamples that are loaded to failure. Wethen will look for correlations betweenthe local crack-tip behavior and new aswell as traditional fracture parameters.This approach will scrutinize failurecriteria based on such things as finiteextensibility of the polymer network,shear banding, cavitation, or subcriticalcrack growth. This project also providesa way for studying the dependencies ofmacrofracture parameters on tempera-

ture and aging and may offer a moregeneral approach to predicting failurethat works in situations where tradi-tional fracture mechanics does not.

A key aspect of this project wasto design and manufacture testsamples and perform fracture experi-ments to collect data for use both inmodel validation and in defining anNLVE material–based cohesive failurecriterion. We selected a three-pointbending test on a pre-cracked beam toexperimentally measure fracturetoughness (KIc). We made samples andconducted tests at three differenttemperatures (–60°, 23°, and 50°C) andthree different loading rates (.01, .1,and 1 mm/s). Similar test data col-lected on partially cured samplesshowed that toughness is much moresensitive to the degree of cure. We alsodesigned and fabricated a second testgeometry representative of crackingaround an encapsulated sharp-cornered inclusion. We performed anovel fracture analysis of an encapsu-lated inclusion test sample extendingtraditional linear elastic fracturemechanics to discontinuities otherthan cracks. This macro approachseeks to relate failure to the stressintensity factor characterizing theinclusion corner. Cracks observedduring thermal cooling on differentshaped inclusions with differentinterface adhesion have thus far beenconsistent with expectations.

We added the NLVE constitutiveequation to the JAS3D finite-elementcode and validated it in tension,compression, and torsion over a 50°temperature range by analyzing testsand comparing predictions to mea-surements. The higher-temperaturetests showed that better relaxationspectra definitions are needed tocapture the post-yield softening. Weshowed the formalism, strain measure,and clock mechanism to be qualita-tively correct. We are now resolvingparameter sensitivities. To beginaddressing modeling issues, wemeshed the cracked, three-pointbending sample and analyzed itelastically and viscoelastically. Weidentified two refinement schemes toresolve crack-tip stresses.


3508.210

Development of In SituDiagnostics forSimultaneous Measurementof Transient Gas Species andSoot in Large Fires

C. R. Shaddix, P. D. Ludowise, L. R.Thorne, J. R. Ross, H. A. Johnsen, D. K.Ottesen, S. W. Allendorf, L. A. Gritzo

The thermal hazard posed by afire to a weapon or other engineeredsystem is a consequence of combinedradiation and convection from high-temperature soot and gases. Thedevelopment of advanced, predictivemodels of this hazard requires detailedknowledge of the transient chemicalstructure and soot distributions withinreal-scale fires. At present, there are nomeasurements, and hence no under-standing, of transient gaseous speciesgeneration and transport in large, fullyturbulent fires.

In this project Sandia is applyingtunable diode laser absorption spectros-copy (TDLAS) to perform in situ,temporally and spatially resolvedmeasurements of gas species and soot indiscovery and validation experiments inreal-scale fires. We identified chemicalspecies that are most likely to bedetected and that are characteristic ofthe hydrocarbon fuel, combustionintermediates, and combustion products.We are combining TDL measurements ofthese species with absorption/emissionmeasurements of soot concentration andtemperature. In addition, we areexploring the possibility of detectingacetylene because of its importance insoot formation.

Success of this project depends onthe ability to develop and apply TDLASin a hot, transiently attenuating environ-ment, with several TDL lasers (to accessseveral gas species). We constructed abuoyant flame facility to evaluatemultipass techniques for improving the

system sensitivity and other probedesign issues. In addition, we conductedevaluations of several different possibleapproaches for laser multiplexing. Weare performing experiments in a low-pressure, flat-flame, Fourier transforminfrared (FTIR) facility to identify andquantify the strongest absorption linesfor the target species.

We completed backgroundresearch and design work that arecritical to the successful implementa-tion of the TDL gas species measure-ment technique in fires during the firstyear of this project. These efforts maybe grouped according to the followingconsiderations: assessment of the bestdetectable gas species to measure infires and the optimal spectral locationsfor their measurement, development ofa suitable laser multiplexing approach,and design of a sensitive, fast TDLdata-acquisition system.

Analysis of spectral consider-ations, expected species concentra-tions, and predicted absorption linestrengths at high temperaturesresulted in tentative identification ofmethane, carbon monoxide, carbondioxide, and water as good candidatesfor detection in fires. We extensivelyanalyzed and compared the HiTran96and HiTemp spectral databases withrecent measurements reported in theliterature to identify the most promis-ing spectral regions for high-tempera-ture transitions of target moleculesand to provide estimates of theabsorption line strengths at hightemperatures. In addition, we identi-fied and acquired detailed chemicalkinetic mechanisms for aviation fueland similar transport fuels. We areperforming calculations of theexpected chemical compositions fordifferent stoichiometries and residencetimes. Work is continuing in evaluatingacetylene and ethylene as potentialtarget species and in identifyinginterfering carbon dioxide and waterabsorption features, using a low-pressure, flat-flame, high-resolution

FTIR facility. The potential detection ofoxygen together with the other speciesdoes not appear promising due to theneed to use separate fiber optics anddetector for the short wavelength (760nm) of these transitions.

We evaluated several approachesto combining (or multiplexing) severalTDLs that have been suggested in theliterature for their applicability withinthe constraints of this project. The useof either injection-current staggeringor high-frequency multiplexing, orperhaps even a hybrid approachcombining these two concepts,appears to be the most promisingpossibility. We initiated experiments ina buoyant flame facility with variablesoot concentrations to evaluate thefeasibility of these concepts.

To achieve the rapid response(> 100 Hz) and short measurementlength (2–5 cm) desired for grid-levelfire measurements, improvementsmust be made in the sensitivity of theTDL system. We performed experi-ments assessing the noise characteris-tics of fiber–based TDL systems, andan analysis of existing soot data from apool fire suggests that an optimal pathlength for species measurements inthis environment is 20–30 cm. Conse-quently, we are designing a parallel-mirror, off-axis multipass samplingsystem for the fire probe. Also, wespecified and acquired a fast A/D(analog-to-digital) converter andcomputer system for TDL dataacquisition.

Publications

Other

Shaddix, C. R., S. W. Allendorf, D. K.Ottesen, H. Johnsen, and K. Hencken.1997. “Species Measurements withNear-IR Tunable Diode Lasers inDemanding Environments (includingFires).” Presentation to the NationalInstitute of Standards, Building andFire Research Laboratory (Invited),Gaithersburg, MD, 15 December.


3508.240

A Phenomenological Modelfor MulticomponentTransport withElectrochemical Reactions inConcentrated Solutions

K. S. Chen, M. E. Coltrin, F. M. Rupley, R.S. Larson, G. H. Evans

Liquid-phase electrochemicalprocesses play important roles inSandia’s missions (e.g., thermalbatteries, stockpile metal corrosion, fuelcells, and electroless and electrolyticplating as in LIGA [German for lithogra-phy, electroforming, molding] fabrica-tion of microelectromechanical systems[MEMS] devices); the processes caninvolve multicomponent transport ofcharged species with simultaneouselectrochemical reactions in concen-trated solutions. For example, in athermal battery cell, an interactingmolten mixture of electrolytes istransported between electrode surfaceswhere reactions take place; consump-tion of the electrode results in movingboundaries. Accurate prediction ofbattery performance (e.g., dischargevoltage) requires proper description ofdiffusion of charged species (driven byconcentration and electrical-potentialgradients), convection due to volumechanges, energy transport, electrochemi-cal reactions, and thermodynamicpotentials. Classical dilute-solutionframework based on Fick’s first law isgenerally valid only for non-interactingspecies diffusing in dilute solutions. Inshort, a predictive capability is lacking

at Sandia for modeling electrochemicalprocesses such as thermal batteries.

Sandia will develop a phenomeno-logical model for multicomponenttransport of charged species withsimultaneous electrochemical reactionsin concentrated solutions using a state-of-the-art framework, accounting forinteractions between multiple diffusingspecies. The new framework will utilizethe Stefan-Maxwell equations, whichdescribe multicomponent diffusion ofinteracting species using composition-insensitive binary diffusion coefficients.We will validate the phenomenologicalmodel, based on conservation of mass,momentum, energy, and species, as wellas the law of mass action, using dataavailable at Sandia for thermal batter-ies. We also will develop a liquid-phaseelectrochemistry package and a liquid-phase transport package for computingreaction rates and thermodynamic andtransport properties. The coupling of theGOMA–based computer model with theliquid-phase electrochemistry and liquid-phase transport packages will provideSandia a unique predictive capability formodeling electrochemical processessuch as thermal batteries.

We completed conceptualdesigns of the liquid-phase electro-chemistry and liquid-phase transportpackages and theoretical develop-ments for the two packages. Inaddition, we modified the existingSurface CHEMKIN Interpreter and rateroutine to allow for the specification ofButler-Volmer kinetics. We developed ageneral theoretical framework fordescribing multicomponent transportof ionic (i.e., charged) species with

simultaneous electrochemical reac-tions in concentrated solutions. Weformulated equations that govern thephenomena of species diffusion andconvection, electrochemical reactions,energy transport, and electrode-poreevolution in a Li(Si)/FeS2 thermal-battery cell. We made sample predic-tions using a 1-D computer modelbased on that developed at UC–Berkeley. We made substantialprogress toward developing a multidi-mensional GOMA–based computercode for modeling multicomponenttransport of charged species withsimultaneous electrochemical reac-tions in concentrated solutions as inthermal batteries. (GOMA is a multidi-mensional, multiphysics, finite-elementcode being developed at Sandia.)Specifically, we implemented in GOMAthe Stefan-Maxwell flux model fordescribing transport of multiplespecies (neutral or charged). Wemodified the existing GOMA frame-work to allow the solution of thespecies mass conservation equationsfor systems involving multiple species.Moreover, we began implementing theneeded framework in GOMA forsolving the pair of Poisson equationsthat describe the electrical potentialsin the molten electrolyte and the solidelectrode. In short, we accomplishedsignificant code development work inboth GOMA and the condensed-phaseversion of CHEMKIN. This sets thestage for developing an integratedcapability based on GOMA andCHEMKIN for modeling the complexchemical/physical phenomena in-volved in thermal batteries.


3508.230

Methodology OptimalSelection of Test andSimulation Levels forProblems InvolvingComputational Simulation

B. M. Rutherford, K. F. Alvin, V. J.Romero, T. G. Trucano

The investigation of a complexsystem is often performed using datafrom system and component test resultssupplemented by computer-generatedresponses that are based on conceptualand mathematical models of thephysical system and its environment.Analysts rely on an efficient use oflimited experimental resources to testthe physical system, evaluate themodels, and ensure (to the extentpossible) that the models accuratelysimulate the system under investigation.The general problem considered here isone where only a restricted number ofphysical tests and/or system simulationscan be performed to provide the datanecessary to accomplish the projectobjectives. The levels of variables usedfor defining input scenarios, for settingsystem parameters, and for initializingother experimental options must beselected in an efficient way. Sandiadeveloped a resampling–basedapproach for performing this selection.The methodology is applicable to thedesign of variable levels for physicaltesting and/or system simulation.

(1) During the first year of thisproject we completed a literaturereview of material related to experi-mental design for large-scale systemsanalysis. This review led to a moreformal framework for definingdesirable features of an algorithmicapproach to these types of problems.

A review of our results solidified ourview that the proposed methodologywas a promising and originalapproach.

(2) Our initial proposal includedseveral components that we consid-ered tactical aspects of the approach,in that while they were integral partsof the strategic methodology, theirperfection was not required to demon-strate the potential of the algorithm.We investigated these components to alimited extent where we are satisfiedthat they function satisfactorily for thepurpose of demonstrating theapproach. They include (a) themethodology for ensuring that therepresentation of system knowledge isconsistent with that knowledge; (b)specific parametric methods forconstructing response surfaces thatare useful in engineering applications;(c) metrics that can be used tomeasure the potential informationprovided by a candidate experimentaldesign; and (d) a tuned evolutionaryalgorithm to be used for selectingcandidate designs.

(3) We began the development ofsoftware that we will use to demon-strate the approach for small- andmedium-scale problems.

Publications

Refereed

Rutherford, B. M. 1998. “A Methodol-ogy for Selecting an Optimal Experi-mental Design for the Analysis of aComplex System.” Technometrics,submitted.

Rutherford, B. M. 1998. “ImportantConsiderations in Experimental Designfor Large-Scale Simulation Analyses.”Proc. Lockheed Martin Sys. Engin. andSoftware Symp. (May).








MANUFACTURING

SCIENCE &

TECHNOLOGY

The Manufacturing Science and Technologyinvestment area develops advanced manufacturingand production technologies with an emphasis onmoving the product from the design stage to acceptedhardware. Projects that reduce cost, shorten thedesign and manufacturing cycle, and improvepredictability of products are encouraged. Projectsmust have a potential to impact the Nuclear WeaponsProgram. Activity areas include two main thrusts: (1)develop processes that enable defect and costreduction, or that enable the manufacture of emergingproduct technologies, and (2) provide new processesthat reduce product fabrication or service defects.This will reduce product development time andexpense. About 75% of critical process steps for weaponsmanufacture involve surface cleaning or preparation,making surface cleaning the most common processstep in DOE manufacturing operations. When anengineer qualifies a new solvent for weaponsmanufacture, he must rely on cumbersome laboratorytests that are expensive, repetitious, and time-consuming. After machining metals, an engineer mustremove the lubricants used in the machining process,but many cleaners that were once used are nowbanned because of ozone problems. Frequently theengineer will put the dirty part into a cleaner andmeasure the strength of the joint, yet the part willstill come to failure. In addition, overcleaning is aconcern because it may introduce contaminants intothe waste stream. Sandia is applying their computer-modelingexpertise, fracture mechanics understanding, andcleaning experience in a project titled “Investigationof the Impact of Cleaning on Adhesive Bond and theProcess Implications” to find out how clean a materialmust be to achieve a good adhesive bond.Understanding the link between surface preparationand adhesion will result in reduced cleaningdevelopment time and testing, improved bonds, andimproved manufacturability, which can be appliedto agile manufacturing tools and will help advanceproduct realization for encapsulated components.Developing a validated model for cleaning and surfacepreparation in adhesive bonding, coating,encapsulation, or painting processes would completeSandia’s capability for a process that ensures efficient,low-cost production of small lots.





3510.540

Ultra-Precise Assembly ofMicroelectromechanicalSystems (MEMS)

J. T. Feddema, M. X. Tan, M. A. Polosky,T. R. Christenson

Sandia is currently developingprocesses to make surface-machinedsilicon (Si) and LIGA (LithographieGalvanoformung Abformung, Germanfor lithography, electroforming, molding)parts with 100-micron outside dimen-sions (OD) and submicron tolerancesfor use in weapons surety devices. LIGAparts are of special interest because theyare thicker than typical surface-machined parts; they can be made ofmetals, which makes them stronger (intension) than surface-machined Si; and,when assembled, the components arenot restricted to the plane. This lastadvantage is also a disadvantage.Today, most microcomponents areassembled manually using microscopesand teleoperated precisionmechanisms—a time-consuming andtedious task. An automated assemblysystem is needed.

The goal of this project is todevelop a visual feedback and roboticcontrol system that improves positioningaccuracy and eliminates the manualassembly of LIGA components. Onepossibility is to develop fixtures for theLIGA parts and teach points to a roboticsystem to perform a repetitive motion.Unfortunately, it is difficult to buildfixtures with submicron tolerances, andit is not effective to teach points in anagile environment with a variety ofparts. Therefore, this project uses visionand force sensing in the feedback loopto pick up and assemble randomlyplaced LIGA parts. Both the vision andforce sensing allow for the assemblyoperations to be performed using

relative position information rather thanabsolute. We used computer-aideddesign (CAD) information about theparts to generate an augmented assem-bly plan that accounts for uncertaintiesand microscale effects such as electro-statics, surface tension, and van derWaals forces.

We investigated the assembly ofmassively parallel (MP) LIGA parts andthe use of multiple cameras for visualfeedback. For LIGA to be profitable, ameans of assembling multiple parts atone time is needed. For example,imagine 1000 gears attached to a wafer.By picking up the wafer and all 1000gears, aligning them with 1000 shafts,and performing the insertion opera-tion, the throughput of the assembly isincreased 1000-fold. We designed,fabricated, and tested a system thatpresses 375-micron-diameter pins in aLIGA substrate and places a 3-inch-diameter wafer of 100 LIGA gears onthe pins. We used a two-camera visionsystem to locate holes in the LIGAsubstrate, the location of the pins, thelocation of the pin insertion tool, andthe location of the gears. We demon-strated that the vision system canlocate parts within 1-micron standarddeviation. Our positioning system canthen place the parts within 0.4-micronaccuracy.

In addition, we did a shorttheoretical study and published apaper on the effects of van der Waalsand electrostatics on the grasping of1–10-micron-diameter spheres. Weconcluded that it is possible togenerate a fine-motion assemblyplanner that accounted for theseeffects during the pick-up and releaseof the parts. This is important sinceparts this size typically stick to mostall surfaces. We also implemented a2-D version of the assembly planner,but a more general 3-D version wouldrequire substantially more work.

Publications

Refereed

Feddema, J. T., and R. W. Simon. 1998.“CAD-Driven Microassembly and VisualServoing.” Proc. 1998 IEEE Internat.Conf. on Robotics and Automation(Leuven, Belgium, 16–20 May): 1212–1219.

Feddema, J. T., and R. W. Simon. 1998.“Visual Servoing and CAD-DrivenMicroassembly.” IEEE Robotics andAutomation Magazine (December).

Feddema, J. T., C. G. Keller, and R. T.Howe. 1997. “Experiments in Microma-nipulation and CAD-DrivenMicroassembly.” Proc. SPIE,Microrobotics and Microsystem Fabrica-tion 3202 (Pittsburgh, PA, 16–17October): 98–107.

Feddema, J. T., M. Polosky, T.Christenson, B. L. Spletzer, and R. W.Simon. 1998. “Micro-Gripper forAssembly of LIGA Parts.” Proc. WorldAutomation Congress ’98 ISORA(Anchorage, AK, 10–14 May): 045.1–045.8.

Other

Feddema, J. T. 1997. “Microassembly ofMicroelectromechanical Systems(MEMS) Using Visual Servoing.” TheConfluence of Vision and Control, BlockIsland Workshop on Vision and Control(Block Island, RI, 23–25 June).

Feddema, J. T., P. G. Xavier, and R. G.Brown. 1998. “Assembly Planning atthe Micro Scale.” Proc. Workshop onPrecision Manipulation at the Micro andNano Scales, IEEE Internat. Conf. onRobotics and Automation (Leuven,Belgium, 16 May): 56–69.


3510.460

Laser-Spray Fabrication forNet-Shape Rapid ProductRealization

M. E. Schlienger, M. L. Griffith, C. L.Atwood, J. E. Smugeresky

The primary purpose of thisproject is to characterize the laser-deposition process and determine thefeasibility of fabricating complex nearnet shapes directly from a computer-aided design (CAD) solid model.Although Sandia demonstrated that thelaser-spray fabrication process (laser-engineered net-shaping [LENS]) iscompatible with metal deposition forsimple geometries, using this process toproduce net-shape high-performancemetal, ceramic, and composite compo-nents in a controllable fashion is not yetfeasible. Process characterization resultsfrom the feasibility study will providedirection in developing a system tofabricate complex shapes directly from aCAD solid model. Our goal is to developa system that is robust and that providesa significant advancement in existingtechnology. Sensors must be identified,developed (where necessary), andimplemented to provide closed-loopprocess control. We must identify closed-loop powder-feed techniques to stabilizethe process. It is also necessary todevelop methodologies to slice CADsolid models to directly drive the motioncontrol. We must develop the interfacesto be interactive with sensor inputs fromthe process. Development of this processwill allow design engineers to producefunctional models of their designsdirectly from CAD files. The turnaroundtime for complex geometrical shapedparts will be hours instead of days anddays instead of months. With thereduced turnaround time, more time canbe spent on the product design phase toensure that the best component design isachieved. Maturation of this technologywill revolutionize the way the worldproduces structural components.

We used the LENS process toproduce trial forming dies, tricladjoints, and tab attachments forneutron-generator tubes.

Over the course of this project,the time to produce a cubic inch ofmaterial decreased from 8 hours tounder 3 hours with no loss of quality.Nozzle design improved such that thedevelopment and drop-in of metaldeposits on the nozzle were largelyeliminated.

We shifted sensor developmentefforts from sensing the thermalenvironment to more fully characteriz-ing the process for enhanced repeat-ability. As a result of these efforts, weimplemented coriolis flow-metertechnologies for powder mass flowdetermination. This new sensingcapability allowed a fuller character-ization of the powder feed and resultedin new insights into control method-ologies for controlling powder feed.

We designed and built a newpowder feeder. Typical designs usescrews or other moving parts incontact with the powder, an arrange-ment that results in clogging. We basedthe new design on an hourglassprinciple. Powder falls onto a rampwhere it spreads out, and a diverterselects a portion of the resultant flow.The desired powder stream is thenentrained in a carrier gas, whereas theexcess powder is recirculated to thehopper. In this fashion there are nomoving parts other than powder.

We linked the new powder feederwith the coriolis mass flow meter andan argon mass flow controller, whichwe use for the carrier gas. The gas flowis subtracted from the total mass flow,leaving powder mass flow only. Wethen compare this signal against asetpoint and use the difference toadjust the powder feeder diverter. Thepowder feeder/sensor setup allows thepowder flow to be held stable overtime.

We made substantial progress inthe processing of titanium (Ti). Ti is areactive metal that, when in the molten

state, attacks most refractory moldmaterials. As a result, Ti is difficult toinvestment-cast. Direct fabricationtechniques offer significant opportuni-ties for the production of Ti compo-nents. Work with Ti revealed that verygood properties can be obtained.

We produced graded materials,but before we had the ability toachieve good control of the powderfeeders, it was challenging. To date, wehave had to build graded parts bylayering material in the powderhopper. This technique was successful,and we produced a part thattransitioned from a stainless-steel to anickel–based alloy. The new powderfeeders will allow the mass flow ofconstituent powders to be specifiedand, as a result, graded materials willbe much easier to produce.

Research into sensor utilizationrevealed that the best way to controlthe overall process is to control thesize of the melt pool. Since thedeposition width and thickness aredirectly related to the melt poolgeometry, controlling this parameterwill stabilize the build process.Presently, changes in part geometry,distance from the substrate, powderflow, traverse speed, and laser powerall affect the bead morphology. Bymonitoring the pool size, then employ-ing appropriate techniques to keep itconstant, we will remove variabilityfrom the process. Work at VanderbiltUniversity revealed that by using videocameras to monitor the emissivity ofthe pool at two wavelengths, we candetermine a material-independentmeasure of the molten pool size. Oncewe know this parameter, we canstabilize the process.

Publications

Refereed

Ensz, M. T., L. D Harwell, and M. L.Griffith. 1998. “Software Developmentfor LENS.” Proc. 9th Solid FreeformFabrication Symp. 9 (Austin, TX, 10–12August).


Griffith, M. L., M. E. Schlienger, J. A.Brooks, L. D. Harwell, M. Essien, D.Nelson and W. Hofmeister. 1998.“Thermal Behavior in the LENSProcess.” Proc. 9th Solid FreeformFabrication Symp. 9 (Austin, TX, 10–12August).

Maziasz, P. J., E. A. Payzant, M. E.Schlienger, and K. M. McHugh. 1998.“Residual Stresses and Microstructureof H13 Steel Formed by CombiningTwo Different Direct FabricationMethods.” Scripta Materialia, accepted.

Schlienger, M. E., D. Dimos, M. Griffith,J. Michael, M. Oliver, T. Romero, and J.Smugeresky. 1998. “Near Net-ShapeProduction of Metal Components UsingLENS.” Proc. 3rd Pacific Rim Internat.Conf. on Adv. Mater. and Processing 3(Honolulu, HI, 12–16 July).

Schlienger, M. E., M. Griffith, M. Oliver,T. Romero, and J. E. Smugeresky. 1998.“Sacrificial Materials for ComplexGeometry Fabrication.” Proc. 9th SolidFreeform Fabrication Symp. 9 (Austin,TX, 10–12 August).

Other

Schlienger, E. M., M. Griffith, M. Oliver,and T. Romero. 1998. “Laser-Engi-neered Net Shaping.” Paper presentedto the Automotive Applications ofThermal Spray Technology Confer-ence, Romulus, MI, 3 June.

Schlienger, E. M., M. Griffith, M. Oliver,T. Romero, and J. E. Smugeresky. 1998.“Recent Advances in Direct Fabricationof Metal Components.” Paper pre-sented to the Materials SolutionsConference, Rosemont, IL, 12–15October.

3510.510

Solution Synthesis andProcessing of PZT Materialsfor Neutron-GeneratorApplications

J. A. Voigt, T. V. Montoya, D. L. Sipola, R.H. Moore, S. J. Lockwood, B. A. Tuttle, T.W. Scofield, J. D. Keck

Neutron-generator power suppliesrequire two unique ferroelectric materi-als, specifically lead zirconate titanate(PZT) with a zirconium-to-titanate (Zr-to-Ti) ratio of 95:5 (PZT 95/5) and PZT95/5 with a partial substitution of tin forzirconia (PSZT). These PZT formula-tions are unique to neutron generators,and there are no current U.S. suppliersof the material. Sandia has about a5-year supply of the materials preparedcommercially using a traditionalmultistep mixed-oxide processing route.There are several concerns aboutacquisition of qualified PZT and PSZTwhen the current supply runs out:(1) Will U.S. industry be willing toproduce these difficult-to-processmaterials in the limited quantitiesrequired, and, if so, can they producequalified material? (2) Past experiencehas shown that the success of thecurrent mixed-oxide process is highlydependent on the source of raw materi-als used—will the required raw materi-als be available? (3) The currentpreparation process has many powder-handling and -processing steps that areof an environmental, safety, and health(ES&H) concern because of the PbOused in their synthesis. (4) The currentprocess is extremely labor-intensive andrequires extensive in-process testing andtweaking to produce qualified material.(5) Finally, the lack of scientific under-standing of the mixed-oxide processmakes it difficult to address problemswhen they occur. Based on our pastexperience in which we successfullydeveloped and transferred to industrychemical preparation processes, we willdevelop an alternate process based on

solution chemistry to prepare the PZTpowders. We developed a process thatsatisfactorily addresses these concerns.We emphasized the underlying funda-mentals of system solution chemistryand how these fundamentals relate tothe ceramic material properties that arecritical to neutron-generator applica-tions.

Our major accomplishment wasto develop a new process for preparingPZT (ratio of zirconium to titanium of95:5, PZT 95/5) powders using thesolution synthesis approach. Whenthese powders were processed andmachined into voltage bar compo-nents, we also demonstrated that thecomponents would meet neutron-generator power supply requirementswhen explosively functionally tested.We filed a patent for the process wedeveloped. We fabricated voltage barsfrom several powder lots of materialthis year. Explosive functional testresults from several of these lotspassed all neutron-generator powersupply output requirements.

We also demonstrated that ourPZT 95/5 powder synthesis processwas highly reproducible with respectto powder properties, includingparticle size distribution and surfacearea and powder processability.

Publications

Refereed

Tuttle, B. A., J. A. Voigt, D. L. Sipola, W.R. Olson, and D. M. Goy. 1998. “Chemi-cally Prepared Lead MagnesiumNiobate Dielectrics.” Proc. Mater. Res.Soc. Symp. 495 (June) (Boston, MA, 1–5December 1997): 185–195.

Other

Tuttle, B. A., J. A. Voigt, J. Cesarano, B.H. King, and W. R. Olsen. 1998. “Chemi-cally Prepared Pb(Mg,Nb)O3 andPb(Zr,Ti)O3 Ferroelectrics.” Paperpresented to the Annual Meeting of theAmerican Ceramic Society, Cincinnati,OH, 5 May.


3510.570

Finite-Element MeshingApproached as a GlobalMinimization Process

W. R. Witkowski, V. J. Leung, J. Jung, C.R. Dohrmann

The ability to generate a finite-element (FE) mesh in an automaticfashion is becoming the key to beingable to automate the entire engineeringanalysis process. However, placing anall-hexahedron mesh on a general 3-Dbody continues to be an elusive goal.

Sandia’s approach is fundamen-tally different from any other that weknow of. We started from the premisethat the problem of placing an all-hexahedron mesh on an arbitrary 3-Dgeometry needs to be addressed from aglobal perspective. We employed aphysical analogy for the actual meshingproblem that allowed us to construct aglobal mathematical description of theproblem. The physical analogy that wesubstituted for the meshing problem wasthat of minimizing the electricalpotential for a system of chargedparticles within a charged domain (theparticles could represent either thenodes or the elements). Our work in twodimensions showed that very reason-able meshes can be obtained by usingthis method with a mesh closure rate of99% of geometries tested. Furthermore,the method is directly extendible to 3-Ddomains.

The goal of this work is to developthe technology in three dimensions to anadequate point, then pass it to themeshing groups to complete the imple-mentation. To do this we need totransfer our understanding of thisprocess for 2-D problems to the 2-Dproblem. This involves understandinghow to describe and place particles inthree dimensions and how to establish

connectivity and achieve mesh-densitytransitions.

We focused on maturing the 2-Dmeshing work and starting the exten-sion of the technique in three dimen-sions. We rewrote the 2-D prototypecode in C++ and integrated it withCoMeT to produce a more production-like code. This provided a moreefficient environment for discoveryand code testing. With improved hole-closing algorithms and reformulationof the objective function, the schemeis currently able to close 99% of thetested geometries without interven-tion. We tested both convex andconcave geometries. We also imple-mented a mathematical combinatorialapproach to perform the particleconnectivity step, and it performedquite successfully. This providesanother scheme to perform thedifficult connectivity step and isbelieved to be more robust and moreeasily extendible in three dimensions.

We are prototyping the schemefor meshing 3-D geometries. Althoughwe could not spend much time indeveloping the 3-D code, we met ourmilestones, formulated an initialfunctional, and completed the particledescription. Simple cubes can besuccessfully meshed with hexagonalduals. The meshing of more difficultgeometries may require reworking thefunctional, which we are currentlyinvestigating.

Publications

Refereed

Wolfenbarger, P., J. Jung, C. Dohrmann,W. Witkowski, M. Panthaki, and W.Gerstle. 1998. “A Global Minimization–Based, Automatic QuadrilateralMeshing Algorithm.” Proc. 7th Internat.Meshing Roundtable ’98 1 (Dearborn,MI, 26 October): 1.

3510.590

Investigation of the Impact ofCleaning on Adhesive Bondand the Process Implications

J. A. Emerson, E. D. Reedy, Jr., J. G.Curro, E. P. Lopez

Surface cleaning is the mostcommon process step in DOE manufac-turing operations—approximately 75%of AlliedSignal/Federal Manufacturing &Technologies’ (AS/FM&Ts’) criticalprocess steps for weapons manufactureinvolve surface cleaning or preparation.We do not understand the link betweena successful adhesive bond and thesurface clean performed prior toadhesion. When qualifying a newsolvent for weapons manufacture, thecleaning engineer must rely on cumber-some laboratory tests, which areexpensive, repetitious, and time-consuming. For many years, the cleaningcommunity has called for an understand-ing of “how clean is clean?” Very littlework has been done in this area since itrequires a fundamental understanding ofthe process following the clean. Thisproject, applying Sandia’s computer-modeling expertise, fracture mechanicsunderstanding, and cleaning experience,is truly innovative in that we areaddressing the issue: “How do weachieve a good adhesive bond?”Modeling has not been commonly usedto deal with cleaning processes in thepast. Understanding the link betweensurface preparation and adhesion wouldresult in reduced cleaning developmenttime and testing, improved bonds, andimproved manufacturability, and mayalso result in an understanding thatleads to improved aging. This capabilitycan ultimately be applied to agilemanufacturing tools. This project willhelp advance product realization forencapsulated components. Developing avalidated model for cleaning andsurface preparation in adhesivebonding, coating, encapsulation, orpainting processes would completeSandia’s capability for a process thatensures efficient, low-cost production ofsmall lots.


We are developing tools, involv-ing the convergence of several expertareas across Sandia, that allow therobust manufacture of bondedstructures. These tools include modelsand test techniques that can beapplied to adhesively bonded compo-nents (structural joints, weaponsubassemblies) and to encapsulatedcomponents (neutron generators,electronic packaging). By establishinga fundamental understanding of theeffect of known contaminants on thebond interface for both adhesives andencapsulants, we will enable themanufacturing complex to make iteasier for a cleaning engineer to applythis technology to weapons develop-ment, and make the work of privateindustry easier and more efficient. Thefirst year of this project had specificrequirements: develop fracture-testmethodology, characterize contamina-tion, and develop modeling tech-niques. The second year built on theserequirements by utilizing the methodsto address the issue of gaining an apriori understanding of cleaning.

A simulation modeling tech-nique, Polymer Reference InteractionSite Model applied near wall (WallPRISM), provided the capability toinclude contaminants on the surface.The process requires a moleculardescription of polymer and contami-nants as input, and the results arecritically dependent on its accuracy.We performed preliminary calculationson the effect of contamination for 1%ethanol contamination on the struc-ture of a silicone adhesive near asubstrate. This change in the PDMS(polydimethylsiloxane) structure leadsto approximately an 8% reduction inthe work of adhesion.

We based repeatable coatingsand quantitative analysis of thesurface for deposition of controlledamounts of contamination on threedeposition methods. Hexadecane isless difficult to model, whereas mineraloil represents a typical contaminantused for machining. We varied deposi-tion times in a closed environment fordifferent times and temperatures.

Time-of-flight mass spectrometry(TOF-MS) determined the uniformityand thickness of the contaminantdeposited. The contaminant was notdistributed uniformly, and it tookapproximately 48 hours for thecontaminant to saturate, or come toequilibrium. The film thickness forhexadecane after 48 hours (TOF-MS) isapproximately 15–203 (1 monolayer).Because we performed the analysis ina high vacuum, the contaminant maybe partially volatized during analysis.We analyzed sputtered aluminum (Al)glass slides after 48-hour exposure tohexadecane in a closed environmentand dipping into hexadecane followedby blowing the visible film off. Atomicforce microscopy (AFM) images for the48-hour hexadecane exposure indi-cated that the contaminant depositionwas in the form of islands or puddles;i.e., the film was not continuous. Thisdiscontinuous film was furthersupported through contact-anglehysteresis measurements. Thehexadecane coating was discontinu-ous.

We determined the effect of thecleaning process used on interfacetoughness by measuring the toughnessof an Al/epoxy interface. The tough-ness using an asymmetric doublecantilever beam (ADCB) specimen witha Brulin-cleaned Al surface is signifi-cantly greater than that with atrichloroethane (TCE)-cleaned Alsurface (~ 50% greater). BecauseBrulin is an alkaline cleaner, etching onthe microscopic level of Al may play arole in bond toughness.

The sensitivity of measuredfracture toughness to various testconditions ensured reliability of themeasurement. Interfacial toughness(measured using ADCB sample)depends on strong function of surfaceroughness; increasing by a factor offive, the surface roughness increasesfrom 1 to 5 microns. Interface cornertoughness (butt joint) is also stronglydependent on surface roughness.Surface roughening is a commontechnique used by adhesion experts toimprove the chances of achieving good

adhesion. We also investigated theeffect of bond thickness on interfacialtoughness. The dependence of buttjoint strength on bond thickness ispredictable, and the interface cornertoughness is independent of bondthickness.

We determined the work ofadhesion value for silicone/siliconeinterface by a contact mechanicstechnique known as the JKR (Johnson,Kendall, Roberts) method. Thesevalues compare within experimentalerror with recent theory and otherexperimental techniques. The interac-tion between silicone and a cleanstainless-steel surface shows adependence on surface roughness andchemical interaction. We are synthesiz-ing new silicones to study this effect inmore detail.

Publications

Refereed

Curro, J. G., J. D. Weinhold, J. D.McCoy, and A. Yethiraj. 1998. “TheStructure of Amorphous PolymersNear Surfaces: Athermal SystemsComputational and Theoretical.”Polymer Sci. 8: 159.

Reedy, Jr., E. D., and T. R. Guess. 1998.“Interface Corner Failure Analysis ofJoint Strength: Effect of AdherentStiffness.” Internat. J. Fracture, ac-cepted.

Other

Emerson, J. A., E. O’Toole, D. Zamora,and B. Poon. 1998. “Comparison ofThree Works of Adhesion Measure-ments.” Proc. 21st Ann. Mtg. of theAdhesion Soc. (Savannah, GA, 22–25February): 238–239.

Reedy, Jr., E. D., and T. R. Guess. 1998.“Use of Interface Corner StressIntensity Factors to Predict the Failureof Butt Joints.” Proc. 21st Ann. Mtg. ofthe Adhesion Soc. (Savannah, GA, 22–25February): 192–193.


3510.580

Application of ParallelMechanism Technology toManufacturing

L. F. Bieg, V. De Sapio, D. M. Kozlowski,D. L. Plymale, G. L. Benavides, D. J.Schmitt, C. King

The goal of this project is to applyhuman-like motion to the fabrication ofSandia components. Currently, DefenseProgram (DP) products are realized byprocesses and tools based on orthogonalmotion. However, the constraints oforthogonal systems have become moreapparent as component designs in-creased in complexity. In an orthogonalworld, the fabrication of complex partsrequires multiple manufacturingprocesses and setups, resulting innumerous fixture transitions. Aside fromcost, time, and quality disadvantages,orthogonal manufacturing processesalso lead to orthogonal designs. Freeingdesigners from this bias will allow newand innovative designs to be developedbased purely on component andassembly functionality.

The overall challenge is todevelop, control, and apply human-likemotion to manufacturing. Non-orthogo-nal parallel motion (NOPM) devicesmust be developed and evaluated. Weevaluated the scalability and accessi-bility of NOPM devices for fabrication,microassembly, and micropackagingapplications. The power of this para-digm cuts across the spectrum ofSandia’s design and fabrication require-ments, and applies equally well to themicro and macro environments.

Because of this project, Sandiahas become the U.S. leader in NOPMtechnology development, employing anumber of mechanisms to evaluatefuture applications. We will apply twohexapods to evaluate metal-removalapplications, a MicroDexterity Systemfor automated assembly, a prototypeRotopod for research evaluation, andother NOPM-like devices for workpieceholding and alignment.

(1) Evaluated and selected microand macro candidate applications. We

emphasized application areas of highimpact to Sandia’s missions. Thecandidate areas are micro-assembly,micro-inspection, coordinate measure-ment, automated assembly, automatedjoining, and various forms of metalremoval. We performed our evaluationby using the commercially availableNOPM systems, the Sandia-fabricatedhardware, and the kinematic anddynamic models previously developedat Sandia, National Institute of Stan-dards (NIST), and in industry. Sandiaalone had four platforms available forapplications development by the endof FY98.

(2) Developed and appliedseamless process to NOPM prototypedevice. We have the capability toseamlessly move from a computer-aided design (CAD) model to an NOPMapplication. The tool paths for machin-ing are automatically generated withenhanced algorithms, which take intoaccount the multiple degree-of-freedom (DOF) control possible withNOPM devices. We can select indi-vidual cutting tools for each partfeature, and calculate feeds and speedsbased on tool geometry, materialselection, and a cutting-sciencedatabase. Software graphically depictsthe fabrication process to pre-verifythe actual manufacturing process.

(3) Designed and built an NOPMdevice. We performed the design ofthis device using the kinematic anddynamic analysis tools previouslydeveloped, as well as the informationlearned from the evaluation of thepreviously constructed prototype. OurNOPM device, called a Rotopod, is fullymotorized and can be moved in six-DOF space under PC-computer control,using U.S.-made motion-controltechnology. Sandia also developed themotion-control software for a commer-cially available NOPM device fromMicroDexterity Systems, and evaluatedthe pros and cons of both mecha-nisms.

(4) Developed industrial anduniversity partnerships and userfacilities. Sandia is a user’s facility forperforming research to complementand enhance our work.

(5) Demonstrated and quantifiedbenefits of micro and macro applica-tions. Based on test results, wecompared the performance of SandiaNOPM prototypes to commerciallyavailable systems. We demonstratedon the existing NOPM hardwarespecific applications that establishedthe benefits of this technology. Thisproject resulted in five individualpatent applications. In support ofquantifying benefits of NOPM devicesover orthogonal systems, we activelyinteracted with NOPM builders, users,and researchers on a national andinternational level. This includedhosting the 4th Hexapod Users GroupMeeting at Sandia.

3510.610

Standard Cells forMicroelectromechanicalSystems (MEMS)

M. S. Rodgers, J. J. Allen, M. P. De Boer,V. R. Yarberry

Microelectromechanical systems(MEMS) design tends to take place by atrial-and-error approach resulting in thenecessity for several iterated fabricationruns before working MEMS devices areachieved. This precludes the devicesfrom being integrated together in asingle fabrication run or, even moreimportantly, into a single monolithicallyintegrated system design (micro-machines with microelectronics).Typically, each design starts fromscratch since no standard part defini-tions exist. This lack of standardizationand compatibility in both manufacturingprocesses and device designs is a majorfactor preventing MEMS from attainingthe same level of success as thatachieved by microelectronics. The focusof this project effort is to amass a set ofverified, useful, diverse, standardizedMEMS parts that can all be fabricated inthe same process technology (Sandia’smultilevel polysilicon surface-micromachining process). These partswill provide an appropriate range ofactuation, sensing, energy storage, and


functionality. By creating a set of diversemodules that can be fabricated togetheron the same chip, we will create alibrary of standard cells similar to thosecommon in the highly successfulintegrated circuit (IC) manufacturingindustry. We will distribute the standardcells on a compact disc (CD) that willinclude the drawing, description, photo,and video (where appropriate) of eachstandard cell along with other informa-tion and tools relevant to designingsystems in Sandia’s multilevel MEMStechnologies.

Sandia’s internal customers usedseveral of the first-generation compo-nents for developing test vehicles tostudy friction, tribology, and reliability,and to successfully demonstrateadvanced weapons surety concepts.We continued to refine these first-generation standard cells for ease ofuse, functionality, and robustness,based on input from the early Sandiacustomers and evaluation of multipleruns. One of the actuation systemsthat resulted from this work wasfeatured in the news briefs of severalmagazines, including MechanicalEngineering, Popular Science, PopularMechanics, and Discover.

The most significant accomplish-ment is that we implemented on CD acore set of standard components and amethod for checking for proper usageand/or modification of these compo-nents via the Internet from remotecustomer sites, along with our short-course materials. We designed thesetools to fully integrate with thecustomers’ existing layout software. Inaddition to the computer-aided design(CAD) definition of each component,the software includes a description,scanning electron microscope image,and in some cases a video clip of thepart in operation. This CD is now in itssecond beta undergoing evaluation bygraduate students at the University ofCalifornia at Berkeley and the Univer-sity of Wisconsin.

We also designed and submittedfor fabrication many other candidatesfor the standard parts library. Some ofthese have already emerged.

Publications

Refereed

Allen, J. J., and H. K. Schriner. 1998.“Micromachine Wedge SteppingMotor.” Proc. 1998 ASME Internat.Mechanical Engin. Congress andExpositions, accepted.

Rodgers, M. S., and J. J. Sniegowski.1998. “Five-Level Polysilicon Surface-Micromachining Technology: Applica-tion to Complex Mechanical Systems.”Tech. Digest Solid-State Sensor andActuator Workshop (Hilton Head Island,SC, 10 June): 144–149.

Rodgers, M. S., J. J. Sniegowski, S. L.Miller, and G. F. LaVigne. 1998. “Design-ing and Operation of ElectrostaticallyDriven Microengines.” Proc. 44th

Internat. Instrumentation Symp. (Reno,NV, 5 May): 56–65.

3510.660

Scripting for VideoInspection

J. T. Feddema, C. Q. Little, J. J. Carlson

Sandia’s primary mission ofensuring a safe, secure, and reliablenuclear deterrent depends critically onthe reliability of deployed components.Visual inspection of these componentsserves as the last chance to prevent adefective part from entering the stock-pile. Most of these parts are subjected tomanual visual inspection, which raisesquestions of consistency and accuracy.Even state-of-the-art commercial visualinspection systems are inadequate,because they require skilled engineers toartfully adjust camera parameters, lenssettings, lighting, and processing, whichis prohibitively expensive for small-lotmanufacturing. In this project, we fill thisresearch gap in visual inspection bydeveloping technology to automaticallyinspect parts with a video camera. Usinga computer-aided design (CAD) modelof the part, our system will automaticallydetermine camera locations, lens

settings, and illumination to make goodimages. We refer to this combination ofimaging parameters as a script, and itwill result in a movie of the parthighlighting the sections that need to beinspected. These images will beautomatically compared to CADrenderings of the part, with differencesmarked as defects. We will enhance thesystem with specialized inspectionroutines that cannot be accomplishedwith the CAD model. The result of thiswork will be a system for automaticallyinspecting parts such as neutrongenerators, printed wiring boards,semiconductor wafers, and machinedparts.

We reordered several of the tasksto assess the feasibility of the inspec-tion routines. Instead of automaticallygenerating inspection paths from CADdata, we developed a robotic inspec-tion workcell and inspection routinesfor the neutron-generator header andframe. Using image differencing, wesuccessfully showed that we can findvoids in the braze fillets as well asbraze splatter on the ceramic insula-tors. The image inspection resultsalong with electronic images of thesubassemblies can be transferred tothe project database via the Internet.We will combine these image inspec-tion results with other information ofthe brazing process (e.g., the furnacetemperature profiles) to aid theengineers who are responsible for thedesign and manufacturing of thesubassemblies. We archived the storedimages for future comparison whenthe parts are tested.

Plans are currently under way toput a production version of thissystem in Sandia’s neutron-generatorproduction facility. The initial part tobe inspected is the screen; with futuredevelopment, the same workcell willinspect the header, source, and framesubassemblies.


3510.620

Laser Wire Deposition forFully Dense Shapes

L. D. Harwell, D. O. MacCallum, M. T.Ensz, T. E. Buchheit, M. L. Griffith, V.Tikare

The purpose of this project is tocharacterize the laser wire depositionprocess (WireFeed) and develop thetechnology to fabricate complex near-netshapes directly from a computer-aideddesign (CAD) solid model. This additiveprocess will fabricate solid metal partsdirectly from the software representa-tion, thereby saving numerous steps andtime compared to current methods andtechnologies. The initial intent of thiswork is to understand the processingconditions (laser power, wire feed rate,traverse velocity) and the materialsproperties, and to model the solidifica-tion behavior of the weld pool in theWireFeed process. By understanding theexperimental and theoretical aspects forlaser wire deposition, it will be possibleto fabricate metal parts with appropriatematerial properties.

Secondly, Sandia’s goal is todevelop a system that rapidly fabricatesaccurate, complex parts. We willdevelop software to translate CAD datainto process commands for complexgeometry fabrication. We will determineprocedures to selectively depositmaterial for controlled geometryfabrication. Development of this processwill allow engineers to produce func-tional parts of their designs directly fromCAD files. The turnaround time will behours instead of days, and days insteadof months. With reduced turnaroundtime, more time can be spent on the

product design phase to ensure that thebest component design is achieved.Maturation of this technology willrevolutionize the way the world pro-duces structural components.

At the beginning of the fiscalyear, it became apparent that thecurrent hardware design of theWireFeed system would not allow forcomplex geometry fabrication. This isbecause the laser beam is broughtperpendicular to the substrate, andthe wire is fed from the side. Thisconfiguration does not maintain thesame wire insertion direction withrespect to the scanning direction. Wedetermined a novel (patent submitted)engineering concept to allow forcomplex geometry fabrication. Thenew design splits the laser beam intothree beams that reconverge to onefocal point, and the wire is fed into themiddle of the weld pool (e.g., perpen-dicular to the substrate). Wecompleted development of the newsystem, including design, fabrication,and assembly, in approximately 8months. This produced a system withfull 360-degree XY plane contouringcapability. We completed initial testingof the system and fabricated simplecylindrical shapes.

We extended the predictivemodel to a 3-D model to understandmicrostructural evolution in theWireFeed process. The model predictsthe relative 3-D grain size and shape.We are investigating potential coarsen-ing of microstructures by subsequentlayer deposition. This model alsoincorporates a new thermal weld pooltemperature model for rastering thelaser beam. We developed the weldpool temperature model for under-standing laser metal deposition

behavior (e.g., laser-engineered netshaping [LENS], WireFeed). We havebegun initial work to obtain experi-mental thermal data, near and far fromthe weld pool. We accomplish this byusing an infrared camera focused onthe part. Current, qualitative measure-ments reveal large thermal trailsduring fabrication. We will incorporatethese data into the weld pool andmicrostructural models.

Publications

Refereed

Griffith, M. L., L. D. Harwell, D. L.Greene, J. A. Romero, T. E. Buchheit, T.B. Crenshaw, and V. Tikare. 1998.“Materials and Properties of Compo-nents Formed Using the 3DWireProcess.” Advanced Materials andProcessing, Proc. 3rd Pacific Rim Internat.Conf. on Adv. Mater. and Processing I(Honolulu, HI, 12–16 June): 3074.

Other

Griffith, M. L., L. D. Harwell, D. L.Greene, J. A. Romero, T. E. Buchheit, T.B. Crenshaw, and V. Tikare. 1998. “Free-Form Fabrication of Metallic Compo-nents Using the WireFeed Process.”Paper presented to the TMS AnnualMeeting, San Antonio, TX, 16–19February.

Tikare, V., M. L. Griffith, L. D. Harwell,and M. E. Schlienger. 1998. “Simulationof the Effect of Variable TemperatureHistory on Three-Dimensional GrainGrowth During WireFeed Processing.”Paper presented to the TMS AnnualMeeting, San Antonio, TX, 16–19February.


3510.630

High-Throughput DryProcesses for Large-AreaDevices

D. S. Ruby, B. L. Silva, C. I. H. Ashby, P.A. Miller, R. J. Buss, D. J. Rieger, P. Yang,G. A. Hebner

The goal of this work is to developguidelines for high-throughput dryprocesses that can effectively replacewet processes used in manufacturing oflarge-area devices and/or batches ofmoderate-area devices. Wet processesgenerally increase worker exposure totoxic and hazardous chemicals and tendto generate large volumes of liquidhazardous waste. Successful develop-ment of high-throughput dry processingcould eliminate much of the wastestream while minimizing workerexposure. This interdisciplinary projectutilizes Sandia’s expertise in photovolta-ics, plasma processing, sensor–basedcontrols, and process modeling todevelop environmentally benignprocesses that can reduce costs, improveproduct performance, and shortenproduct realization times. We will uselarge-area commercial silicon solar cellsas the test vehicle in this program. Wewill develop a sequence of dry processesfor selective etching of the emitter,defect passivation, and deposition of theantireflection coating. Successfulcompletion of this project will providevalidated process models that can be

used in a variety of applications forsurface cleaning, selective etching, andthin-film deposition, which arenecessary for reliable small-lot productrealization systems for DefensePrograms (DP). The models will provideguidance for development of the nextgeneration of plasma reactors and newapplications.

Langmuir probe and massspectroscopy measurements havebeen performed in a SF6 etchingdischarge to provide a database forunderstanding the chemical mecha-nisms and validating the modelpredictions. We measured the electrondensity, electron temperature, ionsaturation current, ion density, andneutral radical density for a range ofplasma conditions identified asoptimum by a statistically designedmultiparameter experiment on thesolar cell etch and passivation pro-cesses. Our measurements show alarge number of radical species as wellas etch products.

Based on a survey of theliterature, we proposed a chemicalmechanism to model the SiH4 / NH3

deposition process and the SF6 etchprocess. Comparison of the SF6 etchingmodel with experimental data foretching conditions shows similartrends for several of the dominantplasma radical species. However, insome cases the agreement is not verygood, indicating that the preliminarychemical mechanisms incorporatedinto the models must be refined. We

are currently reexamining the litera-ture and our experiments to improveour models.

Empirical optimization of the SF6

etch process using a new Plasmathermreactor resulted in finding a set ofparameters that resulted in betteruniformity over larger areas and lesssurface damage than obtained previ-ously. A three-step nitride depositionprocess was found to provide bettersurface passivation than a simple one-step deposition. We conducted astatistically designed multifactorexperiment to find process parametersthat would optimize surface passiva-tion. Use of the optimum parametersresulted in a significant 7% increase insolar cell output power.

Publications

Other

Ruby, D. S., C. B. Fleddermann, M. Roy,and S. Narayanan. 1997. “Self-AlignedSelective-Emitter Plasma-Etchback andPassivation Process for Screen-PrintedSilicon Solar Cells.” Solar Energy Mater.and Solar Cells 48 (November): 255–260.

Ruby, D. S., P. Yang, S. Zaidi, S. Brueck,M. Roy, and S. Narayanan. 1998.“Improved Performance of Self-Aligned, Selective-Emitter Silicon SolarCells.” Conf. Rec. of 2nd World Conf. onPV Energy Conversion 1 (Vienna,Austria, July 6–10).


3510.640

Assuring High Reliability andProduction Readiness inLow-Volume Manufacturing

S. V. Crowder, M. F. Martin, K. S.Marlman, E. W. Collins, J. T. Spooner, A.J. Johnson

Manufacturing philosophy in thenuclear weapons complex has shifteddramatically from the regular productionand delivery of significant orders toinfrequent small orders. New weaponscomponents are produced less frequentlyand in smaller quantities. The challengeis to build much smaller lot sizes whilemaintaining the same high-reliabilitystandards. For Sandia to meet thischallenge, specific areas need moreattention, including process develop-ment and characterization with small-sample experiments, low-volumestatistical process monitoring andcontrol, and small-lot reliability, givenfew actual performance tests of theproduct. The first year of the workfocused primarily on the development ofmethods for low-volume statisticalprocess control (SPC). We also beganour study of small-sample design andrepair of experiments. In the secondyear we completed the low-volume SPCstudy and applied the methodology to abattery cathode data set as well asneutron-tube performance data. We alsocompleted the study of small-sampledesign and repair of experiments andapplied the methodology to the repair ofan ion-source experiment. In the thirdyear of the study we focused on amethodology for small-lot reliabilityassessment and applied the methodol-ogy to the production of neutron tubes.

This year’s efforts focusedprimarily in the areas of small-sampledesign of experiment and low-volume

SPC. We also proposed a new reliabilityassessment methodology.

We developed a designoptimality criterion for constructingand repairing small-sample experi-ments. The design optimality approachuses a metric called maximum predic-tion variance (MPV), a quantitativemeasure of the amount of informationcontained in an experiment. Themetric can be used to appropriatelysize an experiment. This approachleads to experiment plans that areoften much smaller than traditionalexperiment plans, so the technique isideal for small-lot production environ-ments, often resulting in great costsavings. We identified a statisticalsoftware package, STATISTICA, toconstruct these nonstandard designsand used the approach to repair asmall-sample ion-source experiment.

The second major accomplish-ment was in the area of low-volumeSPC. We completed our research intosample size requirements for the SPCalgorithm that we developed. We wereable to show that the algorithm can beapplied to as few as 25–50 samples,compared to 100–200 samples recom-mended for traditional SPC. We wrotethe statistical software required toimplement the algorithm in FORTRAN,C, and MATLAB code. We applied thetechnique to battery-cathode data aswell as neutron-tube performancedata.

Publications

Refereed

Crowder, S. V., and L. Eshleman. 1998.“Small-Sample Properties of anAdaptive Filter with Application toLow-Volume Statistical ProcessControl.” J. Quality Technol., submit-ted.

3510.670

Advanced MachiningProcesses forMicrofabrication

G. L. Benavides, A. N. Campbell, B. L.Doyle, P. Yang, D. P. Adams, D. L.Plymale

An important product realizationgoal for Sandia is to reduce the volumeof weapon components by 50%. Sandiais a national leader in microfabricationtechnologies such as silicon–basedmicroelectromechanical systems(MEMS) and electroformable metal–based LIGA (German for lithography,electroforming, molding). However,there are micromachining technologyvoids that need to be filled to meet thevolume reduction goal. Sandia mustattain capabilities unavailable throughLIGA, i.e., to fabricate subminiatureparts from nonelectroformable metals orceramics and to micromachinenonplanar features. We will augment ourmicrofabrication technologies byresearching novel applications ofexcimer laser and focused ion beam(FIB) machines. The process ofmicromachining by material removal isnew to both Sandia and industry and, assuch, presents opportunities for thecreation of intellectual property.

We will use the Sandia FIB tofabricate microsize features in desirablematerials and to fabricate steelmicrotools for use in conventionalprocesses such as drilling, milling, andsinker electro-discharge machining(EDM). The FIB beam width of 100nanometers can create 0.5-micron-sizefeatures in high-strength/high-tempera-ture metals and ceramics. We plan tocollaborate with Louisiana TechUniversity (LTU) on FIB/micromachining research.


We will use the excimer laser tofabricate microsize features in materialsincluding ceramics, magnetic materials,and polymers. This ultraviolet (UV)laser ablation process removes materialwithout sample melting, providing theprecision essential to fabricate high-aspect-ratio microstructures. We directlymachine thin sheet materials into 3-Dstructures. Unlike LIGA, this process willnot require a synchrotron, wet chemicalprocess, or planarization.

We accomplished the followingin FY98:

(1) Prepared the excimer laserfor the micromachining of materials.

(2) Prepared the FIB machine formicromachining.

(3) Identified microtools forfabrication.

(4) Collaborated with LTU on thedevelopment of microtools.

(5) Fabricated the microtoolsidentified above using an ion source.

(6) Machined holes in polymersand ceramics using the excimer laser.

(7) Characterized microholedimensions and surface quality.

We made two major break-throughs:

(1) Acquired an FIB machinethrough our collaboration with LTU,which gives us a micromachiningcapability we did not have.

(2) Successfully machinedacrylic, aluminum, and brass with a.001-inch-diameter end mill. This is thefirst time that a .001-inch hexagon endmill has been used to machine metal.Prior to using the .001-inch end mill,the smallest end mill used at Sandiawas .005-inch diameter.

We also purchased a new micro-EDM. Because of the success ofmicromilling with the .001-inch endmill, we will fabricate channels for theMicro-Chem-Lab-on-a-Chip technology.There is interest in our capability tomicromachine microholes with ourexcimer laser.

3510.680

Fusion of Product andProcess Data Using Real-Time Streaming Visualization

V. De Sapio, G. K. Hicken, J. M. Baldwin,R. G. Hillaire, T. R. Walker, D. A.Sheaffer, Jr., C. M. Leonard, Jr.

This work will involve the use ofsocket input/output (I/O) to communi-cate in-process data from a machinetool, welding system, or coordinatemeasuring machine (CMM) in real-timeto a simulation package. For example,Sandia will send machining datastreams associated with force oracoustic emission sensors, as well aspositional data, in process to a simula-tion software package. We will fusethese data streams in real-time to partgeometry that constantly changes asmaterial is removed. In addition tosensor data streams, process andmachine models running in softwareexternal to the main simulation enginewill be able to feed model–based data inreal time to the simulation environment.The process models will address thephysics of the specific unit process. Themachine models will address thekinematic behavior of the machine(s)involved in the process. We will capturethe resulting dynamic process overlayand export the motion paths as paramet-ric kinematic data. We will thendisseminate the VRML 2.0 data filesrepresenting this information via anelectronic traveler (PRIME) client. Weare proposing an additional approach toclient-side access to the simulations andprocess data representations. This usesobject-oriented behavioral components

called Simlets, as well as a number ofexisting technologies including OpenInventor/VRML (virtual reality modelinglanguage) for graphics rendering, JavaApplets, and ActiveX.

We developed file parsers toprocess raw data from both inspectionreports and milling machine andwelder data-acquisition systems.

We developed custom applica-tions using the Express developmentenvironment for visualization applica-tions. The metrology applicationincorporates custom file readers forimporting the metrology data files(.met) and the feature files (.fet). Themilling and welding applicationsincorporate custom file readers forimporting the scalar hyperpoint datafiles (.shd). We incorporated a DXFimport module and a VRML exportmodule into all of the process visual-ization applications.

We developed ActiveX Web-browser components for the metrol-ogy, milling, and welding visualizationapplications.

A Web interface is complete forthe metrology application. We wroteCGI (common gateway interface) PERLscripts to automate the retrieval andparsing of raw inspection data. We arewriting the hypertext markup language(HTML) templates and CGI scripts forall applications to automate theretrieval of overlaid process-modeldata (in VRML format) via the Web.

We will complete the integrationof the Web–based process visualiza-tion front end with the PRIMEelectronic traveler. This is still inprocess but will be completed con-currently with early second-yearactivities.


3510.690

Advanced ProductionPlanning Models

D. A. Jones, W. E. Hart, C. A. Phillips

Advanced production planningand scheduling tools are vital for theNuclear Weapons Complex (NWC) tosatisfy its mission with increasinglyconstrained resources. In addition,stockpile life-extension programmanagers and weapons designers needto be able to see how their new designswill affect production, especiallyresource requirements and logistics. Toaddress these issues, Sandia is develop-ing advanced production planning andscheduling tools focused on task–basedoperations at NWC sites; i.e., operationsthat require a series of tasks to beperformed in a particular sequence, andwhere various sets of tasks compete forcommon resources. The underlyingmathematical problem addressed in thisproject is extremely complicated, andour objective is to develop effectiveheuristics; i.e., methods to obtainapproximately optimal plans/schedulesquickly. Our technical approachinvolves four major steps: (1) identifyways to model important site-specificelements of production planning and

scheduling, (2) develop a mathematicalformulation of enhanced planning/scheduling models, (3) develop exactsolutions to planning/schedulingproblems for several sets of test data tocreate benchmarks, and (4) developeffective heuristics for achieving rapidapproximate solutions, and comparetheir performance to the exact solutions.The end product from this project will bea suite of solvers that will provideadvanced production planning andscheduling capability for many differentsites within the NWC.

We developed a highly innova-tive modeling approach for task–basedproduction planning and schedulingproblems. This formulation has directapplication to planning of stockpileevaluation activities at Pantex, as wellas future stockpile life-extensionprogram activities.

The new formulation is anoptimization model that uses onlycontinuous variables, avoiding the useof integer variables. From a conceptualstandpoint, three main featuresdistinguish this formulation fromprevious approaches. First, its timeperiods can have variable lengths. Thismeans that monthly (weekly or other)boundaries can be matched precisely.Second, the principal choice variables

are the starting times for each task,rather than using a period index for astart time, as is done in integerprogramming approaches. Third, theassignment of tasks to resources(facilities and technicians) accuratelyreflects the character of feasibleassignments at production facilities inthe NWC.

Test results based on actual dataare very encouraging that this newapproach to task–based productionscheduling will be a major break-through for large-scale, realisticscheduling problems in a variety ofproduction settings. We created afundamentally different way of viewingand formulating math programs forthis class of problems, and we believethis approach (after further testingand development in conjunction withadvanced computation on parallelcomputers) will be the basis for a newgeneration of advanced productionplanning and scheduling models.

Publications

Other

Kjeldgaard, E. A. 1998. “AdvancedProduction Planning Models.” Bro-chure, Sandia National Laboratories(12 December).








LIFE-CYCLE

SYSTEMS

ENGINEERING

Life-Cycle Systems Engineering studies trace theentire life cycle of a product, considering affordability,performance, design, testing, production, fieldoperation and maintenance, and product retirement,and encourage development of modeling andsimulation prototypes that support life-cycle studies.Studies may involve collaboration with other LDRDareas and with national security programs. This activity comprises projects in five areas: (1)developing single systems that engineers at all stagesof product development can use; (2) deepening theunderstanding of how production technology affectsproduct performance, cost, and usefulness; (3) addingknowledge and capabilities to product development;(4) creating technologies that allow workers to focuson innovation by relieving them of activities that canbe automated; and (5) developing innovativecollaborative arrangements to create long-distancework environments as productive as those where allworkers share the same site. Any design or production system requires com-plete, realistic, easy-to-understand documentationso manufacturers can design and produce aconsistent, high-quality product cost-effectively, butthe cost of high-quality documentation is staggering,and the necessary skills are not always available.Sandia is developing automatic tools to help engineersdevelop and refine design concepts and generateinformation that others can use to produce the designand to incorporate design changes faster and moreeasily. The Internet is especially suited to sharingthe graphical, multilayered design used withcomputer-aided design and engineering (CAD/CAE). Sandia’s work in automated multimedia documentcreation began with its award-winning assemblyplanning and visualization software tool calledArchimedes. Engineers use Archimedes toautomatically determine optimal assembly sequencesfor mechanical devices. Sandia’s first multimediatools automatically turned Archimedes’ output intoWeb-ready multimedia documents that includedmovies of each assembly step. Sandia applied thesedocument-creation techniques to both commercialand in-house robotic simulation software packages,letting engineers quickly turn simulations, from robotsto entire factories, into Web-ready 3-D animationsand movies. Sandia now uses these tools to relay design simu-lations via the Internet to customers outside Sandia,and customers are spending less time and moneytraveling to Sandia while getting better answers morequickly and less expensively via the Internet.





3511.080

Enabling Human Skills withCooperative Automation

D. J. Schmitt, T. S. Gladwell, R. J.Anderson

This project is developing thesensing and intelligent controls technolo-gies required to create cooperativeautomated assistants. Sandia is doingthis by developing workspace sensorsystems to dynamically track movingobjects such that an automated systemcan be continuously aware of thelocation of the human within theworkspace. We are using data from thesensing systems to allow the automatedsystem to not only safely co-exist withthe human, but also to cooperate toperform tasks. This project is producing,for the first time, the ability of humansand automated systems to cooperate toperform tasks within the same work-space. The intent is to enable efficienttask execution by simultaneouslyutilizing the best skills of the human andmachine to perform a required task.This cooperative automation frees thehuman from mundane and hazardoustasks and allows the human to performthe more insightful operations such astask supervision. This technology willoffer the potential for reducing person-nel requirements in battlefield andbattleship operations by providingcooperative automated assistants, andby allowing multiple cooperativesystems to be directed by a singleindividual.

We are focusing on developingthe sensor systems and controlarchitectures required for human androbot interaction. Three modes ofinteraction are important: tracking,engagement, and guidance. Trackinginvolves dynamically following the

location of a human as he approachesthe robot’s workspace. Engagementinvolves intersecting the workspace ofthe human and robot so that interac-tion can occur. Guidance involves thehuman physically directing the motionof the robot. We are developing avision–based system for tracking,electromagnetic sensors for engage-ment, and a force sensor for guidance.We are now interfacing these sensorsystems to a pedestal-style robot todemonstrate each of these interactionmodes. The pedestal robot we chosehas two separate computer control-lers, which are providing flexibility inthe control architecture development.One system uses the native controllerand provides human/robot coopera-tion capabilities suitable to the largeinstalled base of these robots. Theother controller is a PC–based, open-architecture controller, and is provid-ing the capability to utilize the SMARTarchitecture developed at Sandia.SMART provides a more sophisticatedand flexible control system that allowsus to implement higher-level human/robot interactions, and provides ameans to implement these behaviorson other automated systems. Weimplemented demonstrations of eachof these capabilities. One demonstra-tion uses the vision system to trackand engage a human such that anobject can be exchanged with therobot. This demonstration alsoincludes a structured lighting systemto map the location of critical objectsin the workcell. The second demon-stration shows the capability of thePolhemus sensor to finely resolve thelocation of a person’s hand for moreprecise engagement. A third demon-stration shows the use of the forcesensor such that a person can guidethe robot to a location for taskexecution.

The architecture for enabling thehuman/robot cooperative behavior inthe vision–based demonstrationutilizes a supervisory controlcomputer to control data flow betweenthe vision system and the robot. Wedefined a series of states that arebased on the human’s location withinthe monitored workspace (e.g.,automatic motion, track human,engage human, inspect object, emer-gency stop). The supervisor monitorsthe incoming vision data, determinesthe state the robot should be in, andcommunicates the state and visiondata to the robot. The robot interpretsand acts on the communicated visiondata differently based on the state. Thesupervisor ensures that the states areimplemented in the proper order for asafe interaction. The robot’s transitionthrough different behavior statesestablishes a dialog between robot andhuman. When no humans are inproximity to a robot, the robot canoperate at high speed along optimalpaths. When a human approaches theworkcell, the robot stops its currenttask, slows its speed, and responds tothe human presence in a nonthreaten-ing manner. For example, in a materialhand-off operation, the robot maymirror the operator’s position,tracking the operator’s position acrossthe workcell and approaching theoperator only when the operatorapproaches the robot. Once theoperator passes into a transition zone,the robot comes to a complete stop.

We reviewed the recent literaturerelated to human and robot interac-tions. Trends in this research includestudying and modeling humanbehavior such that the behavior canbe emulated in automated systems,and co-manipulation of objects by ahuman and robot.


3511.010

Automatic Generation ofMultimedia Documentationfor Assembly Operations

M. J. McDonald

Realistic, easy-to-understand, andcomplete documentation greatlyfacilitates designing and manufacturingof consistent, high-quality products. Thisis especially true in Sandia’s high-consequence, low-volume design andproduction environments. Unfortunately,document production costs often limitthe amount of documentation produced.This project built new technologies toreduce those costs.

The World Wide Web provideseffective solutions for efficientlydistributing high-quality, multilayeredgraphical information typical in engi-neering. Importantly, Web movies havebecome more accessible than videos,and modern virtual reality modelinglanguage (VRML) viewing software cannow support many 3-D visualizationneeds.

A first step in reducing documenta-tion costs is to harness computer-aideddesign (CAD) and Web technologies toefficiently produce the needed docu-ments. This project first leveragedSandia’s automated assembly-planningtechnology, called Archimedes, todevelop a software tool that convertsCAD models of devices being manufac-tured into multimedia documents of thesteps required to assemble the products.The project then developed translatorsthat could produce digital movies and 3-D VRML animations from Sandia(Umbra) and commercial (DenebsEnvision) simulation tools. Now,engineers can generate multimediadocuments of assembly processes,robotic manufacturing processes, andsmall smart machine motions wheneverthey run a simulation.

The second step was to developelectronic document review mechanismsto integrate peer and customer reviewwith Web-served digital documentation.This effort developed three multimediafeedback systems. Each system allowspeople to make context-sensitive

comments about specific Web contentand electronically ties the commentsback to the Web content being refer-enced. The first ties comments tospecific Web pages, the second ties thecomments to specific frames of digitalmovies, and the third ties the commentsto specific times and viewpoints within3-D animations.

To validate the tools, this projecttested these technologies against real-world applications in neutron-generatorproduction and robotic system design.We found that the tools reduced multi-media documentation costs andprovided effective support for reviewingWeb reports, movies, and VRMLanimations.

We researched existing multime-dia, assembly, and engineeringdocumentation software tools andconcluded that Web–based documen-tation approaches held the mostpromise as delivery tools. To betterground this work, we establishedrelationships with potential multi-media assembly and engineeringdocumentation authors at Sandia inthe neutron-generator fabrication andtied development to their problems.We then prototyped example multi-media assembly documents andsocialized the processes and results.We extended the Archimedes systemto directly output Web-viewable moviefiles that we used in Web and MicrosoftWord documents. These results led toa team effort to produce a second-generation prototype tied into theproduct data management (PDM)document control system. We devel-oped a prototype extension toArchimedes to directly generate basicWeb-viewable documentation includ-ing text, still graphics, and movies. Wedeveloped an addition, a VRML 1.0(static model) translator for viewingArchimedes outputs. We establishedrelationships with neutron-generatorproduction personnel at Sandia and arelated effort at Pantex. We publishedArchimedes and multimedia efforts inthe form of Web–based reports andexamples.

This work showed that multi-media documents had broad use inboth production and engineering, and

we identified the need to support abroader range of simulation andanalytical tools. To address theseissues, we identified and testedexisting technologies, includingmodern hypertext markup language(HTML) editors, commercial CAD-to-movie and VRML 1.0 translators,imaging tools, and portable documentformat (PDF) documents for use inengineering documentation. At thesame time, we found good static scenegeneration but a lack of developmentor research in animated VRML models.

Through this evaluation weidentified that the then-emergingVRML 2.0 standard could support the3-D graphic animation needs inengineering and production. Byleveraging past graphic file translationwork done at Sandia, and intimateknowledge of the in-core memorystructure of two simulators, wedeveloped in-core translators for onecommercial (Denebs Envision) and oneSandia-developed (Umbra) simulator.We can run the resulting softwareworks in the background to automati-cally generate animation informationwhile running simulations. Later, wetranslate this information and save itinto a VRML file that we can then runon any VRML viewer, publish it on aWeb site, or e-mail it to a customer. Inaddition, we can run the file withinInternet Explorer and in conjunctionwith a Java–based applet that wedeveloped to provide VCR-like anima-tion control.

We socialized these results andpractices by installing and trainingengineers in its use and by applyingthe tools against systems-engineeringprojects, including one for automatedradioactive source unpacking. Inaddition, we used materials generatedearly in this effort in collaborationwith New Mexico Tech.

Through these applications, weidentified the further need to tiedetailed comments back to the specificWeb pages, movie frames, or VRMLanimation viewpoints to which theyreferred. Unfortunately, the existingmethod for tying comments to Webviews was by e-mailing Web pages or


screen copies of animations. WhileInternet discussion groups couldprovide appropriate distributionmechanisms, we needed bettersolutions.

To address these review needs,we developed three multimediafeedback systems. Each system allowspeople to make context-sensitivecomments about specific Web contentand electronically ties the commentsback to the Web content being refer-enced. The first system ties commentsto specific Web pages, the secondsystem ties the comments to specificframes of digital movies, and the thirdties the comments to specific timesand viewpoints within 3-D animations.

The result of this work is a newapproach for building documentationinto the design process. These toolsare already in use in a variety ofprojects and will be extended to meetthe evolving opportunities of multime-dia technologies.

Publications

Refereed

McDonald, M., E. Gottlieb, C. Slutter,and S. Gladwell. 1998. “MultimediaFeedback Systems for Robot SystemsEngineering.” Proc. ANS 8th Topical onRobotics and Remote Systems, ac-cepted.

3511.020

Distributed Life-Cycle Modelsin Enterprise Simulations toAnswer System Questions

M. M. Johnson, H. R. Ammerlahn, A. S.Yoshimura, T. D. Plantenga, E. K. Lemen

The goal of this project is to pulltogether an integrated Sandia systemsstory about enterprise modeling andsimulation. This requires developmentof a distributed computing softwareframework that can integrate variousSandia planning models into a singlediscrete-event simulation. The frame-work must address special issues

important to potential Sandia customers,including the definition of softwareinterfaces, distributed operation onmultiple heterogeneous platforms,enforcement of multilevel accessrestrictions that derive from differinguser classes, and coordination of localplanning/scheduling models into aunified enterprise-wide life-cyclesimulation. The software framework andassociated interfaces will be a general-purpose package suitable for manydifferent customers.

The project will also construct aclassified life-cycle model of the DOEnuclear weapons complex (NWC) andpopulate it with enough real informationto demonstrate the capabilities of anenterprise simulation. A fully populatedenterprise model will provide stockpilemanagers with an important tool forplanning and decision analysis.

We completed a general-purpose,distributed, discrete-event simulationsoftware package called IDES (Infra-structure for Distributed EnterpriseSimulations). We wrote IDES in Java forplatform independence and tested iton a variety of heterogeneous com-puter networks. The IDES frameworkfollows a philosophy of open extensi-bility: Diverse participants in anenterprise simulation contribute theirexpertise through individual software“confederate models.” Each confeder-ate plans/simulates its portion of theenterprise through a simple applica-tion programming interface (API). IDESlinks the confederates into a consis-tent, unified, discrete-event simulationfor answering enterprise systemquestions. The IDES framework alsoexports user inputs and outputs,authenticates database queries,coordinates multiple interactive users,and supports computational load-balancing across an arbitrary networkof machines.

The simulation frameworkprovides multilevel authenticationthrough a novel, secure, computingenvironment developed under thisproject. We extended conventionalrole–based access control (RBAC) toprovide a distributed implementation

(D-RBAC). The D-RBAC model allowseach confederate to control how muchinformation is exported to each userlogged into an enterprise simulation. Aconfederate submodel can participateprivately (exporting only minimaltransaction-level data), publicly(allowing external control of internalmodel parameters), or at any level inbetween. Confederates also determinetheir visual appearance to otherenterprise participants through ageneral Java API. This API provides ahigh degree of flexibility to confederatedesigners, but integrates the outputwith a consistent look and feel toprovide a friendly interface for allusers.

IDES provides a test-bed andsimple examples for simulationdevelopers. The project also helpedsupport creation of a detailed enter-prise simulation of the DOE NWCcalled CoMPASS (Confederation ofModels to Perform Assessments inStockpile Stewardship). CoMPASSbrings together stockpile surveillancedatabases and production planningmodels from Pantex, Y-12, AlliedSignalat Kansas City, Sandia, and othersources. Each of these is a confederatewith specific security and authentica-tion requirements addressed by the D-RBAC model. We wrapped and inte-grated confederate software modelsaccording to the IDES API. The IDES–based CoMPASS simulation will answerstockpile life-cycle questions fromdifferent perspectives, utilizingdifferent confederate inputs. Theprototype product has already beensuccessful in developing relatedbusiness for individual weaponssystem programs.

Publications

Refereed

Johnson, M. M., A. S. Yoshimura, andD. M. Nicol. 1997. “The IDES Frame-work: A Case Study in Development ofa Parallel Discrete-Event SimulationSystem.” Proc. 1997 Winter SimulationConf. 1 (Atlanta, GA, December): 93–99.


3511.040

Immersive CAD

A. L. Ames, J. L. Brazee, E. A. Peña, C.Q. Little, D. Hickerson

Recent widespread acceptance ofsolid modeling in product realization islargely due to improved user interfaces.While these interfaces are sufficient fordetailed design, they are provinginadequate for conceptual design. The“back-of-the-envelope” is still theconcept modeler of choice. Current solidmodelers require complete specificationof product geometry, which is awkwardin early stages of design. Engineers wantto see, feel, and manipulate theirdesigns, but are frustrated by over-whelming data complexity (the “hairballeffect”).

This project will develop aprototype immersive computer-aideddesign (CAD) environment. The workinvolves four fundamental concerns: (1)developing a set of interaction mecha-nisms that provide easy, natural productmodel editing, (2) providing a means forsupporting design constraints, (3)managing the wealth of product informa-tion, and (4) dealing with the radicaldifference in time scales betweenrendering rates and solid modelerspeeds to permit real-time modelmanipulation. Editing operations thatwork in multiple tightly coupled repre-sentations (design features, constraints,boundary representation, and facets) ona parallel architecture address perfor-mance requirements, while Sandia willuse virtual reality (VR) techniques toaddress interface concerns. This worksteps beyond any current VR CADsystem by producing constrainedfeature–based boundary-representationsolid models. This project has thepotential to impact every Sandia projectinvolving the design of mechanical partsand assemblies. The ability to moreeasily synthesize and visualize designconcepts, without complete detailing,will encourage more concepts to beevaluated, yielding better product.Including analyzability and

manufacturability constraints in theinterface will deliver better products tomarket faster.

(1) We developed a mechanismfor detecting topology change duringsolid-model editing operations usingC-Space Toolkit and Gilbert’s algo-rithm.

(2) We developed mechanismsfor performing topology-invariantediting of solids. Such editing permitsrotation, translation, and scaling offaces within the solid model with onlyvery minimal local recomputation. Theapproach permits real-time editing.

(3) We demonstrated feature–based topology editing. Such editingpermits topology-changing edits to beperformed, but exacts a penaltysimilar to current CAD systems. Use oftopology-change-detection algorithmsminimizes impact of this algorithm torelatively infrequent occurrences.

(4) We partially developedalgorithms for topology-changingoperations. Fast topology changes arepossible with minimal time penaltythrough the use of persistent datastructures. We can minimize geometricoperations again through the use ofC-Space Toolkit distance computa-tions. We showed it is possible forsolid-modeling operations to occur intime proportional to the magnitude ofthe change, rather than in timeproportional to the complexity of theentire model.

(5) We developed object selec-tion and manipulation algorithms topermit immersive editing of solidobjects.

(6) We demonstrated usefulnessof this technology compared to legacyCAD systems and showed profoundspeed improvements.

Publications

Other

Ames, A. L., E. Peña, J. Brazee, and D.Hickerson. 1998. “Immersive CAD.”Sandia Technical Report, in prepara-tion.

3511.050

Automatic Planning of Life-Cycle Assembly Processes

T. L. Calton, G. A. Laguna, J. C. Trinkle,R. R. Peters, E. A. Mitchell, R. G. Brown

Sandia today expends more efforton upgrade and maintenance projectsthan on clean-slate designs. However,commercial computer-aided design(CAD) tools are better suited to initialproduct design. Computer-aided analy-sis, optimization, and visualization oflife-cycle assembly processes based onthe product CAD data can help ensureaccuracy and reduce effort expended inplanning these processes for existingproducts and provide design-for-lifecycleanalysis for new designs. We will adaptand apply Sandia’s automated assembly-planning and design-for-assemblycapabilities to later life-cycle assemblyprocesses of a system, including service,field repair, and upgrade. The systemwill support replacing one or severalsubassemblies, gaining access forinspections, and optimizing disassemblycosts.

Automated simulation andanalysis tools resulting from this projectcan provide expert advice to fieldpersonnel needing to (remotely)disassemble a terrorist device and canhave significant impact in the reductionof physical mock-ups required fortraining personnel in maintenanceoperations and depot repair.

We made significant achieve-ments in each of the work areas: (1)improvement in the Design forLifecycle (DFLC) cost module, (2)research and development of specificoptimization algorithms addressingboth nondestructive and destructive(dis)assembly planning, (3) codeefficiencies, (4) publications, and (5)business development.

• Upgrades to DFLC module. Lastyear we developed a prototype modulethat could calculate the cost, in dollarsor other units, for remove-and-replace


assembly operations. This is a power-ful tool for comparing costs of compet-ing designs, upgrade versus newproduct. We expanded the capabilitiesto (1) include input from genericdatabases, (2) store and retrievepreviously defined assembly, dis-assembly, and cost-analysis informa-tion simultaneously, and (3) allow theuser to edit cost on the fly. Upgradesallow users to optimize sequencesbased on real dollars and time.

• Automated disassembly R&D.We made substantial progress in bothnondestructive and destructive areasfor automatically planning sequences.We added an optimizing algorithm forpart-removal by implementing aspecial-purpose search strategy forpartial disassembly tasks. The algo-rithm uses a simulated-annealing-likeprocess to distill locally shortestdisassembly plans from the longerplans provided by the general-purposeplanner. This planner enablesArchimedes to find optimal partialdisassembly/service plans in a fewminutes in most cases, for assembliesmuch larger than the 20–25-part limitthat was the previous limit, and bringsthis kind of planning into the realm ofpossibility for assembling hundreds ofparts.

In some applications, operationsthat destroy parts, such as cutting,tearing, or melting, are acceptable indisassembly. Destructive operationshave complex and sometimes unpre-dictable geometric effects, but in manycases they are the most effectivemethods of disassembly. We are in theprocess of developing algorithms thatcan automatically identify assemblyoperations requiring destructivedisassembly. We are currently incorpo-rating additional manufacturingprocesses into the code.

We are presently working toextend the core planning capabilitiesto include compound linear remove-and-replace trajectories. However, dueto the difficulties associated with both

the geometric complexity and theplanning complexity, we expect onlyminimal progress this year. Thedifficulties occur with the recognitionof convergence for a series of linearmovements that will allow a compo-nent to be removed. Since the numberof interactions between any pair ofparts (with reasonable complexity) islimited, the number of simple lineartrajectories that need to be consideredto determine whether one exists forremoval of a particular part from anassembly is effectively finite. Theseinteractions (simple linear trajecto-ries) are understood, and the currentArchimedes planner approximates theset of possible trajectories. However,for a given class of compound trajecto-ries we need to formulate finite sets ofequivalent trajectories so that it is notnecessary to consider an infinite set ofpossibilities.

As a result of last year’s data,translation capabilities, and thepromise of an effective cost module,more than 35 companies haveexpressed interest in the life-cycleplanning capabilities.

Publications

Refereed

Calton, T. L., R. G. Brown, and R. R.Peters. 1998. “Automated Analysis forLifecycle Assembly Processes.” Proc.2nd Internat. Conf. on Engin. Design andAutomation 1 (December) (Maui, HI,August): 1–10.

Calton, T. L., R. Jones, and R. Wilson.1998. “On Constraints and QualityMeasures in Assembly Planning.” IEEETrans. on Robotics and Automation,accepted.

Calton, T. L., R. R. Peters, and R. Jones.1997. “Automated Assembly andFixture Planning at Sandia NationalLaboratories.” Assembly Automation,Internat. J. Assembly Technol. andManagement 17 (November): 201–205.

Other

Calton, T. L. 1998. “ArchimedesConsortium Workshop.” Presentationto the Archimedes ConsortiumWorkshop, Albuquerque, NM, 2–3March.

Calton, T. L. 1998. “Automated Assem-bly Planning—The Archimedes Tool.”Invited talk/demonstration to theInternational Tour of Hexapod Users,Albuquerque, NM, 19 June.

Calton, T. L. 1998. “Automated Assem-bly Planning—The Archimedes Tool.”Invited talk to be presented toRedstone Arsenal, Huntsville, AL, 1999.

Calton, T. L. 1998. “Automated Assem-bly Planning—The Archimedes Tool.”Invited talk to the Ford Expo, Detroit,MI, 3 November.

Calton, T. L. 1998. “Automated Assem-bly Planning—The Archimedes Tool.”Paper presented to the Joint Un-manned Systems Technology Work-shop, Panama City, FL, 22–23 Septem-ber.

Calton, T. L. 1998. “Automated Assem-bly Planning—The Archimedes Tool.”Presentation to meeting at RaytheonSystems Company, Tucson, AZ, 3February.

Calton, T. L. 1998. “International TripReport.” Trip report on 1998 IEEEInternational Conference on Roboticsand Automation (May).

Calton, T. L., R. E. Jones, M. McDonald,P. Bennett, B. Anderson, R. G. Brown,R. R. Peters, Y. Hwang, F. Oppel, R.Lafarge, and A. Ames. 1997. “Simula-tion and Off-line Programming atSandia’s Intelligent Systems andRobotics Center.” Proc. RIA Workshop(Detroit, MI, 21–23 October).


3511.070

Analysis of Very LargeAssemblies

R. G. Brown

Sandia’s Archimedes automatedassembly analysis system has now beenapplied successfully to several largeindustrial and weapon assemblies.While Archimedes represents the state-of-the-art in automated assembly-planning software, these applicationsshow the limitations of the system andthe need for extensive modifications tosupport practical analysis of assemblieswith several hundred to a few thousandparts. We believe that there is substan-tial potential for enhancing Archimedesto routinely handle much larger modelsand/or to handle more modestly sizedassemblies much faster. Such a matureassembly analysis capability is neededto support routine application toindustrial assemblies that now over-stress the system, such as full nuclearweapon assemblies or full-scale aero-space or military vehicles.

Two arenas in which Archimedesmight prove to be of interest are that ofautomating shipboard maintenancetasks and that of battlefield-conditioncustom assembly of autonomous andteleoperated vehicular robots. In thecase of automated shipboard mainte-nance tasks, Archimedes could beinvaluable for evaluating the feasibilityand efficiency of various designs forshipboard systems, relative to the costand difficulty of automating mainte-

nance and service tasks on thosesystems. In the case of battlefield roboticvehicles, again the evaluation of designsand design strategies could be quitevaluable, as would the ability togenerate multimedia training documen-tation for the soldiers working with therobots. Since the shipboard systems andlikely the vehicular robots tend to bequite complex, Archimedes needs to beable to handle large systems quickly andefficiently.

We made significant progress inreducing all of the three mainresources identified as barriers toapplication of the Archimedesassembly-planning system to verylarge assemblies: memory utilization,contact analysis computation time,and planning time. Furthermore, weadded capabilities enabling the user tomore quickly and easily interact withlarge assemblies, in terms of providingmating and manufacturing overrides,and assembly constraints. The usercan now interact with an assembly atthe subassembly level, establishingappropriate constraints and overrides,and have those constraints and over-rides show up at the full assemblylevel. Additionally, the user waspreviously restricted to specifyingmating and manufacturing overrideson single parts and pairs of parts. Theuser can now specify most mating andmanufacturing overrides on larger setsof parts, making it faster to specify andmodify those overrides, and alsoeasier to keep track of them. We addedfaceting control to speed up certainaspects of analysis and playback.

3511.090

Cloud To CAD

A. L. Ames, P. G. Xavier, C. Q. Little

Sandia is developing algorithmsthat recognize engineering shapes fromscanned data. The algorithms partitionpoints into groups that representengineering surfaces, trim and extendsurfaces, and adjust representations toachieve model closure. The algorithmswill integrate geometry from multipleviews and suggest surfaces based onengineering expectations to account forocclusions. The result of this processingis a computer-aided design (CAD) solidmodel. This representation is suitablefor a wider variety of applications thanany other geometric representation.

The benefits of generatingengineering representations of ascanned object include tremendous datacompression and object reasoning. Theshape of an object can be stored,transmitted, and reasoned about in anappropriate language (e.g., radius andheight of a cylinder), rather than in theverbose terms of thousands of points. Anobject in the field can be compared toknown designs in engineering terms.This reduces communication require-ments for battlefield reconnaissance andsurveillance.

All of our automatic engineeringalgorithms can be directly applied to theengineering representation of anacquired object in the following applica-tions: identifying targets, analyzing acompetitor’s products, designing fixtures,planning operations for demilitarizing


old ordnance, and archiving the as-builtgeometry of a stockpile component.

(1) We evaluated commercial andacademic approaches for importingscanned data into CAD as facets andcurved surfaces. Such models areuseful for visualization, but areinsufficient for many importantapplications. They exhibit insufficientor extraneous topology and aretypically expressed using inappropri-ate surface geometry. This searchleads to the requirement of producingmodels in engineering terms, withminimally complex topology andgeometry.

(2) We developed an algorithmthat connects facets into a closedboundary representation model. Themodel thus produced is sufficient forperforming Boolean operations, andfor computation of volume and massproperties. This capability provedinteresting to a commercial fundingsource.

(3) We developed routines forfitting planes, cylinders, spheres, andellipsoids to raw cloud data, forpreviously segmented data andnonsegmented data. We can extendand trim surfaces to close holes in themodel.

(4) We developed code to knittogether overlapping surfaces from 3-Drange data. We can combine surfacesfrom separate scans to form a morecomplete model.

(5) We began investigatingmethods for integrating multiple viewsinto a single solid model. We con-sidered and tested a sweep/Booleanapproach; other approaches are underdevelopment.

3511.120

Feature Reduction ofGeometric Solid Models forAnalysis Tools

P. A. Watterberg, R. G. Brown

Sandia’s goal is to facilitate task-specific simplification of solid geometricmodels for interaction with sensing,design, analysis, planning, and execu-tion tools. We will design and implementalgorithms that will streamline thedesign-to-analysis progression, therebyincreasing the capabilities of Sandia’sexisting and analysis tools underdevelopment (e.g., Archimedes, CTH,and CUBIT applications, SANDROSapplications) by eliminating complexity,which is unnecessary for specificapplications. These algorithms will alsoprovide support for the automaticcreation of simplified geometric repre-sentations that would be appropriate foruse with real-time planning and execu-tion systems, such as might be used onautonomous insectoid or vehicularrobots. Example simplifications includeelimination of purely internal featuresfrom subassemblies in an assembly-planning scenario, eliminating smallholes from an obstacle in a motion-planning scenario, and simplification orremoval of complex fillets for fixturinganalysis. We would also incorporatesome ability to simplify and refinefaceted models. Preliminary experi-ments indicate that these capabilitieswould enable our analysis tools to tackleproblems an order-of-magnitude largerthan they can currently handle andwould greatly facilitate seamlessintegration of Sandia’s many analysistools with the variety of solid-modelingpackages currently used both within theweapons complex and within U.S.industry. The ability to simplify geomet-ric models is becoming vital, as it will

become increasingly difficult for thetools used to plan manufacturing andservice operations to handle thecomplexity of the modeling systems usedto represent parts and assemblies. Thus,any design or execution code used todeal with large, complex geometries ineither the manufacturing or the roboticvehicle realms would benefit frominclusion of this technology into its core.

• Assessing specific user needs.We carried on discussions withSandians working on several projectsmaking use of geometric solid modelsto assess simplification needs.

• Prototype interactive viewing/interaction tool. We built a Motif– andGL (SGI’s graphical language)–based,mouse-driven viewing/visualizationtool that allows a user to view an ACIS(Applications of Collectively IntelligentSystems, a geometry modeling packagefrom Parametric Technologies Corpo-ration) object dynamically, frommultiple directions and magnitudes,and to interact with certain classes ofgeometric features using the mouse.We enhanced the viewing tool tohighlight specific face types and allowthe selection of a single face.

• Faceted data. We implementedstereolithography (STL) (faceted) toplanar-ACIS-body conversion andcylindrical approximation detector. Wecan now replace many cylindricalsurface approximations by an actualcylindrical surface.

We implemented several differ-ent feature-removal heuristics. Weremoved holes less than a specifiedsize, slots and voids in planar surfaces,and chamfers and fillets. We appliedthese heuristics to several sampleobjects yielding mostly modest results.Some objects yielded dramatic results.Continued refinement of the algo-rithms should yield satisfactory resultson most objects.


3511.110

Ergonomics in Life-CycleAssembly Processes

T. L. Calton, T. S. Gladwell, J. C. Trinkle,R. J. Anderson, R. R. Peters

To meet the design-to-costs ofSandia’s operation/sustainment, weneed to identify, develop, and integrateimproved, affordable manufacturingtechnologies that must allow for designand assembly at a lower cost withgreater flexibility. All automatedassembly-planning software toolsassume that the individual componentsfly into their assembly positions; inreality they have to be moved withhuman hands rather than mechanicaldevices. Automatic assembly sequencingand visualization tools are valuable indetermining the best (dis)assemblysequences/plans for weapons and othermilitary and industrial system compo-nents and subassemblies, but withoutHuman Factors and Figure Models(HFFMs) it is difficult to evaluate orvisualize human interaction. HFFMsallow engineers to verify that mainte-nance is possible and see ways to makethe design even better.

The goals of this project are indirect alignment with Sandia’s Applica-tions of Collectively Intelligent Systems(ACIS) business focus; war-fightingoperations, both military logistics andautomated ship functions, are areas ofthis project that can have significantimpacts in reducing physical mock-upsrequired for training personnel inmaintenance operations, reducing depotrepair and logistical footprints, andproviding repair-on-demand services.Already a cooperative research and

development program initiated by theU.S. Army’s Aviation Applied Technol-ogy Directorate (AATD), SikorskyAircraft Corporation conducted a nine-month study and identified our assemblyplanner as a technology that could helpovercome critical barriers that arepreventing airframes from being trulyaffordable. They concluded that toaccurately verify assemblability/maintainability, it is necessary toinclude HFFMs.

Our first-year work included (1)surveying human modeling software,surveying the research in humanfactors and manufacturing, surveyinghuman factors that are of interest toboth the public and private communi-ties, and selecting a commerciallyavailable human modeling softwarepackage, (2) integrating the humanfigure model with Sandia’s collision-detection software system, (3) defininghand grasps for tools in theArchimedes Tool Library, (4) develop-ing a routine to compute sweepvolumes of the hand and tool(s),(5) implementing inverse kinematicroutines for the human arm, (6)developing a motion planner for tool/hand and arm, and (7) implementingthe first prototype. We focused on thegeometric and kinematic representa-tions of humans.

(1) Surveys. We completed asurvey of commercially availablehuman modeling software packagesand identified two appropriate candi-dates: Jack by Transom and ErgoManby Deneb. The direct integration of anoncommercial model increases themarketability of the resulting productby reducing the cost to a user. Thisactivity will occur next year.

Each of these two commercialhuman figure models offers variouslevels of sophistication and features.Jack is differentiated from ErgoMan bya number of features. (a) Staturemodels: The models in Jack have muchgreater sophistication allowing scalingin stature and corpulence, withappropriate models of children as wellas adults. They also maintain extensivedemographics information for differentcultures. (b) Sophistication of model:Jack is a 17-degree-of-freedom (DOF)torso model. (c) Behavioral models:Jack utilizes a PATNET (ParallelTransition Network) to define behaviorchanges. Jack can implement behav-iors such as maintain balance whileexecuting a given task, take a stepforward if needed, keep one hand on atable while reaching, or keep his eyeson a target object at all times. ErgoManhas no such capability. Although theJack model is anthropomorphicallymore appealing, we are currentlydeveloping algorithms based on theErgoMan model and will use Jack nextyear.

We assimilated an extensivecollection of research and develop-ment documents and Web sitesidentifying current trends in humanfigure modeling and on human factors.They range from scientific applicationsin ergonomics to gait analysis ofathletes to physical rehabilitation.

(2) We selected Sandia’s colli-sion-detection software package,C-Space Toolkit (CSTK), for integrationwith both ErgoMan and Jack. CSTKprovides a library that makes it easierto program motion-planning, simula-tion, robotics, and virtual reality codesusing the configuration space abstrac-


tion. We integrated the CSTK withDeneb’s Telegrip package.

(3) We defined hand grasps fortools in the Archimedes Tool Library.For each of those tools we defined adiscrete set of standard positions,torques, and tool-offsets. The impor-tance of establishing a variety of handgrasps for each tool is that a widerclass of humans may be assessed, thusoffering greater flexibility in thesystem.

(4) For each of the hand graspsdefined, we predefined an upperbound on the space required to applyit; such volume represents a sufficientcondition for tool applications. Nextyear we will implement a more flexibleapproach using the motion planner tofind approach and removal paths fortool/hand and arm wielder.

(5) We implemented a 7-DOFinverse kinematic numerical solutionand a straight-line motion planner tocompute the arm joint angles that arenecessary to move the tool and handalong a desired path.

(6) We developed a motionplanner for tool/hand and arm. Herewe planned to integrate SANDROS PathPlanner and the SMART motion-planning algorithms. We canceled thisactivity because of scheduling con-flicts.

(7) We began the initial phases ofintegration with the ArchimedesAssembly Planner. Archimedesgenerated a script containing thesequence of (dis)assembly, toolselection, and trajectories of motions.We then used this script within IGRIP’ssimulation package to demonstrate thefeasibility of the operations.

3511.130

System Surety Life-CycleEngineering

R. A. Sarfaty, W. F. Young, R. L.Hutchinson, S. V. Spires, G. E. Rivord, S.Y. Goldsmith

System surety modeling currentlylacks formalized overarching methodsthat scrutinize the engineering lifecyclecommencing with abstraction andrequirements-gathering. Object-orientedmethodologies evolved to yield, interalia, encapsulation, polymorphism, andinheritance. However, surety’s securityand availability balance are obviated bythe object-oriented Unified Method (UM)modeling technique dynamic model,particularly user authentication,confidentiality, and nonrepudiation. UMalso lacks cost/risk information,assessed through consequence model-ing, thereby failing to address the systemas a whole.

This research will expand each ofUM’s three models (object, dynamic, andfunctional) under systems engineeringlifecycle, to include surety’s components(reliability, user-authentication, dataintegrity, confidentiality, nonrepudi-ation) and incorporate the consequencemodel yielding bi-directional temporalcost analyses complemented withstochastic probabilistic risk assessment(PRA), or similar techniques.

The meta-modeling techniques(enhanced UM) would include object–based technology to ensure validationand cross-referencing among the fourmodels. Surety objects would gaincognition through a dynamic knowledge-base such as secure network segments,encryption algorithms, and vulnerabilityassessments resulting from natural andanthropogenic threats. Most knowledge-

base repositories are static, requiringtriggers for updates; conversely, suretyobjects would augment their knowledgedynamically (emergent behavior) basedon empirical outcomes, hence serving asthe filters to coalesce surety elementsinto the system’s lifecycle.

Subsequently a tool developmenteffort would deliver a modeling enginewith graphical interfaces accessible to asystems/surety engineer. The engine thattransparently performs system constraintvalidations to the user facilitates themodeling process. This allows forsystems surety modeling without the UMexpert knowledge while yielding robustand valid system designs throughout thelifecycle.

• We conducted a fairly extensiveinvestigation into the meta-modelinglanguage and the three models of theUnified Modeling Language (UML).

• We established interdependen-cies among the object, dynamic, andconsequence models.

• We formulated the informationsurety modeling methodology byselecting an example problem (i.e., theinfrastructure surety problem).

• We began adding object modelelements based on the UML to supportthe augmented methodology.

• We established a use-casescenario that will test the interdepen-dencies of various critical infrastruc-tures from a critical node perspectiveand assess the impact of each efferentand afferent link to the object model.The underlying meta-language is underdevelopment and uses both Booleanlogic and predicate calculus. Wecreated several nominal models to testthe impact of classes on critical nodes(e.g., energy, capital, information) anddefined the first-order rules to conductforward transformations.










INFORMATION

SYSTEMS

Information technology provides support tomission-critical Sandia activities. Information Systemsresearch ensures that Sandia engineers and scientistscan reduce time and costs associated with stockpilestewardship and other, related goals. Informationsurety is important to certifying critical infrastructuresand mitigating emerging threats. Desirable projects include developing secure,high-speed computer networks and location-insensitive computing, converting data to information,and developing the science of information. Sandia is developing a technology to manageambiguous data, called mission surety, that is criticalfor large-scale, real-time information systems. Militaryand defense applications must deal with ambiguousinformation and/or data with errors, creating theneed for a technology that monitors decisions basedon incomplete or inconsistent data. This conceptallows researchers to design systems that compensatefor erroneous decisions by enabling the algorithm tobacktrack and recover when errors are detected.Before, systems would ignore the errors or eventuallythrow out the results and start over when it becameclear the system had made a big mistake.�� Mission surety technology allows the softwareto detect the wrong turn as soon as possible, figureout how far back the decision-making process has togo, return to that point, then continue down thecorrect path. Benefits include greatly reducing developmentcosts for certain information-intensive defensesystems. In collaboration with the University of NewMexico, Sandia is adapting this technology to makeless expensive, more accurate models of roads andother large components of the nation’s infrastructures.





3512.160

Content–Based Search ofGeometric Databases

P. G. Xavier, L. Meirans, T. R. Henry, L.P. Ray, Y. K. Hwang, R. A. Lafarge

Unlike textual or numerical data,geometry currently cannot be indexed orsearched. Consequently, users ofgeometric data, such as designers, are ata considerable disadvantage whenattempting to benefit from past experi-ence. The impact of textual searchsystems such as SMART and Alta Vistahint at the potential if geometric datawere to be successfully indexed andmade available online. Sandia isdeveloping algorithms and a prototypesystem for efficiently searching data-bases of 3-D geometric data by content.

Our main achievement is aprototype system for searching data-bases of geometric models such asAutoCAD. In addition to use in design,the underlying technology is suitable forautonomously identifying and estimatingthe pose of singulated objects that havebeen scanned to produce a renderable3-D model. In addition, we completedsoftware for automatically recognizingand characterizing holes and pockets incomputer-assisted design (CAD) models.However, we finished this work too lateto integrate it into our index-buildingcode and interactive query system.

Our main achievement this yearwas a prototype system for searchingdatabases of geometric models, suchas AutoCAD. Mode of use is simple:The user loads a 3-D query object intothe system, selects a view, and thesystem searches for objects in thedatabase most similar in overall shape.Objects may be searched for based onany view, but some views may benondistinguishing. While geometricmodels can be added to the databaseindex incrementally, speed and storagespace can be optimized in a globalpost-process. Models can be addedafter this post-processing, but if thedomain sample is not adequate, speedand accuracy may be affected. In

addition to use in design, the underly-ing technology is suitable for autono-mously identifying and estimating thepose of singulated objects that havebeen scanned to produce a renderable3-D model.

We tested the system with adatabase of over 200 CAD models, andit performed accurately and intuitively.Preliminary testing with 32 models andusing randomly selected views yieldedover 99% accuracy. We will includequantitative results based on thelarger data set in the final report.

We also completed software forautomatically recognizing and charac-terizing holes and pockets in CADmodels, but we finished this work toolate to integrate it into our index-building code and interactive querysystem.

Publications

Other

Xavier, P. G., L. P. Ray, T. R. Henry, R. A.Lafarge, and L. Meirans. 1998. “Con-tent–Based Search on a Database ofGeometric Models: Identifying Objectsof Similar Shape.” Sandia TechnicalReport SAND98-2684 (November).Sandia National Laboratories, Albu-querque, NM.

3512.190

Mission Surety for Large-Scale Real-Time InformationSystems

S. J. Bespalko, H. L. Dison

This project will develop a newcapability, termed mission surety, thatwill enable the designers of large-scale,real-time systems to guarantee thecorrectness of results. Complexity of asystem, and thus the propensity forerror, is best characterized by thenumber of states the system canencounter. In general, the number ofstates grows exponentially as datasources are added. It is unlikely thatcurrent ad hoc methods of developing

systems will be able to handle thisincreasing complexity.

Two technologies will provide thebasis for establishing mission surety.Over the past two years Sandiaanalyzed the problematical modules inan operational defense system anddeveloped extensions to existing formallanguage techniques. These newmethods provide a comprehensive andcompact method for specifying, andsubsequently automatically generating,error-free implementations.

We performed an analysis onICADS (a Sandia-developedgroundstation application) thatconcluded that the source of mosterrors in the development processresulted from the inadequacy of thedesign methodology.

We completed the second ofthree activities to demonstrate formallanguages application. The algorithm isa new method of deducing whichtriggers are associated with a singleevent. This new algorithm makes noheuristic steps and is completelydefined in terms of nonlinear optimiza-tion steps and formal language.

The project resulted in a newmission-critical algorithm for adeployed war-fighting system devel-oped at Sandia. The algorithm beattwo other algorithms based onheuristics, and also beat the currentalgorithm by making nearly two-orders-of-magnitude fewer errors. Thisdemonstrates in no uncertain termsthe power of rigorous design inmission-critical software.

Publications

Refereed

Bespalko, S. J., D. L. Sulsky, M. M.Wyman, and H. L. Dison. 1998. “ANonlinear Correction for GPS Data.”Federal Research Record, accepted.

Bespalko, S. J., D. L. Sulsky, M. M.Wyman, and H. L. Dison. 1998. “ANonlinear Correction for GPS Data.”Proc. 1999 Winter Mtg. of the Transpor-tation Res. Board 1 (Washington, DC, 10January 1999).


3512.170

Integrated ServiceProvisioning in an “IPv6 overATM” Research Network

H. Y. Chen, D. W. Palmer, P. J.Robertson, J. A. Friesen, R. P. Tsang, J.M. Brandt

During the past few years theworldwide Internet has grown at aphenomenal rate, which has spurred theproposal of innovative network tech-nologies to support the fast, efficient,and low-latency transport of a widespectrum of multimedia traffic types.Existing network infrastructures havebeen plagued by their inability toprovide for real-time application traffic,as well as their general lack of resourcesand resilience to congestion. This workaddresses these issues by implementinga prototype high-speed network infra-structure consisting of Internet ProtocolVersion 6 (IPv6) on top of an asynchro-nous transfer mode (ATM) transportmedium. Since ATM is connection-oriented while IP uses a connectionlessparadigm, the efficient integration ofIPv6 over ATM is especially challengingand has generated much interest in theresearch community. Sandia will, incollaboration with an industry partner,implement IPv6 over ATM using aunique approach that integrates IP overfast ATM hardware while still preservingIP’s connectionless paradigm. We willachieve this by replacing ATM’s controlsoftware with IP’s routing code and bycaching IP’s forwarding decisions inATM’s virtual path identifier/virtualcircuit identifier (VPI/VCI) translationtables. We will also develop prototypevirtual reality (VR) and distributed-parallel-computing applications toexercise the real-time capability of ourIPv6 over ATM network.

(1) The integrated service networktest-bed. While IPv6 is defined toaddress the exhaustion and routing-table explosion issues caused by theexponential growth of today’s globalInternet, the sheer size of the IPv4Internet complicates its transitionprocess to IPv6. Like most vendors,

our research partner, Ipsilon, alsochose to take the path of least resis-tance and embrace the intermediatesolution, the Classless Inter DomainRouting (CIDR), which offers tempo-rary relief to these symptoms. Addi-tionally, switched Gigabit Ethernet isthe new technology trend for localarea networks (LANs), which hasinfluenced Ipsilon’s business decisionon future product directions. Accord-ingly, we also changed our researchdirection to one that implementsDifferentiated Services (DiffServ) onIPv4 networks that support CIDR. Thefundamental elements of DiffServinclude per-hop forwarding behaviors,packet classification functions, andtraffic conditioning (traffic metering,marking, shaping, and policing). Webuilt a test-bed that consists of fivePC–based nodes with kernel modifiedto support the DiffServ functions. Weplan to become a member of the ESnetDiffServ workshop to gain globalexperience.

(2) The mission-critical visualiza-tion applications. Because of thegeographical distribution of its twosites, scientists and engineers atSandia are especially sensitive toperformance issues in distant comput-ing. In particular, the ability to provideefficient visualization of scientific dataover local- and wide-area networks(LANs/WANs) is of major concern. Inthe past year, we characterized thetraffic pattern of two mission-criticalvisualization applications at Sandia,the client-server–based Ensight, andthe remote-x–based CTH code. Wemodeled the applications traffic usingmeasured statistics. These models cangenerate traffic for simulation andexperimental studies to understandresource allocation mechanisms andthe performance metrics in terms oftheir ability to deliver the contractedquality of services (QoS).

(3) The digital video transportsystem. Several experimental studies atSandia strive to improve the perfor-mance of remote visualization overWAN by taking advantage of theremote graphic server’s hardware

speed, and by eliminating cumulativeround-trip delays caused by the X andGL (SGI’s graphical language) com-mands exchanged during interactivesessions. These experiments use ascan converter that takes the analogsignal of the server’s display andconverts it to NTSC (National Televi-sion System Committee) frames. TheNTSC frames are then digitized,compressed, and streamed over thenetwork using an MPEG2/JPEG(Moving Picture Expert Group2/JointPicture Expert Group) encoder. At thereceiving end, a decoder reverses theprocess and sends the recoveredanalog signal to the monitor of adesktop. Meanwhile, a software utilityis used to transfer the control ofmouse and keyboard from the serverto the desktop, thereby allowing theremote user to manipulate the server’sdisplay as if it were local.

While video compressionpreserves the precious wide-areabandwidth, it degrades video qualitybecause of the lossy JPEG/MPEGcompression and the conversion fromthe display (1280x1024) to NTSC(~ 640x480) signal. Therefore, we willbuild a high-resolution digital videotransport system, without compres-sion, for large campus environmentswhere bandwidth is plentiful. Thissystem takes the high-resolution(1280x1024x24) digital video signaldirectly from the graphics server’sframe buffer, via a parallel digitalinterface (DVP2), and then directmemory accesses (DMAs) it to aGigabit Ethernet or ATM interface overthe system’s PCI (peripheral compo-nent interconnect) bus. The systemwill then distribute the digital videosignal to remote desktops aroundcampus. We can adjust its bandwidthrequirements by varying the transmis-sion frame rates, which can rangebetween 11 and 30 fps. We finished thedesign phase with complete schematicdrawings.

These two video applications willprovide real-time, constant, andvariable-bit-rate traffic streams for ourDiffServ study.


Publications

Other

Chen, H. Y. 1997. “A User’s Perspectiveon the IP over ATM Approaches.”Paper presented to the 22nd IEEE LocalComputer Network, Expert PanelSession 2 (Invited panelist), Minneapo-lis, MN, 5 November.

Chen, H. Y. 1998. “Data Flow Modelingof ASCI Remote Visualization.” Presen-tation to the JOWOG Meeting (Invited),Livermore, CA, 18 June.

3512.180

Virtual Desktop Engineeringwith Integrated MultimediaData

J. A. Friesen, J. Schwegel, J. N. Jortner

The growth of the Internet hasspurred the development of innovativetechnologies that support the fusion of awide spectrum of multimedia data types.Those technologies have made itpossible to provide an environment inwhich engineers can design, prototype,and test components in a virtual spacewhile integrating actual data into theprocess.

Sandia will insert multimediastreams such as video into a desktopvirtual reality (VR) environment. Wewill store compressed audio, video,animation, scientific visualization, andtext streams in a distributed databaseand deliver it in real time over thenetwork to desktop computers. Usingleading-edge World Wide Web (WWW)technology such as Java and VirtualReality Modeling Language (VRML), wewill build an integrated VR environmentunlike any currently available on high-end visualization servers.

For example, an engineer usingProEngineer to design a mechanical partcould call up similar products from amultimedia part database that displays

part behavior from a 3-D perspective. Inaddition, audio/video clips of engineer-ing advisors, test data, and computersimulations could be displayed interac-tively. After designing the part, theengineer can virtually manufacture thepart to predict actual part performance.

Engineers can quickly evaluate thequality of a design in an interactiveenvironment. Using collaboration tools,they will be able to virtually design,manufacture, and test a part beforeresorting to stereolithography (STL).That will result in significant reductionof cycle time and cost. In addition, theycan archive the design process inmultimedia form for future use.

Sandia has made substantialinvestments in a number of technolo-gies to support concurrent engineeringand integrated manufacturing. Theappropriate integration of thesecomponent technologies is essential torealize the full potential of theseinvestments. This project will integratea number of leading-edge technologiesinto a collaborative environment tofacilitate rapid product realization.

Specifically, we designed andcreated an environment and facilitywhere engineers can design, proto-type, and test components in a virtualspace, and analysts can explore theresults of their large-scale simulations.The environment is composed of thelatest interface and display technologyand is backed up by the highest-performance networking and storagesystems available.

Technologies brought togetherto implement this design facilityinclude graphical supercomputers,advanced visual projection systems,leading-edge audio/video switchingsystems, and state-of-the-art interac-tive modeling and analysis software.Using this collaborative environment,we demonstrated the following designand analysis functions:

(1) Interactive viewing andmanipulation of scientific data in a 3-Denvironment.

(2) Application of kinematicmotion data and telemetry data tosimulations.

(3) Integration of flight-test datawith visualization packages to producephysically correct simulations.

(4) Animation of mechanicalassemblies for training, assembly, andarchive purposes.

(5) Conversion of solid-modelassemblies into Web-friendly formatsfor presentation purposes.

(6) Delivery of simulation resultsover the network to customers.

(7) Archival of graphical resultsin multimedia databases for future use.

Based on experiences with ourpilot project, we decided not to wrapour applications. At the start of thisproject, critical software methods usedfor wrapping applications were in theirfledgling state and therefore notintegrated into this project. Thisapproach should be reevaluated oncethe software methods become moredeveloped and stable. The decision toimplement a collaborative co-locatedenvironment rather than a distributedenvironment, shifting focus fromindividual to team environments, wasalso based on lessons learned with ourpilot project. Engineers and analystsare more comfortable using localcomputers to handle their day-to-daytasks and needed more assistanceattacking larger computationalproblems. We deemed high-resolution,large-scale group viewing facilitiesmore critical to customers’ operationalneeds than individual desktop solu-tions.

The integration of real data withvisualization provides valuable insightinto the behavior of test situations thatcannot be witnessed directly. Usingthis collaborative environment,Sandians will improve their engineer-ing process, thus facilitating morerapid product realization.


3512.220

Scaled ATM End-to-EndEncryption

L. G. Pierson, P. J. Robertson, T. D.Tarman, L. B. Dean, E. L. Witzke

This project will position Sandiato influence and accelerate the deploy-ment of scalable, variable-bit-rate (VBR)asynchronous transfer mode (ATM)encryption equipment needed to satisfyDOE/ASCI (Accelerated StrategicComputing Initiative) requirements forcommunication security. The Microelec-tronics Center of North Carolina (MCNC)“Attila” prototype ATM end-to-endencryptor is the fastest known, operatingat 622 Mb/s. Sandia’s Scalable ATMEncryptor Prototype is the secondfastest, operating at 155 Mb/s. The NSA(National Security Agency) “Milkbush”prototype encryptor is the third fastest,operating at about 100 Mb/s. NSA’sefforts have evolved into plans to makecommercially available ATM end-to-endencryptors that operate at up to 0.6Gb/s, yet little work is ongoing to deliverATM encryptors for the higher data rates(2 to 10 Gb/s) expected to soon berequired to meet ASCI objectives.

This research integrated innova-tive methods of key management, cryptosynchronization, and key agility whilescaling encryption speed. We identifiedencryption modes of operation that arescalable, yet interoperable with dissimi-larly scaled implementations, anddeveloped prototype encryptor designs.We simulated and/or prototyped majorportions of these designs for perfor-mance assessment. We showed viabilityof these methods for encryption of ATMcell payloads at the SONET (Synchro-nous Optical Network) OC-192 data rate(10 Gb/s), and for operation at OC-48rates (2.5 Gb/s).

We established collaborationwith academia, NSA, GTE, Motorola,Secant Networking, Fore Systems, and

elements of the telecommunicationsindustry. We co-developed analgorithm-agile and key-agile architec-ture with NSA/R22. As a result ofSandia’s participation in the SecurityWorking Group of the ATM Forum, ascalable and interoperable encryptionmethod was incorporated into theATM Forum’s Security Specificationversion 1.0. We identified authentica-tion mechanisms for key managementimplementation. We selected encryp-tion mechanisms for prototypeimplementation at high speeds. Wedeveloped and simulated a 16-stagepipelined implementation of the DataEncryption Standard (DES). Thesimulations show that this design willoperate at 1.3 Gb/s in reconfigurablelogic, and implementation in the formof an Applications of CollectivelyIntelligent Systems (ASIC) is expectedto yield over 5 Gb/s in complementarymetallic oxide semiconductor (CMOS)or 40 Gb/s in GaAs. We designed anelectronic circuit board containingeleven high-density programmablelogic devices and fabricated it forprototype implementation of theencryption mechanisms. This circuitboard won the 1998 VeriBest SuperiorSystems Award for the most unusualcircuit board design.

This effort integrated innovativemethods of key management, cryptosynchronization, and key agility whilescaling encryption speed. We identifiedencryption modes of operation, whichare scalable and yet interoperable withdissimilarly scaled implementations,and developed prototype encryptordesigns. We simulated major portionsof these designs and/or prototypedthem for performance assessment. Weshowed viability of these methods forencryption of ATM cell payloads at theSONET OC-192 data rate (10 Gb/s), andfor operation at OC-48 rates (2.5 Gb/s).

This effort positioned Sandia toinfluence and accelerate the deploy-

ment of scalable, VBR ATM encryptionequipment needed to satisfy DOE/ASCIrequirements for communicationsecurity. Through collaborations withNSA, this research demonstrated theviability of these techniques for scalingencryption speed. Because of theexpertise developed in this area,project personnel have been invited toparticipate in the ongoing designreviews for the development of theproduction GTE 10 Gb/s encryptor tofurther ensure that the deliveredencryption equipment will meet DOEneeds.

Publications

Refereed

Tarman, T. D., R. L. Hutchinson, L. G.Pierson, P. E. Scholander, and E. L.Witzke. 1998. “Algorithm-Agile Encryp-tion in ATM Networks.” IEEE Computer31 (9) (September): 57–64.

3512.250

Ten-to-One-Hundred-Gigabit/Second Network EnablingR&D

L. B. Dean, M. A. Ngujo, T. D. Tarman, L.G. Pierson, P. L. Campbell, R. L.Hutchinson, P. J. Robertson, J. G. Peña

The next major performanceplateau for high-speed, long-haulnetworks is at 10 Gbps (OC-192). Datavisualization, high-performance networkstorage, and distributed massivelyparallel processing (MPP) all demandthese (and higher) communicationrates. Previous research and AcceleratedStrategic Computing Initiative (ASCI)needs show that MPP-to-MPP distributedprocessing applications and MPP-to-Network File Store applications alreadyrequire single-conversation communica-tion rates in the range of 10 to 100 Gbps.


MPP-to-visualization station applicationsare ready now to utilize communicationrates of 1 to 10 Gbps. The ASCI roadmapspecifies 100 Gbps interconnects for 100-teraflop computers.

We conducted theoretical exami-nations, based on Lambda calculus, ofthe foundations of MP computing andinterconnects to create models ofcomputing communications traffic. Weare considering these models forimplementation as traffic sources forcommunication system models. TheLambda calculus work seeded otherproposals and new research collabora-tions.

Finally, we developed a scalableimplementation of the Internet Protocol(IP), including IP switching andmultiprotocol over ATM (MPOA), amethod for providing cut-through routingfor IP datagrams. We also describedalternative mechanisms for providingapplication data services in excess of 10Gbps, including emerging operating-system bypass technologies, like thevirtual interface architecture (VIA) andscheduled transfer (ST) protocols. Themodel led to several new and refinedproject internal milestones.

We completed an internal whitepaper on the architecture design,development, and technology selec-tion rationale for this research. Itdescribes a high-level architecturalmodel for our effort that shows how avariety of protocols and componentscan fit together to provide the desired10–100 Gbps research results we seek.At the lowest level of this model arethe physical layer technologies,including the SONET and wave divisionmultiplexing (WDM) technologies.Above the physical layer, we describedswitching and interface technologies,including ATM switching, UTOPIA, andAAL mechanisms. Finally, we investi-

gated methods for the scalableimplementation of the IP, including IPswitching and MPOA. We alsodescribed alternative mechanisms forproviding application data services inexcess of 10 Gbps, including emergingoperating-system (OS) bypass tech-nologies, especially the VIA and STprotocols. As a direct result of themodel architecture work, we devel-oped and refined several new projectinternal milestones.

We completed a detailed projectplan and an initial literature survey,both of which are now living docu-ments to keep up with the rapidchanges in the field. Based on these,we decided to pursue doped opticalfiber amplifiers rather than supercon-ducting Josephson junctions (SJJ). Theerbium-doped, and the related emerg-ing neodymium and praseodymiumrare-earth (RE)-doped, optical fiberamplifier technologies are mature andwill likely be a mainstay of future long-haul communications. SJJs are still tooimmature for our use and have theconsiderable operational overhead ofneeding cooling.

We completed the implementa-tion of the PLD-11 flexible prototypingboard, with which we will evaluatemethods of processing communica-tions protocol functions in parallel athigh speed. We selected and pur-chased our major network simulationtool, OPNET Modeler, and completedstaff training on it. We developedcommunication system models incollaboration with the Nanosat team.We began the detailed study of WDMand of optical computing (OC).Emerging evidence indicates that fullOC will most likely drop out as a viabletechnology for our work, being tooimmature for use in our time frame.However, we will be able to use some

emerging, purely optical processing fora few critical communications func-tions.

We completed a number of viabledesigns for scalable UTOPIA interfaces,including an innovative separation ofheader from payload in processingstreams yielding higher-throughput 64-and 128-bit-wide data paths. This led tonew designs that scale UTOPIA acrossthe whole range from 1 to 424 bits (fullcell) width. We completed firstbenchmark feasibility designs forframing ATM cells into SONET and forinterfacing SONET framers to ATMdevices using UTOPIA. We will test andevaluate these results on the PLD-11board.

We initiated a study of the OSbypasses: the Virtual Interface Archi-tecture (VIA), Scheduled Transfer, theData Link Providers Interface, and theAdvanced Graphics Port protocols. Wecompleted initial investigation of thescalability of the ATM adaptation layerand the IP. We initiated a study of theInverse Multiplexing of ATM, to beused in matching rates to processesand available circuits.

We completed theoretical studieson the feasibility of developingLambda calculus–based models forgenerating computer traffic statisticsand mapping MP computations toprocessors. We are considering thesemodels for implementation as trafficsources for communication systemmodels. We filed a Sandia TechnicalAdvance on a portion of this work. Itappears to allow great advances inmapping computer applications to MPand distributed processors, includingad hoc collections of processors. ThisLambda calculus work seeded otherproposals and new research collabora-tions.


3512.230

Network Surety Modeling forWireless ATM Networks

B. P. Van Leeuwen, P. E. Sholander, L. F.Tolendino, L. G. Martinez, Jr., B. A. Mah,J. Espinoza

In general, there are four types ofnetwork elements: fixed systems that aretracked by the routing protocol, fixedsystems that participate in the routingprotocol, mobile systems that aretracked by the routing protocol, andmobile systems that participate in therouting protocol. The fourth type,movable asynchronous transfer mode(ATM) switches, is a research focus ofthis project.

There are two areas of interest.The first area is integrating mobile ATMswitches into a mainly fixed infrastruc-ture that uses a link-state routingprotocol such as the ATM Forum’sPrivate Network–Network Interface(PNNI) protocol. The second area is adhoc network topologies wherein mostnetwork elements have some switchingfunctionality. Standard link-state routingprotocols may not work well in dynamic,ad hoc networks. This mobile switchwork addressing the problem of mobilitymanagement and routing is important tovarious government and commercialusers, such as DOE, DoD, and Boeing.

Proposed wireless asynchronoustransfer mode (WATM) systems presentseveral interesting problems. The firstproblem is quality of service (QoS). ATMis optimized for optical fiber channelsthat have both low error rates and lowlatency. In contrast, wireless channelsmay have much higher latency and/orerror rates. Mobility introduces other

QoS impairments. For example,handoffs between wireless-cells mayrequire ATM-cell buffering during thenetwork path rearrangement. Thisbuffering may increase the cell loss rate.

This research investigated variousapproaches and protocols used forrouting information through dynamicnetwork topologies or networks thathave mobile nodes. We focused onissues that mostly reside in the networkand data link layers of the OSI (opensystem interconnection) networkarchitecture model. We addressednetwork organization, link scheduling,and routing in the protocols. One knowneffect is that transmission controlprotocol (TCP) will interpret anyincreased ATM-cell loss as congestion.This may significantly reduce the TCPthroughput..

We developed extensions forATM’s PNNI protocol that wouldsupport mobility. We identified anumber of specific mobility impair-ment issues and proposed extensionsfor these impairments.

We identified a new networkimpairment for proposed WATMsystems—namely, the effects of usermobility on usage parameter control(UPC)—that is not present in existingATM networks and cellular networks.

We extended the outside nodalhierarchy list (ONHL) procedures.These extensions allow multiplemobile networks to form either an adhoc network or an extension of a fixedPNNI infrastructure.

We examined methods of mobilecommunications with an emphasis onmobile computing and wirelesscommunications. Many of the ad-vances in communications involve the

use of Internet Protocol (IP), ATM, andad hoc network protocols. Recently wedirected our focus on advancingcommunication technology in the areaof mobile wireless networks. Welooked at various protocols used inmobile communications and a numberof extensions to existing protocols,desirable protocol characteristics andevaluation criteria, and severalnetwork simulation tools that may beused to evaluate network protocols.

Publications

Refereed

Sholander, P., L. Martinez, L.Tolendino, and B. Mah. 1998. “TheEffects of User Mobility on UsageParameter Control in Wireless ATMSystems.” Proc. 1998 IEEE Internat. Perf.Computing and Commun. Conf., ac-cepted.

Other

Sholander, P., L. Martinez, and L.Tolendino. 1997. “PNNI RoutingSupport for Ad Hoc Mobile Networking:A Flat Architecture.” Paper presentedto the ATM Forum, Singapore, Malay-sia, 29 November.

Sholander, P., L. Martinez, and L.Tolendino. 1998. “PNNI RoutingSupport for Ad Hoc Mobile Networking:The Multilevel Case.” Paper presentedto the ATM Forum, Anaheim, CA, 8February.

Sholander, P., L. Martinez, and L.Tolendino. 1997. “The Effects of MobileATM Switches on PNNI Peer GroupOperation.” Paper presented to theATM Forum, Chicago, IL, 28 April.


3512.280

Algorithm–Based FaultTolerance on HeterogeneousMassively Parallel Computers

P. D. Hough, M. M. Johnson, C. H. Tong

Sandia will do research anddevelopment of fault-tolerance strategies(e.g., in redundancy design, faultdetection, fault recovery) and theimplementation of a fault-tolerantsoftware environment for massivelyparallel (MP) heterogeneous systemssuch as Sandia’s Computational Plant(Cplant). Such systems are morevulnerable to failures than homoge-neous systems, like Sandia’s Tflopmachine, due to the diverse subsystemand network architectures, the need formultiple operating-system (OS) support,and the decentralized computing andstorage platforms. These unique featuresmandate a fundamental change in fault-tolerance strategies. We will develop analgorithm-dependent fault-tolerancemethodology based on a combination ofdisk–based and diskless checkpointing.This hybrid approach offers lowoverhead and allows fine-tuning forefficient performance of individualapplications. We will encapsulate thetechniques in a Java–based object-oriented framework and apply it to anumber of Sandia applications, includ-ing linear system solvers in AZTEC,numerical optimization methods inOPT++, and enterprise simulations

(IDES [Infrastructure for DistributedEnterprise Simulations]). In addition, wewill develop failure models to assess theeffectiveness of and to suggest refine-ments for the fault-tolerance strategies.The effort will enhance the robustness ofSandia’s distributed computing applica-tions, especially on heterogeneousplatforms such as the Cplant. It will havean immediate impact on problems inenterprise modeling, optimal design,and DOE2000 projects. Moreover, thefault-recovery techniques to be devel-oped for the software environment willinclude strategies for process migration,processor reconfiguration, and reclama-tion, thus contributing to the advance-ment of location-insensitive heteroge-neous computing technology at Sandia.

We compiled a list of faultscenarios and determined which ofthose are most likely to occur. Devel-opment focuses on covering the morecommon failures while allowing theflexibility to incorporate others. Wealso determined fault scenariosparticular to Cplant.

We designed a framework forimplementing fault tolerance. Thebasic components include a faultdetector, a fault handler, and amachine description. We will incorpo-rate basic tools for recovery in alibrary accessible by the application.

We are currently using Pentium–based PC clusters for development.These clusters have message-passinginterface (MPI) and Java available for

use. Cplant clusters of DEC Alphas arenow available for use and will beincorporated.

We designed fault-detectionschemes for two common machinetopologies. These are simple algo-rithms that are incorporated into ahierarchical structure to allow forscalability. We implemented theseschemes in Java and completedincorporation into the hierarchy. Inaddition to detecting faults, this codeallows resources to be reclaimed if thefailure is intermittent.

We prototyped a fault-tolerantversion of an unconstrained paralleldirect search optimization algorithm.This is based on a master-slaveformulation, and the algorithm itselfcan tolerate some loss of information.We currently use checkpointing tohandle the failure of the master, but weare investigating alternate techniques.

We implemented a fault-tolerantversion of a statistical sampling toolintended for use in the validation andverification of large AcceleratedStrategic Computing Initiative (ASCI)codes. The implementation is similarto that for the optimization algorithmexcept that all information is recov-ered in the event of a failure.

We are collaborating withresearchers at the University ofFlorida. They are developing simula-tion tools useful for our study ofvarious fault scenarios and evaluationof fault-tolerance tools.


3512.260

High-PerformanceCommodity Interconnects forClustered Scientific andEngineering Computing

L. Stans, T. D. Tarman, T. C. Hu, R. C.Armstrong, P. S. Wyckoff, H. Y. Chen

The Computational Plant (Cplant)runs distributed parallel applications ona large cluster of commodity PCs.Because properly load-balanceddistributed parallel applications tend tosend messages synchronously, minimalblocking is as crucial a requirement ashigh bandwidth and low latency.Therefore, the following factors areimportant network design consider-ations: (1) the selection of an optimalcommodity interconnect networktechnology and topology to provide bothhigh bandwidth and congestion control,and (2) the development of an efficientlocal-area communication layer tominimize per-packet processing latencyin compute and input/output (I/O)nodes.

The goal of this project is todevelop and demonstrate a designmethodology for constructing high-performance interconnects using high-bandwidth, low-latency, local-areanetwork (LAN) technologies such asMyrinet, asynchronous transfer mode(ATM), switched Gigabit Ethernet, andthe emerging operating-system (OS)bypass Virtual Interface Architecture(VIA). An important element of theresearch is the pursuit of an emergingcommunication model that decouplesI/O support from the OS and allowsindividual applications to directlycontrol their own I/O processing. Thisapproach will eliminate the large delayintroduced by the per-packet Transmis-sion Control Protocol/Internet Protocol(TCP/IP) processing overhead.

Since our network design goal isto facilitate the performance of realapplications, Sandia will evaluate theabove LAN technologies in the contextof working applications on a small test-bed. We will evaluate performance ofvery large networks with thousands ofinterconnections using modeling and

simulation tools developed in thisproject. These modeling and simulationtools will be invaluable in designing thenext-generation interconnect for a largeCplant system and its associatedapplications. In addition, we willevaluate the ability of techniques suchas priority queuing, enhanced message-passing algorithms, network–basedmulticast/broadcast, and cut-throughrouting to increase throughput andreduce latency and congestion.

During the previous year wecompleted studies on LAN intercon-nect technology trends, procured andgained experience with MIL3 OPNETmodeling and simulation tool, anddesigned and implemented foursimulation models: (1) VIA networkmodel, (2) layer-2 and -3 GigabitEthernet model, (3) Myrinet model,and (4) a 2-D mesh and a smooth-particle hydrodynamic parallelalgorithm model. We developed themodels to provide us with a flexiblemethod to predict network perfor-mance for large-scale systems (thou-sands of nodes). The developed VIAmodel provides the foundation fortesting and evaluating various OSbypass strategies. There are currentlytwo leading contenders: VIA andscheduled transmission (ST). TheGigabit Ethernet, Myrinet, and Giganethardware technology models providethe foundation for predicting theperformance of different networkingtechnologies and the effect on systemperformance when these technologiesare combined. The two applicationsmodels will be critical tools in evaluat-ing how representative applicationswill perform on large-scale multipro-cessor systems.

On the hardware side, wedeveloped and implemented a small,four-node cluster and installed VIA-compliant hardware. We obtained,debugged, and implemented a comple-mentary set of initial VIA softwaredrivers. We conducted initial VIAperformance testing to obtain baselinemetrics to be applied to the design of amore complex test-bed. These initialtest results provided the foundationfor the development of a larger testthat is currently under construction.

Publications

Other

Canady, C., and P. Wyckoff. 1998.“Bobnet: High-Performance MessagePassing for Commodity NetworkingComponents.” Proc. 2nd IASTEDInternat. Conf., Parallel and DistributedComputing and Networks (PDCN ’98)(Brisbane, Australia, 14–16 December).

3512.240

Low-Power, Reduced-Computation, Public-KeyProtocols

V. A. Hamilton, E. V. Thomas, R. A.Gonzales, T. J. Draelos, A. M. Johnston

Public-key cryptography can beused to provide privacy, data authentica-tion, and nonrepudiation. The advan-tage of public-key cryptography is theease of key management in terms of theamount of data that must be protected(i.e., private keys). For instance, asingle authenticated message can beverified by multiple parties, each ofwhom requires access only to theappropriate public key. This feature isadvantageous in remote monitoringapplications in support of multilateraltreaties, in critical infrastructureapplications, and in the area of emerg-ing threats. In addition, investigators onthis project currently support nuclearweapons applications in which lowerresource public-key authenticationmechanisms would be very valuable. Nosolutions to the problem of computa-tional intensity exist, and while keymanagement issues are minimized inpublic-key applications, they are notinconsequential. System developers willoften use symmetric or private-keytechniques where power or computa-tional capabilities are limited and thenre-encrypt or re-authenticate at someintermediate system. We authenticatethe data (in the case of authentication)only from the intermediate system, notfrom the data originator. Therefore,source-to-sink data authentication, whiledesirable, is often difficult to achieve.Sandia can enhance its current crypto-graphic capabilities and leadership in


defense and industry by developing aninnovative solution(s) to these prob-lems. This project will research anddevelop mechanisms that will enablethe use of public-key cryptography inlow-power and/or reduced-computationenvironments by investigations inseveral technical areas, includingnumber theoretic, one-time, probabilis-tic, and polynomial techniques, therebyenhancing the chances of projectsuccess.

• We researched and docu-mented candidates for baseline public-key protocols/algorithms. Threeclasses of algorithms appearedpromising: number theoretic, one-time,and probabilistic algorithms.

• We documented proposedmodifications of existing baselinepublic-key protocol/algorithm candi-dates and/or new protocols/algo-rithms. Modifications to the baselinealgorithms include performanceenhancements to the number theoreticschemes, conversion of one-timeschemes to multiple-use schemes, andconversion of probabilistic identifica-tion protocols to authenticationprotocols.

• We researched and docu-mented candidates for baseline keymanagement techniques. Convertedone-time protocols require signifi-cantly modified key managementmethods primarily to include authenti-cation trees. We researched anddocumented these requirements alongwith methods to optimize these datastructures. Probabilistic protocolsrequire slight modifications to stan-dard mechanisms since these types ofalgorithms have never been consid-ered by developers of the standardtechniques.

• We surveyed and documentedhardware candidates, smart card,custom, and general purpose. Wedeveloped proposed changes in designcapability. We performed a survey ofthe computing platform and seg-mented the evaluation into two majorcategories: (1) general-purposecommercial devices, and (2) special-purpose/custom platforms.

We also investigated polynomialalgorithms.

3512.270

AVATAR—Navigating andMining in Massive Data

W. P. Kegelmeyer

The sheer scale of modern datasets defeats attempts to understand thatdata. Even when coupled with advancedvisualization systems, the volume issuch that all data can no longer beavailable at a glance. Thoroughinspection is impossible, and yetinspection is necessary, especially whenthe phenomena of interest are easier torecognize than to describe.

This project will develop anadvanced tool for data “understanding,”one that supports exploration, easycollaboration, and knowledge encapsu-lation. The core idea is to exploitmassive parallelism and robust patternrecognition (PR) to manipulate derivedproperties of the data sets. This ap-proach is called AVATAR (AdaptiveVisualization Aid for Touring andRecovery) and will produce avatars,sophisticated user profiles that areattached to data. These, in turn, areexploited by the visualization tool,permitting the data to be understood in afashion uniquely adapted to a particularuser.

Sandia developed a powerful androbust PR method known as densefeature maps (DFM). We previouslyapplied DFM methods to a similarlydifficult problem, detection of cancer inmammograms, with noted success (twopatents, a commercial software license).We will use DFM here, as well, to extractthe avatars by invisibly watching how auser interacts with the data.

The end result will be prototypeAVATAR software, integrated with a 3-Dphysics visualization applicationalready in active use at Sandia with fulldocumentation. We will also report onperformance, treating both objectivemeasures of classification accuracy andsubjective feedback from interviews withusers.

• Parallel classification. Wecompleted a full literature search intothe field of classifier parallelization.

We ported three matureparallelized classification algorithms tothe Accelerated Strategic ComputingInitiative (ASCI) machine.

We made substantial improve-ments to the ScalParC parallel classifi-cation algorithm, to include adapting itto handle continuous valued featuresand improving its load-balancing andcommunication overhead.

We also developed and imple-mented a promising and intriguinglycounter-intuitive approach. This newmethod grows trees on disjointsubsets of data, then merges the treesat the end.

We acquired real data setsranging up to 10 Mbytes, along with agenerator that can create syntheticdata sets of any size.

• Human factors. We evaluatedMeshTV, IBM DX, and MUSTAFA, andselected and installed MUSTAFA as thebase visualization tool.

We conducted user interviews;those results shifted saliency measuresaway from time spent investigating aregion to number and nature ofoperations applied to a region.

We developed methods forextracting initial saliency figures fromhuman operators, as these are neededto create realistic training data sets.

We implemented initial saliencydetection measures and inserted theminto the MUSTAFA user interface anddata model.

Publications

Refereed

Hall, L., N. Chawla, and K. Bowyer.1998. “Combining Decision TreesLearned in Parallel.” Proc. 1998Distributed Data Mining Workshop (NewYork, NY, 27–28 August).

Hall, L., N. Chawla, and K. Bowyer.1998. “Decision Tree Learning on VeryLarge Data Sets.” Proc. 1998 IEEE Conf.on Systems, Man, and Cybernetics (SanDiego, CA, 11–14 October).










PRECISION

SENSING

& ANALYSIS

Sensing technologies are being used to solvemore and more complex problems. Uses for sensorsrange from battlefield applications to undergroundfacility detection to environmental cleanup. LDRDsupports development of sensors to measure andhelp researchers understand phenomena that in thepast had been unobservable. There are six objectives in Precision Sensing andAnalysis: (1) develop physical imaging techniquesto view concealed or difficult-to-view objects;(2) develop distributed sensor systems that willmonitor complex systems such as battlefields ormanufacturing processes; (3) develop a distributedcommand-and-control system for diverse militaryassets; (4) develop algorithms and sensing capabilitiesfor autonomous navigation in complex environments;(5) develop precise, dexterous robotic manipulationcapabilities; and (6) develop advanced chemical andbiological sensors that can detect minute quantitiesof specific chemicals in a field environment and inreal time. There are many military applications where fast,efficient spectral imaging is necessary. Hyperspectralimaging (HSI) is a remote-sensing technique that isgaining significant attention for its unique ability toallow passive identification of materials in a scene.To achieve this, HSI systems acquire high-resolutionsimultaneous images in hundreds of spectral bands,generating a significant volume of data for a singleimage. This makes data acquisition and processingdifficult and limits the ability to do real-time targetdetection with HSI. Information-efficient spectralimaging sensor (ISIS) is an optical system conceptdesigned to significantly reduce data rates comparedto HSI systems, and it allows on-the-fly targetdiscrimination while retaining similar spectral detail.Most applications experience at least a factor of fiftyreductions in data rate and signal-to-noiseimprovements of a factor of ten over traditional HSIsystems with similar specifications. ISIS also offers opportunities for advances inmanufacturing and medical imaging. Large volumesof data are examined in counting cancerous cells orlooking for semiconductor defects. Faster, moreefficient data analysis would benefit manydiverse fields.





3516.080

Sampling and SensingSystems for High-PriorityAnalytes

G. C. Frye-Mason, D. Y. Sasaki, A.Sellinger, R. J. Kottenstette, C. J. Brinker,G. C. Osbourn, P. R. Lewis

This project focused on redesign-ing current array–based sensing systemsto optimize them for detecting high-priority analytes (HPAs) such aschemical warfare (CW) agents, CWprecursors, and explosives in thepresence of common interferants. Sincethe target HPAs have either low volatilityor high reactivity, their analysis willrequire modifications in adsorbentmaterials and surface acoustic-wave(SAW) sensor-array coatings. The teamof investigators assembled to performthis project demonstrated leadership inthe areas of SAW sensor systems, thin-film adsorbents and coating materials,pattern recognition (PR) analysis, andchemical microanalysis, which makesthis team uniquely qualified to take onthis task. The materials and systemoptimization performed will facilitatedevelopment of low-power, microanalyti-cal systems (chemistry laboratory-on-a-chip) that could provide rapid, sensitive,and selective detection of these HPAs intruly miniaturized field-deployable units.Spin-off applications in environmentalmonitoring and industrial processcontrol are likely for other classes ofsemivolatile chemicals (e.g., pesticides,sludges) that are notoriously difficult tomonitor.

Accomplishments includedsynthesis and testing of newderivatized sol-gel and reactivepolymer coatings for SAWs. The sol-gelcoatings continue to show very highuptakes of the semivolatile analytessuch as dimethylmethylphosphonate(DMMP). Because of the high activityof these materials, they require largesample volumes at low concentrationsto accumulate enough analyte toequilibrate the surfaces. In addition,the release at room temperature isslow. However, tests using thesematerials on thermal desorptionplatforms verified rapid release withpulsewidths of under 200 ms uponrapid heating to 200°C. This verifiesthe utility of these materials for samplepreconcentration. In addition, wedemonstrated reversible responses onSAW sensors at elevated temperatures(80°–100°C). At these temperatures,uptake of potentially interferingcompounds should be low, enhancingthe selectivity of these materials.

Another highlight was thedemonstration of a material fordetecting reactive species such asphosphorous oxychloride. Thesecompounds are used in the productionof CW agents and could be usefultargets for detection. The challenge foran SAW sensor is that these com-pounds have high volatility, makingthem hard to collect on the sensorsurfaces, and they are reactive, so theymay not survive for long on the sensor.We decided to look at the use ofmaterials that would irreversibly reactwith these compounds so we could

form a dosimetric sensor with thepotential for trace detection of thesereactive precursors. We successfullydemonstrated this concept using apolyacrylic acid/polyacrylamidecopolymer that exhibited an 80 mdeg/min response when exposed to 100ppb of phosphorous oxychloride. Incontrast, a polyvinylalcohol-coateddevice exhibited no detectableresponse. This demonstrated proof-of-principle for sensitive and selectivedetection of these types of com-pounds. With further optimization, thisnew capability will enable us todevelop systems for detecting abroader range of compounds relevantfor nonproliferation of CW agents.

Publications

Refereed

Frye-Mason, G. C., R. J. Kottenstette, E.J. Heller, C. M. Matzke, S. A.Casalnuovo, P. R. Lewis, R. P.Manginell, W. K. Schubert, and V. M.Hietala. 1998. “Integrated ChemicalAnalysis Systems for Gas-Phase CWAgent Detection.” Proc. Micro TotalAnalyt. Systems Conf. (Banff, Canada,12–16 October): 477–481.

Lewis, P. R., G. C. Frye-Mason, R. J.Kottenstette, and J. Vitko, Jr. 1998.“MicroChemLab: An Update on theIntegrated Chemical Analysis Systemfor CW Agent Detection.” Proc. MASINTChemical Def. Sci. & Tech. Symp.(Aberdeen, MD, 9–11 June).


3516.050

Electrokinetic ImmunoaffinityChemical Sensors

J. S. Schoeniger, J. V. Volponi, D. H.Thomas, D. S. Anex, V. A. Vandernoot,D. W. Neyer

The purpose of this project is toestablish the feasibility of capillaryaffinity electrochromatography (CAEC)with laser-induced fluorescence (LIF)detection as a portable means for thedetection of trace quantities of toxins inliquid samples. The project focuses onthe detection of analytes for which thereis currently no portable sensor capabil-ity with adequate sensitivity andspecificity, e.g., potential biologicalwarfare (BW) agents (bacterial toxins).In CAEC, the chromatographic matrixconsists of immobilized molecularrecognition materials (MRMs), (e.g.,antibodies [Abs] or receptors) that bindselectively to the target analyte, surpass-ing the specificity of capillaryelectrochromatography (CEC). A sensorbased on CAEC has the potential tocombine the versatility of CEC, the highsensitivity of LIF, and the exquisiteselectivity of molecular recognition. Weobtained new results regarding both thescientific basis of CAEC and the technol-ogy required to implement effective,field-portable CAEC–LIF units for toxindetection.

We demonstrated the first-everimplementation of CAEC. In thissecond year, we completed a morethorough scientific investigation of thefundamental processes involved in,and the practical measures necessaryto implement, CAEC–LIF for measure-ment of biological toxins. To under-stand the similarities and differencesbetween CAEC and traditional affinitychromatography, we successfullyquantitatively modeled and comparedto experiment CAEC of small analytes.

Building on this work, we alsoimplemented affinity chromatography

on macromolecular analytes. Initially,attempts at CEC on proteins usingtraditional nanoporous silica chro-matographic supports were unsuccess-ful. Further investigation revealed apreviously unknown, but potentiallyextremely useful, size-dependentreversible electrokinetic (EK) trappingeffect. We showed that this effect canbe used to concentrate proteinanalytes by factors greater than 1000and are presently completing atechnical disclosure based on suchsystems.

We also showed that we mayavoid trapping by using nonporoussilica microspheres as chromato-graphic supports. We thereforesynthesized nonporous affinity phases.To meet stability and sensitivityrequirements for fieldable/portabletoxin detection systems, we focusedon synthesizing non-Ab–based affinityphases because we wanted to useaffinity ligands with enhanced stability.This required the development ofmethods for immobilizing carbohy-drate or synthetic peptide toxinreceptors on silica supports. Usingboth pressure-driven and EK flow, weare currently characterizing theretention and elution of affinity phasesfor the toxic protein ricin, andpeptide–based affinity systems formodel proteins.

Finally, we constructed andevaluated a prototype field-portableLIF apparatus with photon-countingdetection. We demonstrated concen-tration sensitivity with this apparatusdown to subnanomolar levels.

Publications

Refereed

Thomas, D. H., J. S. Schoeniger, D. L.Rakestraw, V. Lopez-Avilla, and J. M.Van Emon. 1998. “Selective TraceEnrichment by Immunoaffinity Capil-lary Electrochromatography.” Electro-phoresis, accepted.

3516.060

Information-Efficient SpectralImaging System (ISIS)

S. M. Gentry, W. C. Sweatt, J. W. Daniels,R. J. Blake, M. K. Hinckley, L. J. Krumel,B. R. Stallard, D. A. Smith

Hyperspectral imaging (HSI) is aremote sensing technique that is gainingsignificant attention for its unique abilityto allow passive identification ofmaterials in a scene. To achieve this,HSI systems acquire high-resolutionsimultaneous images in hundreds ofspectral bands, generating a significantvolume of data for a single image. Thismakes data acquisition and processingdifficult and limits the ability to do real-time target detection with HSI. Inaddition, signal-to-noise ratio is compro-mised by parsing the photons among alarge number of spectral bins. Informa-tion-Efficient Spectral Imaging Sensor(ISIS) is an optical system conceptdesigned to significantly reduce datarates compared to HSI systems, and itallows on-the-fly target discriminationwith minimal processing overhead,while retaining similar spectral specific-ity. ISIS allows the optical selection andmixing of key spectral image compo-nents into a small number of outputsrelated to target identification. Mostapplications experience at least a factor-of-fifty reduction in data rate and signal-to-noise improvements of a factor of tenover traditional HSI systems with similarspecifications.

The project was successful indeveloping an imaging instrumentoperating in the silicon (Si) spectralregion (0.45–1.05 µm) that is able todiscriminate between a camouflagedHUMVEE and natural desert scrubbackground scenery. We conducted fieldtests at Coyote Canyon on Kirtland AirForce Base.

(1) We designed, fabricated, andtested an ISIS field-test instrumentoperating in the Si spectral region. Theinstrument is capable of achieving 5nm spectral resolution over 0.45–1.05


µm and can resolve 500 spatialsamples over a 5-degree field.

(2) We utilized the ISIS field-testinstrument at Sandia’s Coyote Canyontest site to evaluate the ability todiscriminate a camouflaged NationalGuard HUMVEE from the naturalvegetative background. Tests weresuccessful when the HUMVEE wasunder camouflage, but the materialvariability of the uncovered HUMVEEmade it more difficult to discern. Weexpect different spectral regions andthe use of more complex filter vectorsettings to remedy this difficulty.

(3) We developed a variety ofmethods for synthesizing filter vectorprograms utilizing source spectral datacollected with the instrument.

(4) We developed a potentialWork for Others (WFO) customer tocarry the ISIS research forward tooperational stages.

Publications

Other

Gentry, S. M., and B. R. Stallard. 1998.“Theoretical Analysis of the Sensitivityand Speed Improvement of ISIS over aComparable Traditional HyperspectralImager.” Sandia Technical ReportSAND98-1887 (September). SandiaNational Laboratories, Albuquerque,NM.

Stallard, B. R., and S. M. Gentry. 1998.“Construction of Filter Vectors for theInformation-Efficient Spectral ImagingSensor.” Proc. SPIE, accepted.

Stallard, B. R., S. M. Gentry, W. C.Sweatt, S. E. Motomatsu, and C. A.Boye. 1997. “Principles and SatelliteApplications of the Information-Efficient Spectral Imaging Sensor.”Sandia Technical Report SAND97-1493(June). Sandia National Laboratories,Albuquerque, NM.

Sweatt, W. C., C. A. Boye, S. M. Gentry,M. R. Descour, B. R. Stallard, and C. L.Grotbeck. 1998. “ISIS: An Information-Efficient Spectral Imaging System.”Proc. SPIE, accepted.

3516.070

Imaging of Moving TargetsUsing SimultaneousSynthetic Aperture Radar(SAR) and Moving TargetIndicator (MTI) Radar

J. T. Cordaro, C. V. Jakowatz, Jr., J. A.Hollowell

Sandia will combine two well-known radar techniques and an adapta-tion of an existing algorithm to imagemoving targets. Synthetic aperture radar(SAR) images objects at known veloci-ties relative to the SAR platform. In SARthe motion relative to objects that arefixed on the Earth is accomplished byusing inertial measurement systems andthe global positioning system (GPS).Targets that move over the Earth aredisplaced and defocused because ofunknown motion components. This factobscures information about the target inthe SAR image. Moving target indicator(MTI) radars measure the relativeposition and velocity of objects that aremoving over the Earth, but they do notproduce an image of the moving target.While traditional MTI radars measurethe average radial velocity of the target,higher-order motion components are notmeasured. This prevents formation of agood-quality, fine-resolution image of themoving target. Even the straightforwardcombination of these two radar tech-niques will have significant limitations.The information necessary to form theimage of the moving target is containedin the raw data; however, it must beextracted by a suitable algorithm.

In SAR, inaccuracies in inertialmeasurement systems typically result inunsensed radar platform motion.Generation of well-focused, fine-resolution SAR images requires compen-sation for this unsensed motion. Wedemonstrated great success at estimatingthe unknown radar platform motion

using phase-gradient autofocus (PGA).This type of algorithm should also havesuccess in estimating the higher-ordermotions of a moving target. Ourapproach will be to combine theinformation from an MTI radar with analgorithm similar to PGA to estimate thephase errors in the moving target data,compensate for those errors, produce animage of the moving target, and placethe image of the moving target in theproper place in the SAR image.

Our work consisted of twoalgorithm-development efforts plus aTwin-Otter-radar data collection. Thefirst algorithm effort aims at focusingmoving targets after they have beendetected in SAR data. We successfullytested the method on data collected atthe end of FY97. For this initial test,the targets were traveling at constantvelocity along straight roads. Wemodeled target motion in terms ofrange and cross-range velocities. Acontrast optimization techniquesearches over the resulting 2-D spaceto achieve the best focus.

The second algorithm effortimplements simultaneous SAR/MTI todetect moving targets and to thenreposition them in an image. Slow-moving targets remain in the clutter(endoclutter targets) and must bedistinguished from stationary objects.We developed a method to use SARdata from two antenna phase centersto reduce stationary clutter fordetection and measure target angle forrelocation. We successfully tested thealgorithm on data from the FY97collection.

We recently completed a seconddata collection. For this test, themoving targets executed a variety ofmotions. On straight roads, the targetsaccelerated to different velocities.Three vehicles did start-stop-passingdrills; one vehicle moved in a circle. Allthis will provide challenging data forour algorithms.


3516.090

Automated Vegetation HeightMeasurement for AutomaticTerrain Mapping

J. R. Fellerhoff, D. L. Bickel, M. L. Yee

Sandia demonstrated that inter-ferometric synthetic aperture radar(IFSAR) accurately measures the tops ofvegetation. A map of the tops ofvegetation is sufficient for airborne usersof terrain elevation information;however, troops or personnel in groundvehicles need to know the terrain belowthe vegetation. Many commercial andcivilian map users require ground-levelinformation rather than vegetation-topinformation, as well. A proof-of-principleof under-tree, ground-level terrainmapping is the primary goal of theproject. Research from Sandia’s High-Altitude Doppler Radar Altimeter(HIDRA) work shows that in manyforested areas, radar altimeters receivea significant return from the top of thetrees as well as the terrain underneath.We are studying the combination ofthese two radar techniques to measurenot only the elevation of tree tops butthe terrain underneath. IFSAR is atechnology that has the potential tosatisfy the high demand for accurate andtimely terrain data from both govern-ment and commercial entities. It is likelyto become a necessary feature on mostfuture imaging radar systems. Solvingthis problem could help keep Sandia intechnological leadership in this ex-tremely important area. A second goalof the project is the understanding of theexact relationship between IFSAR andHIDRA data in vegetated areas, as this isalso an important problem for the newgeneration of weapon guidance systemsbased on imaging altimeter technology.This study will provide much insight intothat relationship. A third importantresult from this study will be the ability

to detect, classify, and quantify vegeta-tion regions in IFSAR elevation models.This could be important to automatictarget recognition (ATR) in cueing thealgorithms to use different recognitionmethods, depending on the vegetationtype and height.

In the first year we collected andprocessed IFSAR data from the bosquewhere I-25 crosses the Rio Grande nearBlack Mesa, south of Albuquerque,NM. We also processed existing HIDRAdata from the same flight path taken inSeptember 1995. (HIDRA was unavail-able in the first half of 1997.) Mappingthe HIDRA data onto the IFSAR datashowed there were a large number ofHIDRA ground returns in areas coveredby trees. In a number of areas wherethe IFSAR data measured the treeprofile, the HIDRA data provided ameasurement of the underlying groundprofile. We can then determinevegetation height by taking thedifference of the IFSAR tree profile andthe HIDRA ground profile. Thisdemonstrated the basic capability ofcombined IFSAR and HIDRA data tomeasure both vegetation height andthe terrain height underneath thevegetation.

In the second year we collectednew data from a newly developedHIDRA sensor. This HIDRA is optimizedfor the down-looking mode of opera-tion and is more representative of anoperation sensor. The results from thisyear clearly show that terrain features(significant ditches, sloped terrain)beneath the trees are visible to thissensor.

Publications

Other

Fellerhoff, R. 1998. “Bald Earth Map-ping Research.” Formal briefings ofresults to DARPA, AF RMAG, and JPSD,Washington, DC, May.

3516.110

Sparse GeophysicalNetworks for MonitoringDeep Targets

G. E. Sleefe, A. A. Yee, L. C. Bartel, M. D.Ladd, H. D. Garbin, J. P. Claassen, G. J.Elbring

Facilities for the manufacture andstorage of weapons of mass destruction(WMD) are often contained withindeeply buried structures or tunnels. Theability to detect, characterize, andmonitor these deep undergroundproduction and storage sites is critical tothe defeat of these threats to ournational defense. The intent of thisproject is to focus on the key technologyissues required to bring a deep-targetunattended ground sensor system tofruition. In particular, the use of a sparseseismic network is very desirable forthis application since it represents apractical field-deployable configuration.However, the application of sparsenetworks for accurately determining the3-D location of underground activitieshas never been addressed. As such,Sandia will design, develop, and test anadvanced algorithm that uses sparseseismic networks to accurately deter-mine the 3-D location of undergroundactivity, especially activities of acontinuous nature. The algorithm willincorporate several novel elements toaddress the sparse network problem:(1) the use of enhanced 3-D geophysicalmodeling to optimize sensor layout anddistribution, (2) the isolation of localsoil effects by using both velocityinversion and spectral ratio methods,(3) the use of modified array processingmethods to handle the spatially aliasednetwork data set, (4) the incorporationof an active calibration source toremove geophysical biases, and (5)resonance-extraction techniques to inferunderground cavity dimensions. Tovalidate these advanced geophysicaland signal-processing methods, we will


process data previously acquired at theNevada Test Site (NTS) P-tunnel usingthe novel algorithms. Additionally, wewill collect a small data set at theP-tunnel to confirm the optimized sparsenetwork approach.

We made significant progress inthe development of a novel algorithmfor locating underground targetactivity using sparse seismic networks.We formalized the framework of thealgorithm, which includes 3-D forwardseismic modeling, geologic mediumestimation, and model–based seismicsignal processing. Within this frame-work, we made significant technicalprogress on each aspect of thealgorithm. In the modeling area, wedeveloped a fully elastic seismic 3-Dfinite-difference model and imple-mented it on an engineering work-station. We optimized the code to runefficiently; it can handle complexunderground seismic sources includ-ing rotary torque and shear motions.We tested the model and successfullygenerated synthetic surface seismo-grams resulting from a source in anunderground void. We successfullycompleted the second aspect of thealgorithm: geologic estimation. Aspectral ratio algorithm, based on theHaskell-Thompson formulation,enables the estimation of subsurfacegeology from passive surface seismicobservations. We successfully appliedthis geologic estimation method usingdata from the P-tunnel. We also madesubstantial progress in developingmodel–based seismic signal-processingtechniques to perform undergroundsource localization. The signal-processing techniques under investiga-tion include advanced array process-ing for bearing estimation, cross-correlation for continuous sourcetiming estimates, and improving theLOCSAT (software package) locationestimator, to include 3-D ray tracingand optimized use of both bearing andtime-of-arrival inputs.

3516.120

Miniature BioaerosolConcentrator

K. Wally, D. J. Rader, S. H. Kravitz, R. F.Renzi, M. X. Tan

To be most effective, biologicalwarfare agent (BWA) sensors mustdetect BWA bioaerosols at concentra-tions as diffuse as one pathogen particleper liter of air. The most capable port-able miniature BWA detectors underdevelopment employ techniques ofbiological or chemical detection inaqueous or solvent solution. Thesetechniques, miniaturized to the micro-fluidic level, typically require an influentconcentration of ten bioparticles permicroliter of solvent. Demonstrably,therefore, there is a pressing need for adevice to couple these conditions, i.e., tocollect highly diffuse bioaerosols andconcentrate them into microfluidicvolumes for further analysis. For hand-portable detectors, such a device mustbe both battery-operable and minia-ture—only one or two cubic inches involume. Unlike existing miniatureaerosol collectors, which fall short inone area or another, Sandia’s miniaturebioaerosol concentrator satisfies allthese requirements. A unique integrationof science, process, and engineering isthe key. First, ours will be a truebioaerosol collector in that bioaffinitydetection techniques require that surfaceproteins on collected particles beunscathed by collection processes.Therefore, our collector uses only benigntechniques of inertial separation andvirtual impingement into aqueoussolvent to collect particles. Second, ourdevice concentrates bioaerosol particlesinto a mere microliter of aqueoussolvent. This is a concentration severalorders of magnitude greater than thebest currently achieved in miniatureaerosol collectors. We can achieve thisthrough development of microseparatorand microimpinger stages employing theprinciples of aerodynamic particlelenses and electrokinetic (EK) fluid flow,all realized through techniques ofminiature fabrication (i.e., LIGA[German for lithography, electroforming,and molding] or Bosch deep-etched

silicon). Third, in our concentrator thesampling fan and its motor are miniatur-ized, integral to the device, and ac-counted in its tiny package volume.Existing miniature collector/concentra-tors achieve miniaturization only bydepending on external apparatus forsample air flow.

The scope of first-year workconcentrated on refining issues oftechnical feasibility. As a result, twokey uncertainties appear on the way toresolution. The first was whether therequired volume of air could be drawnthrough the proposed microseparatorby a miniature high-speed fan ofconventional design. We developed acomputer model for separation andcollection of bioaerosol particles (i.e.,particles 1 to 5 microns in size) usingthe FIDAP 7.60 commercial finite-element (FE) gas dynamics code tomesh the selected geometry andcalculate air flow and particle trajecto-ries. We identified a promising geom-etry that exploits the concept of theaerodynamic lens. Preliminary resultssuggest that the aerodynamic lens mayenable collection of 1- to 5-micronbioaerosol particles directly in onesingle-stage inertial separation ratherthan the two stages postulated in ouroriginal proposal. The second uncer-tainty was whether microfluidic EKpumping could generate the flow ratesneeded to transport particles collectedin open microchannels. We recentlycompleted design and fabrication of anEK pump that preliminarily demon-strated the feasibility of achieving highflow rates. The EK pumping mecha-nism consists of thin wafers ofmicroporous alumina. These dielectricstructures, comprising short, mas-sively parallel (MP) microchannels(each under 20 microns in diameter),produce relatively high EK flows(substantially greater than tens ofnanoliters/second) roughly propor-tional to the face area of the wafer, butproducing little hydraulic head due tothe wafer’s overall thinness. This isprecisely the pump characteristic wedesire for open channel flow, wherehigh flow rate is needed to transportparticles, but excessive hydraulic headrisks overflowing channels.


3516.130

Recognizing PartiallyObscured Targets byCombining Multiple DataSources Using EvidentialReasoning

M. W. Koch, D. A. Yocky, J. S. Salazar, M.M. Moya

Military commanders in thebattlefield need accurate, reliable targetinformation. Yet any single sensor hasnecessarily limited detection capabilityand inherent sensitivities to some falsetargets. Multiple sensors, particularlythose with different sensing modalities,can provide complementary targetinformation. However, even smallincreases in amounts of sensor data canquickly overwhelm a human analyst.Automating the target recognitionprocess by combining data from multiplesensors to produce a single likelihoodfor each target’s existence/location canassist analysts in identifying significantthreats.

Sensor evidence is typicallyuncertain; it allows for multiple interpre-tations, which can be incomplete (i.e., asensor rarely has a full view of thesituation) and/or conflicting (e.g., asensor may be partially incorrect).Because of these characteristics, Sandiacombined evidence from multiplesensors using an evidential reasoningengine. First, we extracted evidencefrom the different sensors by applyingimage-processing and pattern recogni-tion (PR) algorithms to identify targetsubparts or chunks. Each of thesefeature-level chunk detectors functionsas a separate knowledge source, which

provides evidence to the reasoningengine. Since we could tailor thealgorithms to exploit each sensor’sunique characteristics, we maximizedthe relevance of each sensor’s informa-tion.

The reasoning engine representsits knowledge of the target as multiple-level frames of discernment, where eachsensor target template comprises aspatially registered combination ofchunks. The engine updates contextualevidence for the presence of targetchunks by examining the similarity andcompatibility evidence from otherchunks. It updates evidence for thepresence of target templates based oninformation from individual chunks,where missing chunks can providenegative evidence. Thus, the evidentialreasoning engine provides a formalizedmethodology for combining incompleteand uncertain evidence from feature-level sensor chunks to allow recognitionof partially obscured targets.

We developed an evidentialreasoning engine that combinesevidence from multiple syntheticaperture radar (SAR) chunks. We alsodeveloped and implemented algo-rithms for matching SAR target chunkswith test images. For each chunk, wemeasured a chunk’s intrinsic andcontextual support by computing themean square error between a chunk orchunk pairs and a possible location inan image. The evidential reasoningapproach represents the evidence inframes. Each frame specifies a set ofpossible situations, and basic probabil-ity assignments represent evidencerelative to the frames. Relationshipsbetween the frames and Dempster’srule allow the gathering of contextual

evidence for a chunk and evidence fora set of chunky templates. Using actualSAR data of a SCUD target, we deter-mined the detection and false-alarmrate characteristics for the chunkyevidential reasoning algorithm. We alsocollected multisensor data from seventarget vehicles at Kirtland Air ForceBase and urban clutter from Albuquer-que using the Otter SAR and theRemote Sensing Lab Daedalus multi-spectral (MS) sensor. We developedMS target material detection algo-rithms, which detect single-pixel MSchunks, for future incorporation intothe evidential reasoning.

Publications

Other

Koch, M. W., J. S. Salazar, M. M. Moya,and D. A. Yocky. 1998. “RecognizingPartially Obscured Targets by Combin-ing Multiple Data Sources UsingEvidential Reasoning.” Presentation atDIA Meeting, Sandia National Laborato-ries, Albuquerque, NM, 23 June.

Koch, M. W., J. S. Salazar, M. M. Moya,and D. A. Yocky. 1998. “RecognizingPartially Obscured Targets by Combin-ing Multiple Data Sources UsingEvidential Reasoning.” Presentation atmeeting with Captain Paul Schultz andLt. Dan Sunvolt, U.S. Navy, at SandiaNational Laboratories, Albuquerque,NM, 2 March.

Koch, M. W., J. S. Salazar, M. M. Moya,and D. A. Yocky. 1998. “RecognizingPartially Obscured Targets by Combin-ing Multiple Data Sources UsingEvidential Reasoning.” Presentation atmeeting with Gary Beeler, VP of Org.2500, Sandia National Laboratories,Albuquerque, NM, 8 April.


3516.140

Computational Engineeringof Sensor Materials andIntegration with a NovelBiological Weapon DetectionSystem

D. C. Roe, J. S. Schoeniger, S. Istrail

This project will develop thecomputational tools to efficiently designcombinatorial peptides (CPs) for use assensor materials in the detection ofbioagents. A necessary step in sensordesign is to discover a material thatbinds and molecularly recognizes atarget biomolecule. CPs are a new classof molecular recognition materials(MRMs) based on small molecules thatcan be engineered to bind tightly andspecifically to a target analyte. Theyhave a significant advantage overantibodies and enzymes in that they aremuch more rugged, cheaper, and moreversatile. However, identifying highlyselective CPs can be time-consuming,since potentially 1012 CPs may bepossible, but only 105 compounds canbe tested at a time. Sandia usedcomputational modeling of molecularrecognition and developed a uniquesoftware algorithm, shuffle-and-screen,that will greatly enhance the efficiencyof the sorting process to discover highlyselect CPs. In our approach, we gener-ated CP MRMs in a simplified three-stepprocess. First, we used bead synthesis tocreate and evaluate an initial set of CPs

specific for a target analyte. Second, weapplied a novel computational molecu-lar recognition (CMR) shuffle-and screenalgorithm to abstract the key interactionproperties of the most promisingcandidates of the initial bead synthesis,and searched a virtual library of allpossible CPs for ones that contain thoserecognition features and thus may haveimproved detection properties. Third,we generated and tested these designedCPs in a second bead assay. The finalresult is CPs that are highly selective fora target analyte. The successful comple-tion of this project will have severalimportant impacts. The methodologydeveloped will enable rapid generationfor a broad range of other biologicalwarfare (BW) targets. The computa-tional methods developed will begenerally useful tools for all areas ofmolecular recognition.

We chose an initial set of testcases from a combinatorial library ofpotentially 1015 compounds to developour shuffle-and-screen algorithm. Wedeveloped a prototype algorithm thatanalyzes the key molecular recognitionfeatures of the top binders from aninitial bead assay. It searches a virtuallibrary of all possible CPs for ones thatcontain the same molecular recogni-tion features and therefore may haveimproved detection properties. Thekey molecular recognition features weanalyzed are a 2-D topological indexcalled the Wiener index that can beused to describe the similarity be-tween two chemical structures.

Approaches in the literature using thisindex usually employ genetic algo-rithms (whose results vary, dependingon the starting conditions) since itwould take roughly 37 years toexhaustively examine all 1015 possiblecompounds. Our algorithm takesadvantage of inherent redundancies inthe combinatorial compounds,reducing the search time to examineall possibilities from 37 years to lessthan a day. Experimentally we initiateda collaboration with North CarolinaState University to (1) perform initialbead assays on ovalbumin (as a testsystem) and then either SEB (Staphylo-coccal enterotoxin B) or C-fragment ofbotulinum toxin, and (2) performselectivity, competition, and sequenc-ing tests of 20 or so top candidates foreach analyte. We completed a prelimi-nary assay and currently are running afull-scale bead assay to search for CPsspecific to ovalbumin. So far, we havefound seven CPs with better than onemicromolar binding that we showed tobe selective for ovalbumin. We aresequencing these compounds.

Publications

Refereed

Goldman, D., S. Istrail, G. Lancia, A.Piccolboni, D. Roe, and B. Walenz.1998. “Efficient Algorithms for Design-ing Combinatorial Peptides.” Posterpresentation for Pacific Symposium onBiocomputing ’99, Kapalua, Maui, HI,4–9 January 1999, submitted.


3516.150

Biological Weapon DetectorUsing Bioaffinity ArrayImpedance Analysis withChemical AmplificationThrough Redox Recycling

A. W. Flounders, R. P. Janek, D. D. Chu,S. H. Kravitz, A. J. Ricco, R. C. Hughes,K. Wally, J. S. Schoeniger

Sandia will develop a novelstructure for ultra-sensitive detection (1particle per liter of air) of biologicalwarfare (BW) agents, e.g., anthrax, tothe sensor prototype stage. Surface-attached specific affinity components(antibodies, combinatorial peptides[CPs], or glycolipids) will capture aparticle on one element of a microelec-trode array monitored via impedanceanalysis transduction, chemicallyamplified through disruption of redoxrecycling. We monitored Faradaicimpedance using a reversible redoxcouple (e.g., Fe[(CN)6]-3/-4) recycledbetween its oxidation states by eachmicroelectrode and a shared counterelectrode. Capture of a single pathogenblocked one microelectrode, disruptingthe redox cycle at that electrode. Anarray of pathogen-sized, individuallymonitored, small-area (2x2 µm2)microelectrodes enables single-particledetection. Many identically coated arrayelements (100s–1000) covering onesurface of the flow cell enhances theprobability of single-particle capture andprovides interferant discrimination byspatio-temporal tracking of the capture/release of each particle traversing thecell. Small capture area is key to single-particle detection; a multi-element arrayis key to rapid response, realisticsample volume, and improved discrimi-nation. Because of large particle size,diffusion alone may not be sufficient forparticle movement through the flow cell.

We will also investigate electrophoreticor dielectrophoretic movement ofparticles through the flow cell.

We made significant progresstoward a proof-of-principle demonstra-tion of the sensor concept. We se-lected surrogate capture and analytematerials, identified the preferredelectrode material, and verified systemcompatibility of the redox couple. Wemaintained the parallel approachoutlined in the original proposal ofworking with commercially availablesingle electrodes while designing andfabricating a simple multi-elementarray. We investigated impedancecharacterization of surrogate bindingat a single electrode and found that itsupports the proposed sensor con-cept. We performed these measure-ments with a large electrode, andsignal represents binding of manysurrogate particles. We designed andfabricated a 20-element microelectrodearray. We packaged, encapsulated, andtested array chips. Microelectrodecurrents are reproducible, correspondwell with exposed electrode area, andare of suitable magnitude (nanoamp)to be monitored without additional on-chip amplification. We functionalizedthe microelectrode array with affinitycapture material (biotin), and surro-gate particles (latex beads) withcorresponding affinity recognitionmaterial (streptavidin). Particlecapture in the electrode capture wellled to a significant current decrease.Response was an abrupt (1-second),digital-like current decrease andpreferable to a gradual current decay.We have not yet demonstrated specificrecognition of surrogate materials.Because of the large (1–2-micrometer)diameter of the target particles,particle movement to the electrodesurface can not rely on diffusion alone.We are currently investigating tech-niques to electrophoretically moveparticles to the electrode surface.

3516.160

ATR / Exploitation UtilizingUltra–High-Resolution,Complex SAR Imaging

D. W. Harmony, P. H. Eichel, W. J. Bow,K. M. Simonson

The goal of this project is todevelop novel automatic target recogni-tion (ATR) and exploitation techniquesutilizing ultra–high-resolution as well ascomplex (magnitude, phase) syntheticaperture radar (SAR) imagery. CurrentATR techniques utilize classificationmetrics applied only to high-resolutionmagnitude images. Sandia will researchand develop new classification metricsand algorithms designed to takeadvantage of the increased informationcontent of the complex and ultra–high-resolution SAR imagery. The existingmajor DoD program developing next-generation algorithms reported resultsthree orders of magnitude short of theirprobability of detection (Pd) and false-alarm rate (FAR) goals. Analyses showthat significant increases in the numberof resolved scatterers as well asimprovements in the ability to localizethem are necessary before ATR cansuccessfully handle the extendedoperating conditions of partial obscura-tion, articulation, camouflage, etc. Thisis particularly true for small tacticaltargets where the number of imageresolution elements on target is limited.Our research will provide these neededimprovements and then some. Not onlywill we take advantage of the enhancedinformation content coming fromincreased signature bandwidth, but alsothis improved resolution will nowseparate the underlying scatters enoughto allow us to utilize the additionalinformation carried in the phase of thecomplex-image pixels. Other DoD effortsare under way, struggling to improveperformance by modifying their current


algorithms without upgrading thesensors. We believe, from a systemperspective, that our combination ofsensor resolution enhancements coupledwith new complex-image ATR algorithmswill significantly outperform these otherapproaches.

We completed a large ultra–high-resolution SAR data collection withover 1400 images, including approxi-mately 9500 target images. In additionto six target vehicles, we collected anumber of radar primitives as well as asmall amount of urban clutter. Webelieve that this collection givesSandia the largest database of ultra–high-resolution SAR target imagery inthe world.

We modified existing recognitionalgorithms to handle ultra–high-resolution data. These changesinvolved accounting for rotationaleffects so that estimation of signaturestatistics could be done accurately,even with the relatively sparse data setwe had for training.

We showed that sub-apertureprocessing can be used to determinewhich features in a single complex SARimage are stable throughout theaperture flown to collect the scene.This processing technique will be ofgreat value in determining whichfeatures are flat-plate flashes andwhich are behaving like true pointreturns.

We analyzed data generated witha popular synthetic data-generationtool (XPatch) to evaluate the possibil-ity of using synthetic data to augmentmeasured data. High computationalcost of signature generation and pooraccuracy of the signature phase andamplitude produced with the availablefacet target models lead us to recom-mend dropping this tool’s use for now.

Finally, work on a new stabilitymetric–based feature extraction andmatching technique is under way.










ENVIRONMENTAL

SCIENCES

Finding technical solutions to environ-mental issues is the thrust of this investment area.Three categories of study are supported: (1) sitecharacterization projects that typically use sensorsto monitor several aspects of one environment, suchas the air, water, and soil at a site; (2) industrial ecologyprojects that reduce waste and harmful industrial by-products as well as increase energy efficiently withoutsacrificing quality, reliability, and performance of aproduct; and (3) environmental science projectsconsisting of basic research that supportsbreakthroughs in nuclear stockpile stewardship. Over the years, many thousands of areas acrossthe country have been contaminated; DOE isresponsible for 10,000 of those sites and has allocated$60 billion for cleanup. The staggering costs of cleanupmean that only a fraction of the contaminated siteswill undergo active remediation. In some cases, naturewill be able to gradually attenuate the contaminants,particularly organic contaminants. In others, soil andgroundwater are contaminated with inorganicmaterials that will require remediation. DOE currentlyhas no established protocol by which to tell whethernature will be able to attenuate the contamination.DOE has asked Sandia Labs to take the lead indeveloping a DOE complex-wide natural attenuationprotocol. Researchers in the project titled “MechanisticModels for Radionuclide Desorption from Soils” arelooking for a way for site managers to answer thequestion, “Which ones do we have to clean up?” Sandiawill write the guidelines that DOE will follow in site�� Sandia has developed the MNAtoolbox for sitemanagers to use to screen sites for the potentialimplementation of MNA (monitored naturalattenuation). MNA refers to the reliance on naturalattenuation processes under a carefully controlledand monitored site cleanup approach. The Web–basedMNAtoolbox assesses the data about a particular siteand allows the site manager to make a decision aboutwhether or not to spend funds to clean up that site.By identifying and collecting the specific naturalmechanisms that remove contaminants from thesubsurface, Sandia researchers will make it possiblefor DOE to much more rapidly screen contaminatedsites than was previously possible. This will lead tohuge potential cost savings, in the millions of dollars.





3518.030

Designed MolecularRecognition Materials forChiral Sensors, Separations,and Catalytic Materials

T. M. Nenoff, J. A. Shelnutt

The goal of this project is todevelop materials that are highlysensitive and selective for chiralchemicals and biochemicals (such asinsecticides, herbicides, proteins, andnerve agents) to be used as sensors,catalysts, and separation membranes.Sandia is using molecular modelingmethods to tailor chiral molecularrecognition (CMR) sites with highaffinity and selectivity for specifiedagents. The work focuses on bothsilicate and nonsilicate materialsmodified with chirally pure functionalgroups for the catalysis or separations ofenantiomerically pure molecules. Weare using surfactant and quaternaryamine templating to synthesize porousframeworks containing mesopores of 30to 100 angstroms. We are using com-puter molecular modeling methods inthe design of these materials, especiallyin the chiral surface-modifying agents.We are also using molecular modeling topredict the catalytic and separationsselectivities of the modified mesoporousmaterials. The ability to design andsynthesize tailored asymmetric molecu-lar recognition sites for sensor coatingsallows a broader range of chemicals tobe sensed with the desired high sensitiv-ity and selectivity. Initial experimentstarget the selective sensing of small-molecule gases and nontoxic modelneural compounds. Further efforts willaddress designing sensors that greatlyextend the variety of resolvable chemi-cal species and forming a predictive,model–based method for developingadvanced sensors.

In this project we synthesizedand characterized both new chiralporphyrins and molecular sieves.

The chiral porphyrins include acomputer-designed and then synthe-sized Ni(II) tetra(cyclopropyl) porphy-rin (known as the “Venus fly trap”porphyrin) and the Zn(II) heptabromo-mono-2-methoxyphenyl-tetraphenylporphyrin. These mol-ecules are unique because they weredesigned, synthesized, and character-ized specifically for CMR. We coupledthese materials to silicate and sol-gelsupport materials by surface modifica-tion. We characterized them by Ramanspectroscopy, x-ray, and magic-angleopening nuclear magnetic resonance(MAS NMR), and showed them toretain their chirality; this is importantfor future use as a chiral separationsmaterial.

We also synthesized and charac-terized completely novel, chirallytemplated, inorganic (Zn/P) crystallinephases for separations. These phasesinclude 2-D layered phases and a 3-Dmesoporous phase. We showed thesephases to be very pH- and concentra-tion-dependent. Characterizationtechniques include transmissionelectron microscopy (TEM), x-raydiffraction, and thermal and elementalanalyses. Furthermore, we grew thesenew phases successfully as inorganicthin-film membranes. Permeationmodeling through the phases pre-dicted the type of separations capablewith these materials.

These important results led to atechnical advance.

Publication

Refereed

Drain, C. M., S. Gentemann, J. A.Roberts, N. Y. Nelson, C. J. Medforth, S.L. Jia, M. C. Simpson, K. M. Smith, J.Fajer, J. A. Shelnutt, and D. Holten.1998. “Picosecond to MicrosecondPhotodynamics of a Nonplanar NickelPorphyrin: Solvent Dielectric andTemperature Effects.” J. Amer. Chem.Soc. 120 (June): 3781.

Jia, S. L., J. Zhang, J. Ema, N. Nelson, C.J. Medforth, K. M. Smith, J. G. Ma, andJ. A. Shelnutt. 1998. “Axial LigandAffinity Variation Induced byNonplanar Distortion.” Abstracts ofPapers of the Amer. Chem. Soc. 310(Dallas, TX, March).

Jia, S. L., W. Jentzen, M. Shang, X. Z.Song, J. G. Ma, W. R. Scheidt, and J. A.Shelnutt. 1998. “Axial Coordination andConformational Heterogeneity ofNickel(II) TetraphenylporphyrinComplexes with Nitrogenous Bases.”Inorg. Chem. 37 (July): 4402.

Lemke, C., J. A. Shelnutt, J. M. E.Quirke, R. Schweitzer-Stenner, and W.Dreybrodt. 1998. “The Effect of Meso-Nitro-Substitution on Nickel(II)Porphyrins.” Paper presented to theBiophysical Society Meeting, KansasCity, MO, February.

Ma, J. G., M. Laberge, J. Zhang, S. L. Jia,J. M. Vanderkooi, and J. A. Shelnutt.1998. “Raman Spectroscopic Investiga-tion of Nickel Microperoxidase-11.”Biochemistry, accepted.

Nenoff, T. M., A. Chavez, S. G. Thoma,P. Provencio, and R. S. Maxwell. 1998.“Templated Inorganic Thin Films.”Proc. Mater. Res. Soc. Symp. (SanFrancisco, CA, April).

Nenoff, T. M., J. A. Shelnutt, S. G.Thoma, S. L. Jia, and P. Provencio.1998. “Chiral Templating and Modelingfor Separations and Catalysis.” Mater.Res. Bulletin, accepted.

Nenoff, T. M., S. G. Thoma, P.Provencio, and R. S. Maxwell. 1998.“Zinc Phosphate Phases Templatedwith the Chiral Molecule d-Glu-cosamine.” Chemistry of Mater.,accepted.

Shelnutt, J. A., A. L. Jia, T. M. Nenoff, C.M. Muzzi, C. J. Medforth, and K. M.Smith. 1998. “Computational Design ofChiral Catalysts Based on NovelNonplanar Chiroporphyrins.” Abstractsof Papers of the Amer. Chem. Soc. 21621 (Boston, MA, August).


3518.050

Rapid Screening of ComplexChemical Samples ViaCapillary Array Analysis

D. S. Anex, D. W. Neyer, D. M. Haaland,M. K. Alam, J. S. Schoeniger

Complete characterization ofcomplex chemical samples oftenrequires a series of time-consuminganalyses. A carefully designed parallelanalysis scheme can rapidly obtain andinterpret a unique chemical signaturefrom a complex sample. Toward thisgoal, Sandia developed a novel instru-ment and approach to sample analysisbased on simultaneous separations in aparallel array of capillary columns.Each column in the array is individuallyoptimized to probe a particular broadchemical characteristic of the sample.The array of columns is bundled in aninstrument designed for simultaneousdetection of the signals generated ateach column. Since a particular compo-nent of a sample will migrate througheach column in a different characteristictime, the chemical signature for aparticular sample consists of migrationtimes for all components in each columnand individual component detectorresponses. Chemometrics can be used tointerpret this complex signature andmaximize the information obtained.

The project combined andexploited Sandia’s strengths in capillaryseparations and parallel data collection(demonstrated previously in develop-ment of a multiple-capillary DNAsequencer) and was augmented byexpertise in molecular recognition andchemometrics. The array instrumentalso serves as a platform for demonstrat-ing concepts for powerful micro-fabricated devices, where highly parallelanalyses can be naturally implemented.A low-cost, compact parallel analysisapproach, enabled by this project, willlead to fieldable devices with capabili-ties that are not possible using currentlaboratory instrumentation. This newcapability will lead to rapid screeningand exacting molecular-level character-ization of complex chemical samplesencountered in environmental sitecharacterization and monitoring. It will

also advance industrial process controlcapabilities, as well as contribute towider DOE and DoD national securitymissions.

The accomplishments of thisyear concentrated on the experimentalaspects of refining the eight-capillaryinstrument, characterizing its perfor-mance, and analyzing real-worldsamples. Instrument refinementemphasized reproducibility (column-to-column and run-to-run) and robust-ness, especially when running real-world samples. Although it is stilldeemed important to the ultimate useof the array instrument, we did not usestatistical analysis in the second yearto the extent anticipated at thebeginning of the project.

Through collaboration with theEnvironmental Sciences Division of theU.S. Environmental ProtectionAgency’s National Exposure ResearchLaboratory, we identified a test sampleconsisting of polycyclic aromatichydrocarbons and nitrogen-containingaromatic compounds. We also ob-tained a number of extracts ofcreosote-contaminated soil, which weexpected to contain compoundspresent in the test sample. Wedesigned an analysis method for thissample using a variety of mobile phasecompositions in the different capillarycolumns in the array and laser-inducedfluorescence detection.

We successfully demonstratedthe instrument performance using thetest sample. With respect to migrationtimes through the column, column-to-column reproducibility was better than5 percent, and the run-to-run repro-ducibility was better than 1 percent.We also successfully ran the real-worldtest sample and identified severaltargeted compounds.

Publications

Other

Anex, D. S. 1997. “Packed-ColumnElectrochromatography: Advances inSingle-Column and Multiple-ColumnTechniques.” Paper presented to theDepartmental Seminar, ChemistryDepartment, Lehigh University, Lehigh,PA, 19 November.

Anex, D. S., D. W. Neyer, H. Zhao, R.Dadoo, R. N. Zare, and C. Yan. 1997.“Selectivity and Efficiency in CapillaryElectrochromatography.” Paperpresented to the 36th Annual EasternAnalytical Symposium, Somerset, NJ,16–21 November.

Anex, D. S., D. W. Neyer, R. N. Zare, andH. Zhao. 1997. “Packed-ColumnElectrochromatography: Advances inSingle-Column and Multiple-ColumnTechniques.” Paper presented to the214th National Meeting of the AmericanChemical Society, Las Vegas, NV, 7–11September.

Zhao, H., D. S. Anex, D. W. Neyer, andR. N. Zare. 1998. “CapillaryElectrochromatography Using Arraysof Packed Columns.” Paper presentedto HPCE ’98: The 11th InternationalSymposium on High-PerformanceCapillary Electrophoresis and RelatedMicroscale Techniques, Orlando, FL, 1–5 February.

Zhao, H., D. W. Neyer, R. N. Zare, and D.S. Anex. 1998. “Analysis of ComplexChemical Samples by Capillary ArrayElectrochromatography.” Paperpresented to HPLC ’98: The 22nd

International Symposium on High-Performance Liquid Phase Separationsand Related Techniques, St. Louis, MO,2–8 May.

3518.060

Designed Synthesis ofControlled DegradativeMaterials

T. A. Ulibarri, D. A. Loy, M. J. Carr, S. H.Scott, R. S. Saunders, J. G. Curro, T. R.Guess, D. R. Wheeler

Sandia will develop polymericmaterials containing weak links fordegradation capabilities that areactivated only by specific keys. Weaklinks are specific functionalities that aresusceptible to degradation and areplaced within the polymer to providereadily cleavable sites. Placement of theweak links can occur randomly or atregular spacing. We will generatematerials for three general applications:


(1) nonlethal deterrents, (2) removableencapsulants, and (3) readily recy-clable/environmentally friendly poly-mers for structural and thin-film applica-tions. In all three applications, a greatbenefit would result from the successfuldevelopment of materials that can becontrollably degraded into smallercomponents, thus providing facileremovability and recyclability. Inaddition, we use commercial–basedpolymer formulations to create anotherclass of readily degradable systems.While these systems may not provide asintricate a key system for degradation,they should provide workable materialsfor large-scale applications in a moretimely manner than the weak-linksystems. In addition, the development ofthese commercial–based polymersystems will provide further insight intouseful degradation pathways that can bebuilt into weak-link polymers. Tounderstand the possible propertychanges manifested due to the weak-linkincorporation, we will combine classicaldensity-functional theory (DFT) withPRISM (Polymer Reference InteractionSite Model) calculations. We willcorrelate the information on polymerstructure and thermodynamic propertiesgenerated through these modeling effortswith experimental mechanical charac-terization. Through this correlation, wewill utilize a feedback loop for thesynthetic effort to optimize the produc-tion of super-slick materials, as well asstructurally similar weak link-containingpolymers suitable for structural and thin-film applications. The ultimate goal ofthis project is to generate families ofdegradable materials that can beapplied anywhere from in nonlethaldeterrent systems to removableencapsulants and recyclable materialsfor the commercial market.

We used new linear andbranched synthesis methods togenerate high-molecular-weight, weaklink-containing polymers. We chemi-cally and mechanically characterizedthe most successful polymer system, aseries of branched polyacrylamide/polyethylene oxide (PEO) copolymers.We achieved lubricity values approach-ing high-molecular-weight PEO with

this copolymer system. We developeda bench-top screening method toassess lubricity using a MINIMATMiniature Materials Tester and customfixturing. Using this testing technique,we identified and characterized acommercial–based system using PEOand ascorbic acid (vitamin C) as apotentially deployable system for nearfuture use. We identified viscositymeasurements of polymer solutions asanother method of evaluating theeffectiveness of degradation pro-cesses. Since we proposed lubricity tobe related to surface tension, weperformed a series of DFT calculationson a polymer chain near a surface toidentify the factors that are importantin controlling surface tension. Surfacetension appears insensitive to bothpolymer density and backbonestiffness; however, cohesive forcesplay a critical role.

3518.120

Adaptive 3-D Sensing

C. Q. Little, D. J. Schmitt, J. J. Carlson, D.E. Small, C. L. Nelson

The purpose of this project is tocreate sensing, reasoning, and controltechnologies that will allow the safe andeffective cooperation of humans andintelligent machines in a variety ofoperations. This will rely heavily onreal-time 3-D sensing and interpretationof the 3-D data. The results of thisresearch will include a new adaptive 3-Dsensing system as well as new researchinto dynamic object modeling, behaviorrecognition, and sensor–based control.The 3-D sensing system will combinetwo existing sensing technologies in anew way to create a site-monitoringsystem that can continuously maintainan accurate 3-D model of the site andreal-time estimates of the shape,location, and motion of humans andmachines. A key strength of this systemwill be the ability to monitor simulta-neous activities, such as several robotsand humans working independently,while also detecting unexpected entryinto the workspace. We will use data

from this sensing system to allowautomated systems, such as robots, tonot only safely co-exist with humanswithin the workspace but to alsocooperate in performing tasks. This willimprove the practicality and efficiencyof many operations by simultaneouslyusing the best skills of both humans andmachines.

We set up a lab with a Fanucrobot, 3-D sensors, and a supervisorysystem to perform experiments inhuman-machine cooperation. The 3-Dsensors include a laser-mappingsystem and a dynamic 3-D motion-detection system. We updated both 3-Dsensor systems to operate on PC/NTplatforms to maintain state-of-the-artcomputing, and improved performanceon both systems. We selected a targetapplication to demonstrate a humanand robot working cooperatively toperform a task. We developed acontrol methodology to implement thecooperative behavior. Several safetysystems are included to ensure safeoperations at all times, including therobot, the supervisor software, anindependent check for illegal entryinto robot workspace, and the acti-vated live-man switch the operatorcarries. We performed image segmen-tation work to aid in object recogni-tion. We developed adaptive sensing todynamically update the 3-D model asnew data are collected.

We gave a human-machinecooperative demonstration with thesystem to the review team and anumber of potential customers. In thisdemonstration, the robot systemperforms an automated task until ahuman walks into an area close to therobot. The robot becomes aware of thehuman through the sensor systemsand tracks the human’s movements.The human can then approach therobot and hand off a part. When thehuman backs away, the robot moves toidentify the part and places it accord-ingly.


3518.070

Mechanistic Models forRadionuclide Desorptionfrom Soils

P. V. Brady, P. Zhang, M. D. Siegel, D. J.Borns

The objective of this project is todevelop and implement a procedure forrelying on natural processes (monitorednatural attenuation [MNA]) to clean upcontaminated soils and groundwaters inthe DOE complex. Sandia believes thatcomplex-wide implementation of thetechnical protocol will result in thesavings of several billion dollars inclean-up costs. The first two years of theproject involved development of thetechnical protocol. In this time wecollaborated with the U.S. Environmen-tal Protection Agency (EPA), the NewMexico Environmental Department(NMED), and several of the nationallabs. Moreover, EM-43 began fundingspin-off efforts.

We completed all experimentalwork on desorption (U-FeOOH; Sr-CaCO3; Cs-Clays; Pb-FeOOH/Basalt) andpublished our book on natural attenua-tion. We developed a field–basedtechnique for demonstrating naturalattenuation of metals and radio-nuclides to regulators. We alsocompleted the first versions of ourtechnical protocol for natural attenua-tion of metals and radionuclides.

Above and beyond our mile-stones, the following happened as aresult of this project:

(1) We were invited to presentthe MNA protocol to HQ DOE(Washington, DC, Las Vegas), the U.S.EPA, the Hanford Site, LawrenceLivermore National Laboratory, andthe European Science Foundation(Crete).

(2) HQ DOE asked us to generatea completely general (includingorganic contaminants) version of theprotocol for review by the NationalAcademy of Sciences (NAS) and

subsequent DOE complex-wideimplementation. The NAS panel isreviewing all of the MNA protocolsbeing used nationwide. Our contribu-tion is the only DOE entry, as we havebeen chosen as the lead lab forcomplex-wide implementation.

(3) We were asked to helpdevelop monitoring guidelines for HQDOE.

(4) We evaluated the trends ofthe EPA’s MNA implementation efforts.

Publications

Refereed

Brady, P. V. 1998. “Natural Attenuationof Inorganic Contaminants.” Paperpresented to the National Academy ofSciences Panel on Intrinsic Remedi-ation, Washington, DC, September.

Brady, P. V. 1998. “Natural Attenuationof Metals and Radionuclides.” Paperpresented to the National StakeholdersForum on Natural Attenuation, SanFrancisco, CA, August.

Brady, P. V., B. P. Spalding, K. M.Krupka, R. D. Waters, P. Zhang, and D.J. Borns. 1998. “Site Screening forMonitored Natural Attenuation withMNAtoolbox.” Sandia TechnicalReport, in review.

Brady, P. V., B. P. Spalding, K. M.Krupka, R. D. Waters, P. Zhang, D. J.Borns, and W. D. Brady. 1998. “SiteScreening and Technical Guidance forMonitored Natural Attenuation at DOESites.” Sandia Technical Report, inreview.

Brady, P. V., D. A. Lucero, and H. W.Papenguth. 1998. “Adsorption/Desorption of Sr from Calcite.” Proc. 8th

Ann. Goldschmidt Conf. (Toulouse,France, 7–12 August).

Eick, M. J., J. D. Peak, P. V. Brady, and J.D. Pesek. 1998. “Kinetics of LeadAdsorption/Desorption on Geothite:Residence Time Effect.” Soil Sci. Soc. ofAmer. (Rancho Mirage, CA, June),accepted.

3518.080

Development of InnovativeCombustion Processes for aDirect-Injection DieselEngine

J. E. Dec, P. C. Miles, D. L. Siebers

The engine for the Partnership forNew Generation Vehicle (PNGV) is oneof the most critical components formeeting the goal of 80 miles per gallon.In FY96, PNGV selected a small-bore,high-speed, direct-injection (HSDI)diesel as the best engine candidate.These engines offer high thermalefficiency, reliability, and compatibilitywith the existing fuel infrastructure andwith projected PNGV vehicle designs.Despite the significant advantages ofthese engines, meeting PNGV’s goals willrequire major technological advancesthat improve their efficiency, powerdensity, and emissions. These advancesinclude improvements in controlling fuelinjection, in-cylinder air motion,combustion, and emissions formation.The current state-of-the-art, small-borediesels (found in Europe) utilize twovalves per cylinder and an angled, off-center, speed-dependent fuel injector.PNGV recently determined that this isnot adequate and that the base engineconfiguration must have four valves percylinder, variable swirl, and a vertical,center-mounted, high-pressure, common-rail fuel injector. In addition, advancedfuel-injection and combustion strategiesare needed. Some promising newtechniques are fuel injection-rate


modulation, water injection, enhanced-swirl combustion chambers, exhaust-gasrecirculation (EGR), and modified fuels.This project will evaluate these tech-nologies, down-select to the mostpromising, develop a research engine,and conduct research to determine theviability of the most promising technolo-gies.

We completed installation andtesting of the engine, but the engineand laboratory infrastructure are notyet operational. We investigated theignition delay and locations in theoptical research engine using pressureanalysis and chemiluminescentimaging. We found that ignition delaymeasurements based on combustionluminosity and natural chemilumines-cence are more sensitive than pressuremeasurements. We completed corre-sponding measurements, employingsplit-injection strategies.

We expanded investigations offuel-water emulsions for simulta-neously reducing the production ofboth NOx and soot. The expanded datasets include three emulsion concentra-tions and parametric variations ofengine operating conditions (top deadcenter [TDC] temperature, TDCdensity, and fuel loading) for someemulsion mixtures. We also imple-mented an additional diagnosticcapability to quantitatively measurethe changes in in-cylinder soot levels.This diagnostic involves a line-of-sight(LOS) extinction measurement throughthe operating diesel engine, whichallows more rapid quantitative

measurements of the relative sootconcentration than previous laser-induced incandescence (LII) imagingmeasurements. We conducted severaltests:

(1) We measured the straight fueland an emulsion with 10% water in thefuel with the new diagnostic. For thebase condition, the LOS extinctionmeasurement showed that the emul-sion reduced the in-cylinder sootlevels by about a factor of two, whichis in good agreement with previousmeasurements using LII imagingreported last year.

(2) We made parametric varia-tions to the TDC temperature, TDCdensity, and fuel loading for both thestraight fuel and the 10% emulsion. Forboth fuels, soot levels changedconsiderably across the parameterspace. However, the 10% emulsionconsistently produced lower sootlevels for all conditions (approximatelya factor of two lower).

(3) We increased the waterconcentration in the emulsion to 20%.This resulted in a further reduction ofin-cylinder soot levels. Although thereduction varied with operatingconditions, it was on the order of two-thirds of the level with the 10%emulsion, or about one-third of thesoot level for the straight fuel.

(4) We further increased thewater concentration to 30%. Thisproduced even lower soot levels, butthe drop was less significant, beingonly about 15% less than for the 20%emulsion. This indicates that we were

reaching a point beyond whichadditional water would not offerfurther improvement.

These investigations show thatwater added to diesel combustion hasa strong potential for reducing in-cylinder soot levels. Since wateraddition is well known to reduce NOx

emissions through its cooling effect onthe combustion process, these studiesshow that fuel-water emulsions or dualfuel-water injectors have a strongpotential for reducing diesel-engineemissions.

We presented results from theresearch and implications for designparameters to the U.S. engine manufac-turers through three meetings associ-ated with the DOE-funded CooperativeResearch and Development Agreement(CRADA).

Publications

Other

Canaan, R. E., and J. E. Dec. 1997. “TheEffect of Fuel-Water Emulsions on In-Cylinder Soot Levels.” Paper presentedto the Diesel Combustion ReviewMeeting, Southfield, MI, 19 August.

Dec, J. E. 1998. “Report on the Line-of-Sight Diagnostic and Results withDiesel Fuel.” Paper presented to theDiesel Combustion Review Meeting,Dearborn, MI, 12 May.

Miles, P. C. 1998. “Small-Bore DieselUpdate.” Paper presented to the DieselCombustion Review Meeting,Dearborn, MI, 13 May.


3518.090

Hydrogen Production forFuel Cells by SelectiveDehydrogenation of Alkanesin Catalytic MembraneReactors

T. J. Gardner, C. J. Brinker, A. G. Sault

Hydrogen-powered polymerelectrolyte membrane (PEM) fuel cells,fueled by on-board H2 generation fromliquid fuels, represent an importanttechnology for all-electric or hybrid-electric vehicles. Much current effort hasbeen devoted to the use of steam-reforming or partial oxidation of liquidfuels for on-board H2 generation, butthese technologies generate largeamounts of CO and CO2, which canpoison PEM fuel cells. Sandia willdevelop a catalytic membrane reactorsystem for the generation of pure H2 viaselective dehydrogenation of liquidfuels. We will achieve separation of H2

from hydrocarbons and other potentialcontaminants (e.g., CO, CO2, etc.) bymodifying commercial alumina mem-brane tubes with size-selectivemicroporous ceramic membranes. Wewill also use hydrous metal oxide(HMO)–based ion-exchanger technologyto prepare novel bulk and coateddehydrogenation catalysts. These HMOmaterials are superior to conventionaloxide supports, such as titania andsilica, in that they can be synthesized tocontain high concentrations of sodiumions, which can be ion-exchanged withtransition-metal ions that are catalyti-cally active for selective dehydrogena-tion. By using HMO–based catalysts, wehope to increase conversions achiev-able with a conventional catalyst insidethe membrane tube. This overall schemeoffers a potential method for increasingH2 production rates without increasingreactor size, an important considerationfor transportation applications or forremote electricity generation for civilianor military applications.

Previous membrane reactorstudies identified a problem with low

H2 generation rates due to insufficientcatalyst activity and selectivitycombined with significant catalystdeactivation over time. AlthoughHMO–based catalyst developmentidentified Cr/silica-doped hydroustitanium oxide (HTO:Si) catalysts withhigh heptane dehydrocyclizationactivity on an active metal basis,increased metal loading did not resultin the required improvement incatalyst activity or selectivity relativeto commercial Cr–based catalyst (7.5wt.% Cr/Al2O3). We also investigatedPt (and Pt-Sn or Pt-Re/HTO:Si)HTO:Sicatalysts as an alternative to the Cr–based catalysts. We observed signifi-cant catalyst activity for the lowermetal loading (~ 1 wt.% metal) Pt/HTO:Si catalysts; however, we encoun-tered significant catalyst deactivationproblems, and overall catalyst perfor-mance again fell short of the resultsobtained for the commercial 7.5 wt.%Cr/Al2O3 catalyst. Our catalystdevelopment efforts were unable toidentify an improved catalytic mem-brane reactor catalyst material relativeto the commercial Cr/Al2O3 catalyst.

We pursued microporousceramic membrane development inparallel with the catalyst developmentefforts. We developed a range of SiO2–based membranes that offer thepromise of superior H2 separationperformance combined with increasedH2 permeance. Various synthesisroutes can be used individually or incombination to fabricate thesemembranes, including surfacederivatization, fugitive organictemplating, and surfactant templating.This past year, efforts concentrated onmembrane fabrication via surfactanttemplating combined with surfacederivatization techniques.

We developed a new process toform a highly selective membranecapable of discriminating H2 (2.893)from N2 (3.643), CO2 (3.33), CH4 (3.83),and CO (3.763) for fuel-cell applica-tions. In practice, membrane formationis very sensitive to the quality of thesupport surface and the film-coating

environment. Therefore, we firstdeposited a C6-surfactant(triethylhexylammonium bromide)-templated silica intermediate layer ontop of a commercial g-alumina supportto both improve surface finish andprevent the subsequently depositedsol from penetrating into the support.Second, we dip-coated membranesunder class 100 clean-room conditionsto avoid dust contamination andvacuum-calcined them to promotefurther pore shrinkage. The vacuumcalcination procedure apparently alsoresulted in the decomposition ofsurface ethoxy groups; therefore, ahydrophobic inner pore surface wasformed to avoid water attack. This newprocedure resulted in both high fluxand selectivity for the asymmetricmembranes with gradual changes ofpore size from 503 (g-alumina supportlayer) to 10–123 (surfactant-templatedsilica sublayer), and then to 3–43

(ultra-microporous silica top-layer).For a pure gas-permeation experiment,H2 flux reached 1x10-3 cm3 (STP)/s/cm2/cmHg with a H2/CO selectivity of 200.The membrane also showed a high H2

flux (5.4 x 10-4 cm3 (STP)/s/cm2/cmHg)at 80° C in the separation of hydrogenfrom a simulated fuel-cell feed stream(compositions: 33.98% N2, 15.00% CO2,0.997% CO, balance H2) as evidencedby a high concentration of hydrogen(92 mol.%) recovered in the permeateside stream. The CO concentration(CO is a fuel-cell poison) in thepermeate was 193 ppm in a one-throughput feed condition.

Publications

Refereed

Lu, Y., G. Cao, R. P. Kale, S. Prabakar, G.P. Lopez, and C. J. Brinker. 1998.“Microporous Silica Prepared byOrganic Templating: RelationshipBetween the Molecular Template andPore Structure.” Chemistry of Mater.,accepted.

Lu, Y., R. Ganguli, C. A. Drewien, M. T.Anderson, C. J. Brinker, W. Gong, Y.


Guo, H. Soyez, B. Dunn, M. H. Huang,and J. I. Zink. 1997. “ContinuousFormation of Supported Cubic andHexagonal Mesoporous Films by Sol-Gel Dip Coating.” Nature 389 (25September): 364–368.

Tsai, A. C., and C. J. Brinker. 1998.“Silica Gas Separation MembranesPrepared with Surfactant-TemplatedSublayers.” Proc. 5th Internat. Conf. onInorg. Membranes 1 (Nagoya, Japan,22–26 June): 180–183.

3518.110

Hybrid Vehicle EngineDevelopment

P. Van Blarigan, K. L. Wu, N. J. Paradiso,Jr., S. S. Goldsborough, J. Wu, D. V.Zanini

An attractive approach to increas-ing the fuel efficiency and lowering theemissions of motor vehicles is the hybriddrive train. In the series-type hybrid, theengine drives only an electrical genera-tor; electric motors power the drivewheels. With electrical energy storagethis allows the engine to run at constantspeed and power with the engine atmaximum efficiency at all times. Theconcept of a variable compression ratiofree-piston internal-combustion electricalgenerator subsidizes mechanicalsimplicity with electronic sophistication,resulting in a one-moving-part engine.The one moving part is a double-endedpiston that oscillates in a cylinder that isclosed on each end. Ports are placed inthe cylinder walls to allow venting of theburned gases and introduction of a freshfuel/air mixture in the two-stroke-cyclescavenging mode. Electrical output isgenerated directly from piston motion byfixing magnets on the piston, whichmoves through magnet steel andgenerates a time-varying current in fixedcoils. Ignition is by compression heatingof the homogeneous fuel/air charge,with timing accomplished by electroni-cally controlling the compression ratio.

Several advantages ensue: (1)The compression is developed inertiallyand is not fixed. Thus, it can be con-trolled by kinetic energy management bythe engine controller. (2) Homogeneouscharge compression ignition (HCCI) cancombust lean mixtures of hydrocarbonfuels, impossible with spark ignition,greatly reducing NOx production. (3) Allmoving engine parts except the pistonand inlet blower are eliminated. (4)Ideal Otto cycle performance isapproached more closely than in aconventional engine due to rapidcombustion and reduced heat transfer, aconsequence of the velocity profile ofthe free piston. Coupled with the high-compression ratio of compressionignition, we anticipate that this enginewill produce electricity with 40% lessfuel than existing low-emissions designs.The goal of this project is to design,build, and demonstrate the performanceof a prototype engine.

(1) We demonstrated substantialimprovements in the efficiency of theHCCI combustion system over conven-tional combustion processes throughthe use of a free-piston, single-stroke,combustion experiment burninghydrogen, propane, natural gas,methanol, and dimethyl ether, andthrough computational investigationsof the same. We noted the followingfindings:

(a) High-compression ratio (30:1)can be achieved at the time of combus-tion.

(b) A high rate of combustion forpropane, natural gas, hydrogen, andmethanol approaches that of constantvolume combustion.

(c) While NOx emissions doincrease with increasing compressionratio, they can be controlled bydecreasing the equivalence ratio sincethe problem of sparks igniting ultra-lean mixtures is not a concern in theHCCI combustion process.

(d) The autoignition characteris-tics of the fuels tested varied widely.The data showed that some fuels reactin two stages and not completely.Generally higher initial temperatures

and higher compression ratios burnmore of these fuels. An additionalfactor that may affect the burningprocess, especially for the two-stagefuels, is the rate of piston oscillation.This variable should be investigated inthe future.

(2) We tested the performancepotential of hydrogen, propane,natural gas, methanol, unleadedgasoline, dimethyl ether, ethanol,isooctane, pentane, hexane, andheptane.

(3) We established importantcriteria regarding the design andconstruction of the linear alternatorcomponents of the electrical genera-tor.

(4) We constructed a full-scalelinear alternator tester.

(5) We developed a preliminarydesign for a linear alternator.

Publications

Refereed

Goldsborough, S. S. 1998. “A NumericalStudy of a Free-Piston, Internal-Combustion Engine.” J. Soc. of Automo-tive Engin. (Spring 1999).

Van Blarigan, P. 1998. “AdvancedHydrogen-Fueled Internal-CombustionEngines.” Energy and Fuels (January).

Van Blarigan, P. 1998. “A Hydrogen-Fueled Internal-Combustion EngineDesigned for Single-Speed/-PowerOperation.” Internat. Assoc. H2 Energy23 (7) (May): 603–609.

Van Blarigan, P., S. Goldsborough, andN. Paradiso. 1998. “HomogeneousCharge Compression Ignition with aFree Piston: A New Approach to IdealOtto Cycle Performance.” J. Soc.Automotive Engin. (Spring 1999).

Other

Goldsborough, S. S. 1998. “A NumericalInvestigation of a Two-Stroke Cycle,Hydrogen-Fueled, Free-Piston Internal-Combustion Engine.” MSME Thesis,Colorado State University, Fort Collins,CO (Summer).


3518.130

Aqueous Organic Sensor

D. S. Blair, W. C. Sweatt, M. J. Kelly, K. J.Kasunic, S. A. Kemme

Currently regulated drinking waterstandards dictate that concentrations ofspecific chemical compounds known asaromatic hydrocarbons not exceed 5parts per billion (ppb). However,detection and quantitation of com-pounds in water at these concentrationsare extremely complex and are typicallyperformed using purge-and-trap analyti-cal methods. This approach hasinherently long analysis times and, forfield-deployable instrumentation, highdevice maintenance requirements andequipment failure rates. Sandia willbuild a new, unique sensor that has thepotential to measure aromatic hydrocar-bons in aqueous solutions at ppbconcentrations. This technology usesspectroelectrochemistry as its fundamen-tal transduction mechanism. Significantadvances have been made in the pasttwo decades in studies of metal/solutioninterfaces by spectroelectrochemicalmethods. Here, the detection andquantitation of analytes in watertypically rely on monitoring the electro-chemical generation of an opticallydetectable compound. However, instrongly protonating solutions (e.g.,water), detection of a strongly absorbingionic species, such as the benzo anion,can be problematic. This work recog-nizes and addresses that problem bymodulating the electrode potential suchthat protonation does not occur on thetime scale of the spectroelectrochemicalmeasurement. The spectroscopicmethod that we are combining with

electrochemistry is known as GratingLight Reflection Spectroscopy (GLRS).A new, emerging technology, itnoninvasively provides informationabout the dielectric function (i.e., boththe real and imaginary parts of therefractive index) of the sample. This canthen be translated into quantitativechemical information. The goal of thisresearch is to produce a field-deployableaqueous organic sensor that is compact,rugged, and simple to use.

We designed, fabricated, andassembled all components of theoptical spectroscopy system and thespectroelectrochemical cell. We theninitiated the evaluation of thelaboratory-prototype GLRS aqueoussensor. The key components of theGLRS experiment are the grating, thespectroelectrochemical cell, and theoptical spectroscopy system. Weevaluated gratings with 1.6-micronchromium metal lines deposited onglass. The spectroelectrochemical celluses the metallized grating lines as theworking electrode and incorporates aplatinum mesh counter electrode anda silver wire quasi-reference electrode.Finally, we designed and fabricatedtwo optical spectroscopy systems. Thefirst system exploits the wavelengthdependence of the angle of diffractedlight from the grating. The secondGLRS system scans the light sourceacross the spectral singularity via theangle of the incident light. Our experi-ments to date show that the secondsystem provides tremendous improve-ments in signal-to-noise (S/N) ratiocompared to the first system. Further,it reduces cost, complexity, and size,all of which are extremely importantwhen it comes to turning the labora-

tory prototype into a rugged, fieldablesensor. This system will work with amedium-power (5–10 mW), single-mode, frequency-stabilized lasersource, which allows interferometricmeans for aligning the grating. Thiswill further improve the quality of theGLRS data. The second system issimple and elegant, as are a number ofplanned improvements, all of whichare projected to provide quantum,order-of-magnitude leaps in thesensitivity and detection limits of theGLRS aqueous organic sensor.

3518.140

Designed Ionophores forLiquid-Membrane Separationand Extraction of Metal Ions

J. A. Shelnutt, G. E. Bujewski, J. E.Miller, A. Martino

Sandia is developing new materi-als and processes for metal-ion separa-tion and extraction based on selectivetransport of ions across membranes.Using molecular simulations, we aredesigning a new group of porphyrin–based ionophores (molecular ion-carriers) for selectivity in complexingand transporting metal ions by control-ling basicity, shape, and size of theionophores. Using the initial designresults, we will design sandwich/clamshell ionophores specifically forextraction of heavy metals and radionu-clides. We will synthesize and testpromising ionophores for application intwo different membrane systems. Thefirst is a supported liquid membrane thatseparates two liquid phases—one


containing waste and the other a liquidfrom which the specified metal ions areextracted. The ionophores selectivelytransport a specified metal ion throughthe intervening liquid layer to give apure solution of the metal ion that iseasily concentrated. In the second, weare developing metal-ion transport andentrapment in surfactant vesicles usingthe new ionophores. Separation of thevesicles leaves a pure metal-ionsolution. These extraction technologiesoffer convenient new means of separa-tion and extraction for processing Mo-99,decontamination and decommissioning,radioactive-waste remediation, andheavy-metal waste stream treatment.The initial focus area is high-level wastetank remediation of heat and gammaemitters (137Cs and 90Sr), long-livedradionuclides (99Tc), and other metalions contained in high- and low-levelwaste. Ion-extraction technologies usingdesigned ionophores lead to increasedsustainability and lower cost andcomplexity of manufacturing processes.Adaptation to pump/treat methods foruse at sites such as the White SandsExperimental Test Station and Tuba Cityis also considered. The technology isdifferentiated from other efforts (1) byusing molecular simulation to engineerhigh-performance ionophores, (2) byapplying Sandia’s recognized expertisein computer-aided molecular design ofunexplored ionophore types, and (3) byusing two new membrane systems.

We synthesized more than tenpotential free-base porphyrin iono-phores and evaluated them for theirion-transport properties. We used bothsupported-liquid membranes and bulk-liquid membranes in the transport

testing protocols. The ionophoresincluded some porphyrins that arehighly nonplanar and thereforeexpected to be good carriers. Theionophores tested exhibited a widerange of ion-transfer rates, varyingfrom almost no transport to some thatare comparable to or better thancurrently used ion carriers. Asexpected, the planar porphyrins arepoor carriers, consistent with ourinitial hypothesis and also our molecu-lar simulations of the porphyrin-ioncomplexes. We suspected that out-of-plane saddling of the porphyrin wouldbe necessary to expose the lone pairson the nitrogens so they could interactwith the ion. The perceived require-ment for saddling of the porphyrinstructure turned out to be not soimportant, however. The reason is thatmany nonplanar free-base porphyrinsare highly flexible and thus easilybecome saddled due to H-bonding andionic interactions with the porphyrincore. This unexpected outcomeeffectively broadens the base ofpossible porphyrins suitable forcomputer design and synthesis as newionophores. We structurally character-ized many of the designed ionophoreswith UV-visible absorption, nuclearmagnetic resonance (NMR), x-raycrystallography, and resonance Ramanspectroscopy. We found relationshipsbetween porphyrin conformationaland electronic properties and theirion-transport rates and will incorpo-rate this information into the molecu-lar design procedures. For example,the presence of electron-withdrawingsubstituents on the porphyrin isdesirable because they apparently

increase ion-transport rates. Becauseof the successes in liquid-membraneextraction methods, we focused lesson the vesicle-extraction methods.

Publications

Refereed

Kadish, K. M., E. Van Caemelbecke, F. DSouza, M. Lin, D. J. Nurco, C. J.Medforth, T. P. Forsyth, B. Krattinger,K. M. Smith, S. Fukuzumi, I. Nakanishi,and J. A. Shelnutt. 1998. “FluorinatedDodecaphenylporphyrins: Syntheticand Electrochemical Studies Includingthe First Evidence of IntramolecularElectron Transfer Between an Fe(II)Porphyrin p-Anion Radical and an Fe(I)Porphyrin.” Inorg. Chem., submitted.

Other

Qiu, Y., A. Martino, J. Kawola, and J. A.Shelnutt. 1998. “Porphyrins as Iono-phores for Liquid-Membrane Metal IonExtraction.” Abstracts of Papers of theAmer. Chem. Soc. 215 (Dallas, TX, 29March): 228.


3518.150

An Electromagnetic ImagingSystem for EnvironmentalSite Reconnaissance

G. M. Loubriel, G. J. Denison, A. G.Baca, G. L. Peace

The advantages of time-domain,ultra-wideband transmitters for ground-penetrating radar (GPR) are many andwell known: GPR has the potential forhigh-resolution subsurface imagingunmatched by any other subsurfacesensing method. With GPR there arelarge contrasts between contaminatedand noncontaminated regions. Thus GPRmay detect man-made buried objectsand detect and define the extent ofcontaminated soil. This project seeks todevelop a GPR system that can beutilized for environmental site recon-naissance and, in particular, for (1)detecting disrupted soil layers wherethere is a potential for buried waste, (2)finding buried metallic objects such as55-gallon drums at depths of up to 10 m(and other man-made objects at variousdepths), and (3) detecting contaminatedsoil. Because of the simplicity of thetime-domain technique, the system willbe fast enough to evaluate extensiveland areas that may be contaminated.

The primary disadvantages of GPR havebeen low penetration depth and lowsignal-to-clutter. This project is designedto minimize both of these problems.Sandia will augment the penetrationdepth by using (1) high-peak-power,high-repetition-rate operation for highaverage power, (2) low center frequen-cies that better penetrate the ground,and (3) short-duration impulses. Thelatter allow for the use of low platformsthat increase the power on targetrelative to a high flying platform (due tothe R4 term in the radar equation, whereR is the range to the target). We mini-mize clutter by time-gating the surfaceclutter return and using low frequencies(since natural objects are smaller thanthe wavelengths used here, and theircross-section is smaller than for higher-frequency systems). The factor thatmakes this work unique is that we willutilize direct time-domain radar at lowfrequency and high average power.

We accomplished our majorobjectives: to model the problem,build an impulse transmitter for GPRfield tests, and design a variable centerfrequency transmitter that we willbuild in the upcoming year. We alsoadded a new task, to measure switchjitter and longevity. Three majorefforts were required to meet the FY98objectives: to theoretically model

ground penetration to guide thetransmitter development (carried outin collaboration with Duke University),perform pulser construction at fixedfrequency (but higher than attemptedpreviously), design a variable fre-quency system, and develop a switch.We started tests of the system intransmit/receive mode and of reflec-tion from targets in air. The biggestchallenge this year was to increase theoperating frequency of the transmitter;this forced us to design and testdifferent pulser designs that werevariants of the original design. Becauseof the introduction of the new pulserdesigns, we wanted to assess the effectof the different designs on switchlongevity. We added a new task, tomeasure switch jitter and longevitywith the original pulser design.

Publications

Other

Loubriel, G. M., F. J. Zutavern, A. Mar,A. G. Baca, H. P. Hjalmarson, M. W.O’Malley, G. J. Denison, W. D. Helgeson,D. J. Brown, R. L. Thornton, and R. M.Donaldson. 1998. “High-Gain GaAsPhotoconductive SemiconductorSwitches: Switch Longevity.” Proc. 23rd

Internat. Power Modulator Symp.








RISK &

RELIABILITY

Sandia’s primary mission of stockpile stewardshiprequires a superior understanding of how to managethe risks and to ensure the reliability of nuclearweapons and waste and other high-value assets. Thisarea sponsors development of methods and tools aswell as new components and systems to support theSandia mission. The Risk and Reliability investment areaencompasses four categories of study: (1) predictingrisk and reliability for systems and components; (2)studying how products and technologies age;(3) developing methods, techniques, and tools toevaluate how design changes affect reliability; and(4) developing approaches and tools to detectpotential problems and to maintain equipment andsystems. Traditional reliability methods depend on thecollection of a large number of samples orobservations to characterize the existing conditionof the weapons stockpile. A major objective of thisresearch is to develop mathematical techniques andcomputer analysis tools to anticipate stockpileproblems before they become critical issues. Thisapproach permits a more efficient use of limited testresources and also assists design engineers inplanning for new materials and manufacturingtechniques. This is particularly important as Sandiamoves toward commercial off-the-shelf replacementcomponents. This research focused on developing mathema-tical methods for incorporating uncertainty intraditional modeling, in particular, the advancedphenomenological modeling and simulationtechniques used to characterize the physics of theunderlying failure processes. The overall objectiveof the research is to statistically characterize howthe performance characterist ics of thesystem change as a function of system age. We are currently using the analysis tools devel-oped under this project to characterize the reliabilityof the national electrical power grid. These newreliability and uncertainty analysis methods couldeasily be integrated into the Product RealizationEnvironment (PRE) framework. The PRE frameworkhas been designed and developed in support ofSandia’s Product Realization backbone with the goalof providing new and improved information tools tohelp reduce the time and cost for realizing nuclearweapons components.





3520.220

Integrated Approach toDevelopMicroelectromechanical(MEMS) Reliability Tools

D. M. Tanner, L. W. Irwin, N. F. Smith, K.A. Peterson, W. P. Eaton, P. Tangyunyong

The burgeoning new technology ofmicroelectromechanical systems(MEMS) shows great promise in theweapons arena. We can now conceiveof microgyros, microsurety systems, andmicronavigators that are extremelysmall and inexpensive. Do we want touse this new technology in criticalapplications such as nuclear weapons?The answer to this question drives us tounderstand the reliability and presentlyunknown failure mechanisms of MEMS.

Sandia assembled an interdiscipli-nary team that integrated the individualresearch areas of failure and perfor-mance analysis, reliability characteriza-tion, and wafer-level reliability. Thiswork has not been attempted before andwill produce the knowledge that isessential for maintaining world-classMEMS status at Sandia. The overallgoals of this work are (1) to performstatistical characterization, (2) toidentify failure modes, (3) to developreliability test structures, (4) to developreliability models that account fortemperature, humidity, cycles, operatingspeed, etc., and (5) to develop failureanalysis tools for MEMS.

In meeting our goal of statisticalcharacterization, we successfully usedSHiMMeR (Sandia High-VolumeMeasurement of MicromachineReliability) to acquire data on micro-engines driving loads at differentstress frequencies. We observed wearas the main failure mode in thisexperiment. We developed a reliability

model that predicts the failure as afunction of number of revolutions andstress frequency. We based the modelon the fundamental physics of wearcoupled to mechanical resonanceeffects. We effectively used the basicwear model to describe failures indifferent MEMS devices.

Since many of the criticalapplications for MEMS require that thepart lie dormant, then work whenneeded, we started several storage-lifeexperiments. The experiments areongoing; preliminary results indicate afailure of 10% in 8 months, implyingthat this is an area that needs furtherinvestigation.

We built up an incredible amountof infrastructure needed to performthe reliability experiments. We nowhave a super microdriver computercode that can drive any MEMS device;an environmentally controlledchamber to perform experiments;automated wafer-probing capability;and SHiMMeR Lite, a smaller data-acquisition station that allows smallfast experiments to follow up onpromising ideas.

To facilitate the understanding offundamental failure modes, wedesigned several reliability teststructures to measure friction andwear of rubbing surfaces and arecurrently fabricating them.

Publications

Refereed

Tanner, D. M., W. M. Miller, K. A.Peterson, M. T. Dugger, W. P. Eaton, L.W. Irwin, D. C. Senft, N. F. Smith, P.Tangyunyong, and S. L. Miller. 1998.“Frequency Dependence of theLifetime of a Surface-MicromachinedMicroengine Driving a Load.” J.Microelectron. Reliability, submitted.SAND98-1968J.

Other

Eaton, W. P., N. F. Smith, L. Irwin, D. M.Tanner, J. J. Allen, S. L. Miller, and W.M. Miller. 1998. “CharacterizationTechniques for Surface-MicromachinedMicroengines.” Proc. SPIE, 1998 Symp.Micromachining and Microfabrication3514 (Santa Clara, CA, September):171–178.

Miller, S. L., M. S. Rodgers, G. LaVigne,J. J. Sniegowski, P. Clews, D. M. Tanner,and K. A. Peterson. 1998. “FailureModes in Surface-MicromachinedMicroelectromechanical Actuators.”1998 Proc. IEEE Internat. ReliabilityPhys. Symp. (Reno, NV, March): 17–25.

Peterson, K. A., P. Tangyunyong, and A.A. Pimentel. 1998. “Failure Analysis of aSurface-Micromachined Microengine.”Proc. SPIE, 1998 Symp. onMicromachining and Microfabrication3512 (Santa Clara, CA, September):190–200.

Tanner, D. M. 1998. “Reliability ofSurface-Micromachined MEMS Actua-tors.” Paper to be presented to theIEEE 22nd International Conference onMicroelectronics (Invited keynote),Nis, Yugoslavia, 19–22 September 1999.

Tanner, D. M., L. W. Irwin, W. P. Eaton,N. F. Smith, K. A. Peterson, and W. M.Miller. 1998. “Linkage Design Effect onthe Reliability of Surface-Micromachined Microengines Drivingan Inertial Load.” Proc. SPIE, 1998Symp. Micromachining andMicrofabrication 3512 (Santa Clara, CA,September): 215–226.

Tanner, D. M., W. M. Miller, W. P. Eaton,L. W. Irwin, K. A. Peterson, M. T.Dugger, D. C. Senft, N. F. Smith, P.Tangyunyong, and S. L. Miller. 1998.“The Effect of Frequency on theLifetime of a Surface-MicromachinedMicroengine Driving a Load.” 1998 IEEEProc. Internat. Reliability Phys. Symp.(Reno, NV, March): 26–35.


3520.210

Reliability Degradation Dueto Stockpile Aging

D. G. Robinson, P. C. Butler

This research involves thedevelopment of a new method forcharacterizing the reliability of systemswith the time-dependent failure modesassociated with stockpile aging. Currentstockpile reliability assessment tech-niques do not consider time-dependentdegradation of components, but insteadview system operation as a go/no-gosituation. Fundamental to the approachbeing investigated here is the hypothesisthat, by monitoring system performancethrough testing in conjunction withscience–based modeling, it is possible tocharacterize time-dependent changes inmaterial properties and identify aging-related problems earlier, with fewer testresources. This requires the coupling ofthe actual physics associated withdegradation with uncertainties inmaterial properties, storage environ-ment, etc. The potential applications tobe addressed involve stress-voiding ofelectronic interconnects, thermo-mechanical fatigue of integrated circuit(IC) packaging, and the corrosion ofelectronic components, all of which weidentified as high-consequence, high-likelihood stockpile issues. Of particularconcern was the need to assess thereliability of submicron interconnectscommon in ICs as they are affected by afailure mechanism known as stress-voiding. Stress gradients in the metalli-zation are caused by a mismatch ofthermal expansion coefficients. Thesegradients are known to drive masstransport and void growth. The originalthrust of this research was to construct areliability model for this process.However, as this research progressed,various design and analysis groupsidentified the potential of this newapproach, and other applications wereinvestigated.

A number of probabilisticmethods could potentially be applied,

at least in part, to this problem. Theemphasis of the research was on thedocumentation and software coding ofthe existing techniques, applying thesetechniques to existing stockpileproblems, and identifying weakness inthe existing probability and reliabilitymethods. We applied the methods toprovide insight into not only thestress-voiding problem, but also thetime-dependent electronic componentfailure due to atmospheric corrosion.As we investigated each of the tech-niques, we coded a software routine,incorporated it into a general uncer-tainty analysis package (CRAX), andevaluated it relative to computationalefficiency and accuracy. We willcomplete a survey of the predominantprobabilistic methods. This documentdiscusses each method in technicaldetail and is applied to a simpleworking example. (The exampleinvolves the stress-voiding of elec-tronic interconnects.) We also presenta summary of the computationalrequirements along with the technicallimitations of each approach.

Publications

Refereed

Mahadevan, S., D. Robinson, and Z.Guo. 1998. “Probabilistic Analysis ofStress-Voiding Problem in AluminumInterconnection Lines.” IEEE Trans. onReliability, submitted.

Robinson, D., S. Mahadevan, and Z.Guo. 1998. “Time-Dependent Stress-Voiding Reliability of ElectronicCircuits.” Proc. 3rd Internat. Conf. onComputational Stochastic Mechanics 1(Santorini, Greece, 14–17 June): 100–124.

Other

Robinson, D. G. 1998. “A Survey ofProbabilistic Methods Used in Reliabil-ity and Uncertainty Analysis: Analyti-cal Techniques I.” Sandia TechnicalReport SAND98-1189 (June). SandiaNational Laboratories, Albuquerque,NM.

3520.230

Precursors to Failure ofOxides and Metal Lines inCMOS Technology

W. F. Filter, W. L. Larson, L. W. Irwin, S.H. Yazzie

Sandia originally proposed aparadigm shift away from statisticalreliability toward individual partreliability. Historically, reliabilityengineers conducted long-term, expen-sive, large-sample lifetime tests topredict the reliability of electricalcomponents. Sandia and the integratedcircuit (IC) industry have since imple-mented a model–based methodologythat uses test structures to predict thereliability of components as a group.However, both of these strategies treatcomponent reliability statistically andare valid only for large numbers ofparts. This is not a complete methodol-ogy in a world of low-volume productionand use. We will use electrical-failureprecursors to tell when individualdevices are going to catastrophicallyfail.

An electrical-failure precursor isany electrical signal that gives warningof a component’s impending demise.People are already familiar with otherprecursors in their everyday lives: thecreak of a wooden board about to break,or the cracks that appear in an ice-covered pond just before it gives way.Likewise, electrical precursor signalsfrom failing microelectronics wouldprovide similar warnings of failure, ifonly we were able to recognize andmodel them. This would result in majorbenefits: (1) ability to characterizeindividual component reliability, therebyallowing small numbers of parts to be


used, (2) ability to use components untilnear the end of life with sufficientwarning to procure replacements (suchas through block upgrades), and (3)ability to automate reliability surveil-lance, possibly resulting in componentsthat monitor themselves or ICs thatmonitor system or subsystem reliability.In a world of increasing lifetime expecta-tions from a smaller stockpile, theunderstanding and implementation of ascience–based reliability precursordetection and characterization schememight allow us to have longer-lived partswith better-characterized reliability.Therefore, our overall goal is to gain anunderstanding of electrical-failureprecursors for insulators and conductorsin ICs, to model these precursors, and tocreate a method for predicting failuretimes based on these models.

After redirection by the reviewpanel, we focused our investigation ofelectrical precursor signals in ICs onelectromigration experiments on metalconductors; we dropped the investiga-tion of dielectric breakdown. Program-matically, this redirection occurredbecause of a perceived greaterimportance of metal breakdown inweapons systems over dielectricbreakdown. Technically, the dielectricbreakdown studies that were droppedmay have been the more promising ofthe two, being based on a firmertheoretical and modeling foundation.

In performing newelectromigration testing, we discov-ered that our current electromigrationtesting methodology, termed isother-mal, probably created breakdown thatwe would not expect to occur innormal use. This meant that theprecursor signals observed in theseexperiments would not necessarily

manifest themselves under normalwearout, leaving the quantification andinterpretation of the precursors indoubt. The isothermal test method isbased on joule-heating a metal teststripe with a high-current density andadjusting the current to a target stresstemperature until catastrophic failure.The problem with this method is that,when a metal stripe develops a void asfailure occurs, the temperature of thenonvoided section of the stripe candrop significantly in an unknown way.Temperature is a key parameter in thistesting, yet control of temperature waslost at this point. A simpler, lowconstant-current stress test, wheretemperature was not determined bythe stripe current, was put in place toget rid of the uncertainty.

We observed that precursorsignals still occurred at a low-stresscurrent; however, the failure signa-tures did not occur at the timespredicted by extrapolating the highlyaccelerated isothermal stress datausing a well-established time-to-failureequation (Black’s equation). Thisdiscovery caused us to question andreview our department’s long-established electromigration testingmethods and procedures. The low-current testing performed as part ofthis year’s activities resulted inprecursor signatures occurring veryquickly. Warning times were veryshort, less than 5% of the remainingtest-stripe lifetime. Data acquired theprevious year using the isothermalmethod had resulted in precursors atapproximately 10%–15% of remainingstripe lifetime. Obviously, the time ofoccurrence of the precursor dependedon the test conditions to the extent ofobscuring any fundamental physical

triggering, and any study of what thebest test methodology should bewould go far beyond the work andbudget established for this project.

This year we also questionedwhether or not the standardelectromigration test equipment usedto detect precursor signals hadsufficient bandwidth. To answer thisquestion, and to analyze precursorcharacteristics in the frequencydomain, we prototyped a higher-bandwidth test system to capture andmeasure the electrical signatures. Datafrom this test system indicatedevidence of faster precursor spikesthat could perhaps be used to under-stand the basic physics of precursors.However, understanding the basicphysics is well beyond the scope of thecurrent project. A much less noisyhigh-bandwidth test system than theprototype needs to be built. With thisaccomplished and a careful correlationof precursor events to transmissionelectron microscopy (TEM) analysis ofchanges in the test-stripe microstruc-ture, we may discover a physics–basedunderstanding of these electricalprecursors caused by electro-migration. In the original provision forthis project, we lacked an understand-ing of the complexity of the problem—the importance, complexity, and widevariance of metal microstructure; thesensitivity of test equipment required;and the need for realistic electro-migration testing. We could probablydevelop a predictive methodology forcomponent end-of-life reliability usingprecursors as impending failurewarnings, given a realistic appreciationof the complexity of such a task and acorrespondingly appropriate alloca-tion of funds.


3520.240

An Extensible Object-Oriented Framework for Riskand Reliability Analysis

G. D. Wyss, D. R. Funkhouser, R. L.Vandewart, R. L. Craft

To assess a system’s risks, ananalyst must understand the system’sdynamics and structure and have expertdomain knowledge (particularly inviable faults and attacks). The largevolume of information required canobscure the system-wide effects ofchanges in a given system element. Thisproject developed a demonstrationprototype for an extensible tool tosupport risk assessment of multi-disciplinary systems. The projectestablished the requisite theoreticalbasis for an object-oriented risk analysisapproach. In this approach, each systemelement is represented by a risk objectthat contains a knowledge base aboutthe element’s failure modes, supportrequirements, and spatial and temporalcharacteristics. In addition, each objectcontains pieces of generic risk modelsthat can be automatically assembled toform system risk models. Through ablend of object-oriented system model-ing, simulation, and expert decisionaids, the tool provides a framework forthe capture and presentation of currentand future expert risk knowledge. Asevery risk analysis model is currentlyhand-tooled, encapsulating domain-specific knowledge into risk objectsenables risk analysts to generate studiesmore quickly and with greater confi-dence that they have not omittedimportant risk sources, thus spendingless to obtain a better product.

We demonstrated that conceptsderived from object-oriented analysisform an excellent common languagefor the information required by systemdesigners, simulators, and suretyanalysts, and that this language canform the basis for a knowledgerepository that is common to all ofthese disciplines. We also demon-strated that the models required to

perform surety analyses (especiallyrisk and reliability analysis models)can be derived from the object-oriented analysis methodologyprovided that the concepts embodiedin the object models support bothinductive and deductive qualitativereasoning. We also demonstrated thatall major elements of this modelingmethodology will be representable in astandardized language once theUniversal Modeling Language (UML) isextended to incorporate data-flowdiagrams. Commercial off-the-shelfsoftware to implement UML is alreadyavailable. We also developed system-atic rules by which one can automatethe derivation of many surety analysismodels from a single common objectmodel. Derivable analysis typesinclude failure modes and effectsanalysis, HAZOP (hazards and oper-ability study), event trees and faulttrees, and discrete simulation analy-ses. We implemented the fault treemethodology in a simple demonstra-tion program that made use of JAVAprograms coupled to the ROSEcommercial computer-aided softwareengineering tool. The fact that we wereable to generate these rules andimplement them in software meansthat we were able to prove the majorportion of our hypothesis: namely, thatit is possible to construct a singleobject–based model to represent thebehavior of a system, and to automati-cally extract from that object model awide variety of types of risk andreliability analysis models. Anotherpoint that we verified under thisproject was the ability to constructgeneric object models for individualcomponents that can be assembledand customized rapidly to build thecommon object model. This stands instark contrast to traditional risk andreliability model development tech-niques, which require a human analystto construct each individual model byhand. Thus, the methodology devel-oped under this project can dramati-cally reduce the amount of timerequired to develop risk and reliabilitymodels for complex systems.

Publications

Refereed

Craft, R. L., G. D. Wyss, R. L.Vandewart, and D. R. Funkhouser. 1998.“An Open Framework for Risk Manage-ment.” Proc. 21st Nat. Inform. Sys. Scty.Conf. 1 (Arlington, VA, 5–8 October):291–302.

Wyss, G. D., R. L. Craft, R. L.Vandewart, and D. R. Funkhouser. 1998.“Recasting Risk Analysis Methods inTerms of Object-Oriented ModelingTechniques.” Sys. Safety: The TotalSolution, Proc. 16th Internat. Sys. SafetyConf. 1 (Seattle, WA, 14–19 September):198–207.

3520.270

Simulation/OptimizationTools for System VariabilityAnalysis

J. E. Campbell, B. M. Thompson, K. D.Marx

Sandia has used electrical systemsimulation successfully over the pastdecade. Two common applications are(1) supporting the electrical systemdesign process and (2) analyzinganomalies detected in the fieldedproduct. Simulation also has a futurerole in helping to predict failures whendegradation precursors are identified. Inshort, electrical simulation is a tool thatcan be used during the entire productlifecycle to develop an understanding ofthe system over the range of expectedconditions.

Electrical simulation typicallytreats a single data point in the verylarge input space of component proper-ties. For electrical simulation to reach itsfull potential as a design tool, it must beable to address the unavoidablevariability and uncertainty in componentproperties. Component variability isstrongly related to reliability of the endproduct. This project addresses a set ofproblems that hinder effective use ofsimulation, especially in the context ofunderstanding variability.


The first goal of this effort was tocreate a novel linkage of disparatevariability analysis approaches togreatly reduce the overall analysis time.There is an associated need for method-ologies to effectively apply this toolset toa range of problem types. The secondgoal is to develop an approach toquantify the reliability impacts ofvariability, especially for time-dependentissues. Ultimately, we will explore thebenefits and limitations of the developedtools and methodologies, including aconsideration of the uncertainties andunderlying assumptions.

In pursuing this project, it becameapparent that there are two complemen-tary paths to be explored: variabilityanalysis and optimization. Each has itsrole in the product lifecycle, and eachposes a unique set of challenges.

I. Selection of Analysis Issues• Identify specific stockpile

problems of interest to analyze (agingand nonaging).

(1) We identified and analyzed asimple filter problem to test thevariability analysis toolset.

(2) After an initial parameterscreening study, we may use the toolsdeveloped in this project to analyzevariability for both aging and nonagingparameter sets.

(3) We are developing anattributes data (pass/fail) contour for afiring set high-voltage breakdownissue. We are examining three param-eters (breakdown resistance, induc-tance, and time) using the projecttools.

II. Tool Linkage• Develop software for linked

input vector generation and net listformulation.

This software is currently in twopieces. The first converts an inputvector file into a form that can beparsed and combined with a circuitfile; this is a combination of SUNS

(Sensitivity and Uncertainty AnalysisShell), which creates an input vectorfile of sample values, and someadditional code that converts an inputvector file into a form that can beparsed. The second actually parses theinput vector and builds the circuit netlists.

• Explore means for MPACTR(Massively Parallel ComputerResource) program management andinput/output (I/O) management.

(1) We selected a newer versionof SPICE (Simulation Program withIntegrated Circuit Emphasis) (3f5) thathas more capability and will also runon the MPACTR machine.

(2) In conjunction with anotherproject, we implemented the MPACTRDistributed Queuing System (DQS) toallow for program and I/O managementof multiple SPICE jobs.

• Formulate a set of softwareroutines to automate extraction ofresponse variable values from outputdata (include such variables as rise/falltimes, peak values, pulsewidths, etc.).

We implemented one customdata-extraction routine (selection of a3 dB cutoff frequency).

• Link software elements for theend-to-end tool package.

We made significant progress incoupling the tools for variabilityanalysis.

(1) The kernel of the variabilityanalysis toolset, SUNS, is now runningunder Windows, and we completed adraft user’s manual.

(2) The kernel of the optimiza-tion analysis toolset, GO (GeneticOptimization), is now running underWindows, and we completed a draftuser’s manual.

(3) We developed a script thattakes an input vector and converts itinto a set of net lists that are thenautomatically executed on theMPACTR machine.

(4) Another script extractsoutputs from the SPICE files andconsolidates them for analysis.

III. Tool Use Methodology• Identify issues and caveats for

top-down and bottom-up approaches.We have explored two method-

ologies for SUNS to date:(1) Determining the impact of

input parameter variability on systemoutput and system output variability(R/C [resistor/capacitor] circuit cutofffrequency example).

(2) Using a state-space examina-tion to generate an attributes (pass/fail) contour. This is a first step inmapping variability to reliability. Othermethodologies (particularly top-downapproaches) remain to be developed,including (a) parameter screening, (b)attributes contours in the presence ofvariability, and (c) optimization fordesign-for-reliability.

• Work selected problems withunlinked tools and validate.

The firing-set high-voltagebreakdown problem is in progress. Wewill complete the variability analysis ofthe W80 firing set.

IV. Reliability Methodology• Identify issues and caveats for

top-down and bottom-up approaches.We have explored two method-

ologies for SUNS to date:(1) Determining the impact of

input parameter variability on systemoutput and system output variability(R/C circuit cutoff frequency example).

(2) Using a state-space examina-tion to generate an attributes (pass/fail) contour. This is a first step inmapping variability to reliability.

• Work selected problems withunlinked tools and validate.

The firing-set high-voltagebreakdown problem is in progress.


3520.280

A Massively ParallelMicrosimulation Model ofInfrastructureInterdependency

D. C. Marozas, R. J. Pryor, D. L. Harris

The U.S. infrastructure is acomplex system of interdependentelements whose continued operation isvital to the security of the United States.These interdependencies create tremen-dous vulnerabilities that must be under-stood and managed to minimize theimpact of deliberate disruptions, humanerror, or natural disasters to the surety ofthe infrastructure system. We areutilizing Sandia’s unique microsimula-tion approach to develop a model ofcritical infrastructure interdependencies.This simulation technology capitalizeson recent technological advances inevolutionary learning algorithms andmassively parallel (MP) computing. Wemodel interactions individually amonginfrastructure elements by intelligentagents—one for each interaction. Thismodeling protocol can utilize thousandsof agents to model very complexsystems and offers several advantagesover traditional modeling techniques formodeling infrastructure interdependen-cies. For example, unlike analyticmodels, functional forms of the model’sendogenous relationships are notrequired. For problems where macro-scale information is sparse or nonexist-ent, as is the case for infrastructureinterdependencies, microsimulationmodels are differentiated in theircapacity to utilize existing rich sourcesof microlevel data to develop interactionforecasts.

Extending Sandia’s ASPENmicrosimulation model of the economyto include rules and interactive agentsfor additional infrastructures willimprove ASPEN’s capabilities to thestudy of extremely complex, intercon-nected networks. In addition, we areusing ENERGY 2020, an existing agent–

based, regionalized, interdependency-focused energy model as the prototypefor a microsimulation model of theenergy infrastructure. This combinationwill provide a powerful framework forquickly delivering a credible model ofthree infrastructures (i.e., telecommuni-cations, banking and finance, andpower) most critical to the nation’seconomy and security.

We modified Sandia’s ASPENprogram to incorporate the effects oftelecommunication disruptions. Wealso improved simulation methods toaccount for shocks resulting fromcommunication disruptions. To testcoding changes, we modified ASPEN’sprototype model and analyzed severalcalculations of disruptions of varyingdegrees. We created a single processorversion of the code to run on a fastworkstation to improve testing speedand to provide a version of the codethat could be delivered to customersfor direct use. We also developed auser interface for the Internet, whereoutside users can set up and runsimulation problems in ASPEN thatinclude telecommunication disrup-tions. Results from the telecommunica-tion prototype indicate that infrastruc-ture disruptions can be modeled withASPEN. We identified and are incorpo-rating software changes into thedevelopment model. We collected dataon wide-area telecommunicationoutages to provide information forcalibration and to identify agentbehavior during disruptions.

To rapidly build a model capableof addressing multi-infrastructures, weevaluated a well-established planningand policy analysis model, ENERGY2020, for its potential to be combinedwith ASPEN and to provide a prototypefor the electric and gas/oil infrastruc-ture. Like ASPEN, ENERGY 2020 is anagent–based simulation model, but isfocused on energy infrastructureinteractions and thus provides agentdefinitions for electric and gas utilities.Like ASPEN, it models fundamental

infrastructure system feedback loops,critical to understanding and predict-ing responses to unexpected perturba-tion or shocks. The ENERGY 2020 codeis written in a dynamic simulationlanguage called PROMULA that is nottransferable to Sandia’s multipleprocessor computer platforms. Todevelop a combined economic/energyinfrastructure model, we wrote atranslator that reads PROMULA andconverts the code to C++, which iscompatible with Sandia’s high-perfor-mance computing platforms. Wesuccessfully converted a simplifiedversion of ENERGY 2020 to C++ andinserted message-passing interface(MPI) calls in the code to allow it to beexecuted on the DEC 8400 multiproces-sors. We parallelized ENERGY 2020 inseveral ways: (1) ran a differentscenario on each processor, (2) ran adifferent state, economic category, andelectric company on a separateprocessor, and (3) ran parts of eachprocedure on each processor.

We modified the PC version ofENERGY 2020 to simulate dailydispatch of the power plants and trackunserved power load due to outages.We revised the seasonal dispatch tosimulate twelve time periods (Mondaythrough Friday for the summer andwinter, plus a dispatch for the rest ofthe summer and the rest of winter). Weran this model with a one-day outageto several generating units andtransmission lines both with andwithout any gaming. In this case,gaming means generators who adjusttheir prices to increase their revenues.We are using results to evaluate theENERGY 2020 model for estimating theimpact of power outages and todevelop a strategy for incorporatingpower disruptions in a combinedASPEN/ENERGY 2020 model in the nextfiscal year.

Developing the behavioralalgorithms for individual agents in amulti-agent model is one of thechallenges of producing useful models.


We investigated both genetic algo-rithms and genetic programmingapproaches for developing price-setting strategies for industrial agentsin ASPEN. We developed a JAVA toolkitof genetic algorithms for use onSandia’s MP DEC8400 computer.

Publications

Other

Pryor, R. J., D. Marozas, M. Allen, O.Paanen, K. Hiebert-Dodd, and R. K.Reinert. 1998. “Modeling Requirementsfor Simulating the Effects of ExtremeActs of Terrorism: A White Paper.”Sandia Technical Report SAND98-2289(October). Sandia National Laborato-ries, Albuquerque, NM.

3520.320

Reliability Predictions forAdvanced Electronics inSmoke Environments

T. J. Tanaka, S. P. Nowlen, V. F.Nicolette, C. R. Shaddix, J. E.Brockmann, D. J. Anderson, C. W.Bogdan, L. A. Gritzo

Smoke causes disruption andfailure of advanced electronics byincreasing conductivity. The conductivityis highest while the smoke is in the airand decreases as the smoke settles or isvented away. Video recordings showthat delicate soot chains form on high-potential surfaces and may create solidsoot bridges. Air movement breaks thesoot bridges and reduces conductivity ifthe smoke concentration drops. Thisproject will model smoke effects onelectronics as a function of the type ofsmoke by measuring real-time electricalparameters. This model can be used toinclude the effects of smoke in fire-riskassessments.

The real-time measurementsinclude smoke conductivity for differentdc voltages, and conductance andsusceptance for a range of ac frequen-cies. Sandia will use the conductivityinformation in conjunction with anelectrical circuit modeling program,Simulation Program with IntegratedCircuit Emphasis (SPICE), to determinethe smoke concentration that shouldcause failure. We will test the modelusing memory chips and other equip-ment contributed by outside sponsors.The failure of the electronics will thenbe linked with fire models that calculatesmoke production and transport.

Our goal was to measure theparameters that are important incausing failure in electronics. Using asmall-scale smoke-exposure chamberdeveloped for the U.S. Nuclear Regula-tory Commission, we developed,purchased, or borrowed hardware andsoftware to measure these parameters.The measurements include conductiv-ity between parallel plates, conductiv-ity on surfaces, dielectric constant,smoke mass density, smoke opticaldensity, soot deposition, and digital-signal error rate.

Three significant improvementsto the smoke research include two newcomputers, a modern program tocontrol the smoke exposure andmeasurements, and a new multimeter.Because of these improvements, themeasurement cycle time decreasedfrom 1 minute to 10 seconds. Weupgraded the smoke optical density toa laser beam and built a manifold toobtain multiple filter samples. Weupgraded the computer system,developed a new program to controlthe system, and began the tests, whichare proceeding rapidly. We burnedpolyvinylchloride cable insulation, JP-8aviation fuel, and douglas fir toproduce the smoke.

Our measurements show thatconductivity between the parallel

plates increases when soot, attractedto high-voltage surfaces, collects aslong chains and forms bridges betweenthe surfaces of opposite polarity. Thesoot collects on high-voltage surfacesjust as dust collects on electrostaticprecipitators. The soot chains arefragile and can be broken by airmovement, but can rebuild if thesmoke concentration is high. Thechains are best produced by soot fromflaming fires. Smoldering fires produceconductivity on surfaces, but do notbridge air gaps. High conductivity onparallel plates occurs for JP-8 andcable insulation.

The conductivity increases withthe amount of fuel burned and canremain significantly high if little airmovement is induced in the smokechamber, even if the smoke concentra-tion drops. Because of the solid natureof the soot bridges, the conductivity isnot directly proportional to the smokeconcentration as measured by opticaldensity. We assume that the conductiv-ity of the soot is dependent on thechemicals present and the humidity,and we plan to measure the conductiv-ity per mass or volume of soot col-lected on high-potential surfaces.

The multiple air filter samplesshow that the optical density isproportional to the mass density.These measurements are comparableto results of other researchers at theNational Institute of Standards (NIST).This research has increased interest insmoke effects during fires.

Publications

Refereed

Tanaka, T. J., and J. T. Chapin. 1998.“The Effect of Smoke from Plastics onDigital Communications.” Paperpresented to the Plastics in Telecom-munications Conference VIII, London,UK, 14–16 September.


3520.290

Physical Models forPredicting the Effect ofAtmospheric Corrosion onMicroelectronic Reliability

J. W. Braithwaite, D. G. Robinson, J. N.Sweet, D. W. Peterson, N. R. Sorensen

Atmospheric corrosion is theleading age-related degradation modeobserved in the weapon stockpile. Ofparticular interest is corrosion-inducedfailure of electronic components(including microelectronics) because ofthe direct consequence to function andtherefore reliability. Sandia is nowaddressing the probable insertion ofplastic-encapsulated microelectronic(PEM) devices in future weapon systemsand upgrades. These devices use plastic-molding materials that make many ofthe metallization features susceptible tocorrosion. In nuclear weapon compo-nents, the failure rate due to corrosionmay dramatically increase during long-term dormant (unpowered) periodswhen the die surface is not dried out dueto internal ohmic heating. This failuremode is currently being ignored byindustry. Analytical tools that caneffectively assess the reliability of PEMdevices must be based on a physicalunderstanding of the moisture-relatedphenomena relevant to metallizationfailure. The objectives of this project areto provide this needed physical basisalong with an associated mathematicalmodel of the degradation process ofprimary interest: bondpad corrosion. Weare following a phased inside-outapproach: (1) intrinsic bondpadcorrosion behavior as a function ofphysical configuration and environmen-tal parameters, (2) extrinsic effects ofencapsulant materials, and (3) integra-tion and refinement of a corrosion-process model. We are applyingcomputational reliability techniques topermit the uncertainties inherent in thedegradation, the transport processes,and the storage environments to beefficiently addressed. Two importantinitial outcomes will include a quantita-tive assessment of the validity of thePEM storage concern and a demonstra-

tion of the attractiveness of usingcomputational reliability to modelmaterials-degradation processes.

We made important progress infour key areas related to corrosion inPEM devices: (1) development ofcharacterization/monitoring tech-niques, (2) measurement of intrinsickinetic parameters, (3) identification ofthe factors that affect corrosion, and(4) reliability simulation using apreliminary mathematical model.

• Corrosion monitoring. Wecharacterized corrosion and moni-tored it quantitatively as a function ofenvironmental and device-configura-tion variables using two test struc-tures: a Sandia-developed test chip andtransparent quartz slides onto whichgold/aluminum (Au/Al) wirebondswere deposited. We used the chipdevice primarily to monitor bondpadresistance (a measure of the extent ofcorrosion), and the quartz–basedstructure was attractive for character-izing corrosion initiation and propaga-tion behavior. A good correlationexists between time–based resistancemeasurements, visual/optical observa-tions, and expected environmentaleffects (e.g., increased rate at highertemperature and humidity). Theseresults validated the use of change inresistance as a measure of the extentof corrosion. Relative to contamina-tion, we used two techniques tosimulate potential exposures: contami-nation during manufacture andcontamination due to exposure toindustrial pollutants.

• Kinetic property measurement.Typical kinetic results obtained fromthe test chip device showed that underthe constant environmental condi-tions, a linear kinetic relationshipexisted between bondpad resistanceand time. Considerable scatter existedin these rate data between individualbondpads on the same test device, asituation that was probably due tophysical configuration effects (bondlocation, water condensation, pres-ence of intermetallic compounds,galvanic coupling), or possibly thestochastic nature of the Al corrosionprocess.

• Mechanism identification. Weused thin-film Al test structures toidentify how Al bondpads actuallycorrode in microelectronics. Usingbacklit optical microscopy, we showedthe density and size of the corrodedareas to increase with increasing time.Digital image analysis enabled thecorrosion initiation and propagationrates to be quantified. Importantly, weobserved corrosion only in the area ofthe Au/Al couple where the Au wasthin enough to be porous. Thisobservation, combined with the lack ofany observable corrosion onnonbonded Al pads or Al/Al wirebonds(in either NaCl or chlorine gas), clearlydemonstrated the critical function ofthe Au/Al galvanic couple. Thecorrosion that did exist on the test-chip bondpads appeared to be generalrather than localized and was probablyassociated with the intermetalliccompounds that formed during ultra-sonic bonding. Cross-sectioned bond-pads identified the existence of aphysical crevice under the peripheryof bond that could function as a sitefor capillary condensation.

• Mathematical modeling.Although a number of physicalprocesses have yet to be completelycharacterized, we developed andexercised a preliminary PEM corrosionmodel to improve the efficiency of theexperimental activities and to providea focal point for achieving the ultimateproject objective. We based this modelprimarily on the ongoing experimentalstudies; it consisted of a governingequation that described the rate ofrelative increase in bondpad resis-tance. This simple equation containedthree distributed parameters: a surfacereaction-rate constant that includedthe previously discussed stochasticsof corrosion propagation in Al, andtwo environmental parameters(temperature and relative humidity)that vary with time and incorporate aspecific time–based uncertainty. As avehicle for the model development andcapability demonstration, we thensuccessfully performed a numericalreliability simulation in which we agedLM185 voltage reference devices in


desert, Gulf Coast, and arctic environ-ments. Chlorine gas was the onlycontaminant considered. We calcu-lated values for the kinetic parameters(and their variability) using averagedkinetic-rate constants. Because of thepresence of the nondeterministicparameters and the knowledge thatmuch more complicated chemical andphysical processes must be incorpo-rated in the future, we used thecomputational reliability techniques(i.e., CRAX) being developed tonumerically solve this equation.

Publications

Other

Braithwaite, J. W., and N. R. Sorensen.1998. “Physical Models for Predictingthe Effect of Corrosion on Microelec-tronics Reliability.” Paper presented tothe Gordon Research Conference onAqueous Corrosion, New London, NH,8 July.

3520.310

Backside Localization ofOpen and Shorted IC(Integrated Circuit)Interconnections

E. I. Cole, Jr., D. A. Benson, P.Tangyunyong, D. L. Barton

Integrated circuits (ICs) are criticalcomponents of virtually every Sandiasystem. Open and shorted internal ICinterconnections are major reliabilityconcerns and have been significant instockpile systems. These failures occuras a result of processing defects and/orstress during operation and use. Bothfailure mechanisms have been signifi-cant in stockpile components. Localiza-tion of these defects has been extremelydifficult due to decreasing feature sizesand increasing levels of interconnec-tions. Concurrently, the implementationof flip-chip packaging (as in Sandia’sWarhead Protection Program [WPP] andMicroNavigator Program) has madebackside analysis the only feasibleexamination method in many cases.

Most active circuit elements in these ICsare accessible only from the backsideand, to date, there are no effectivebackside techniques to directly localizeopen and shorted interconnections.

We will continue our developmentof two new imaging techniques for ICbackside open and short localization:Seebeck Effect Imaging (SEI) forlocalizing open interconnections, andShort Localization (SL) for localizingshort-circuited sites. The imaging modesuse constant current biasing to makedefect activation by an outside stimulusmore readily detected. Our detectionmethod uses thermal gradients producedby a scanned infrared (IR) laser. Onopen interconnections, thermal gradi-ents induce voltage gradients (Seebeckeffect). Thermal gradients change theresistivity of electrical shorts. Botheffects are used to localize defects.

SEI and SL have the potential torevolutionize backside IC analysis in thesame way Sandia’s charge-inducedvoltage alternation (CIVA) technique hasfor frontside open interconnectionlocalization. Backside SEI and SL, forwhich there are presently no alterna-tives, could have greater benefits byproviding critically needed missing linksin analysis capabilities. Sandia’sdevelopment of SEI and SL will alsofurther the Nuclear Weapons StrategicManagement goals of reducing the timeand cost of analyses.

First-year work demonstratedthe feasibility of SEI and SL. Weacquired SEI and SL images on com-plex devices from the front andbackside of the IC. We localized openinterconnections produced by focusedion beam (FIB) modification anddesign errors using SEI. The imagedata clearly define the defect site. TheSEI images produced are the onlyknown method to directly detect andlocalize open interconnections fromthe backside of an IC. Examination ofdevices from the backside requireddevelopment of sample preparationtechniques that have maintainedelectrically active, packaged ICs withpolished die backsides for observa-tion.

We used SL to localize intercon-nection short sites resulting from FIBmodifications and stainless-steelparticle contaminants. Through metalprobing, we demonstrated detecting adefect covered by an interconnectionlayer with both SEI and SL, showing awider range of applicability thanoriginally expected.

We filed a patent for SEI and SL.Although still under development, SLhas already been used successfully in aSandia and an external customerfailure analysis. An existing Coopera-tive Research and DevelopmentAgreement (CRADA) partner hasexpressed interest in seeing if SEI andSL would be applicable to theirproduct.

Although we have demonstratedfeasibility, the SEI and SL signalstrength is presently weak comparedto other analysis techniques. The smallsignals can make image acquisitionvery difficult. Exploring methods ofimproving the sensitivity is the goal ofthe FY99 project.

Publications

Refereed

Cole, Jr., E. I., P. Tangyunyong, and D.L. Barton. 1998. “Backside Localizationof Open and Shorted IC Interconnec-tions.” Proc. IEEE Internat. ReliabilityPhys. Symp. 1 (Reno, NV, 31 March–2April): 129–136.

Cole, Jr., E. I., P. Tangyunyong, and D.L. Barton. 1998. “Local ThermalProbing to Detect Open and Shorted ICInterconnections.” Microelectron.Reliability (Invited). Oxford, UK:Pergamon (Elsevier Science).

Other

Cole, Jr., E. I. 1998. “Rapid Localizationof Interconnect Defects ThroughRecent Advances in Failure Analysis.”Paper presented to the 1998 AdvancedMetallization Conference, Seminar onFuture Technology (Invited), ColoradoSprings, CO, 5 October.


3520.330

Security of Bulk PowerSystems

D. G. Robinson, P. C. Butler

The electrical grids of NorthAmerica are an extremely large andcomplex set of interconnected networksvital to the economic lifeblood andsafety of over 380 million people. Thesenetworks are dynamic and constantlychanging systems whose surety (safety,security, and reliability) is vulnerable tosignificant disruptions due to evolvingenergy policies as well as from naturaland man-made sources. The President’sCommission on Critical InfrastructureProtection identified electric power as acritical infrastructure sector, of whichthese networks are essential compo-nents. Furthermore, electric-powerutilities are transitioning from a regu-lated, rate–based mode of operation inwhich utilities provide service to areasand customers on an exclusive franchisebasis to a mode of competitive energymarkets. It is inevitable that the transi-tion to competitive energy markets willimpact electric service reliability.Therefore, there is a need for modelsand methods to assess the likely

reliability impacts of utility deregulationand to provide guidance to energyproviders, regulatory agencies and othergovernment agencies, and the publicduring this process. In addition, thereexists an increasing problem of potentialphysical and cyber sabotage of keypower-grid elements. There is already acomplex interaction between infrastruc-ture elements (communications, power,transportation, etc.), and under restruc-turing, these interactions will increase inscope to a national level. Existingreliability assessment models are notcapable of accurately reflecting andassessing critical reliability issues, soimproved, more comprehensive modelsare needed.

We focused on three majorresearch areas:

(1) To deal with power flowanalyses at a national level, we starteddeveloping a new approach to networkmodeling. Current transportation anddc load flow models can be used tocharacterize large areas but lack theaccuracy to address voltage stabilityissues. However, the necessary ac flowmodels are too computationallycumbersome for even moderate-sizepower grids. Preliminary researchconducted in this area involved the

development of a hierarchical model-ing scheme with increasing modelfidelity driven by increasing networksensitivity.

(2) We looked at the probabilisticcharacterization of network stability.To address stability issues, we devel-oped a new probabilistic load flowmethodology that is supported by thereliability analysis software tools(Cassandra). We applied a prefatoryintegration of the Cassandra softwareand the ac load flow model to theModified IEEE (Institute of Electricaland Electronics Engineers) ReliabilityTest System and had encouragingresults.

(3) In addition to addressing theadequacy and stability issues associ-ated with power-grid reliability, weundertook preliminary investigationsto characterize and model advancedtechnologies to determine theirsuitability for addressing surety issues.Renewable generation, storage, andhigh-speed power electronics andswitches are candidates for solvingmany of the problems identified aboveand are areas of expertise in theorganizations involved with thisresearch.








NATIONAL GRAND

CHALLENGES

Projects that promise dramatic impact by atleast a factor of two on national concerns—such ashealth care, transportation, and counterterrorism—comprise the National Grand Challenges. High-risk,potentially outrageously successful ideas in all areasare encouraged. This activity includes a number of possible areasof interest: research projects that could facilitatecutting nonfossil energy prices in half, majorreductions in health-care costs with concurrentimprovements in quality and availability, reducingthe cost of pulsed power substantially below onedollar per megawatt of radiated power, and developingpetaflop computing capabilities and applications.All proposals must support achieving Sandia’sbusiness goals. The current National Grand Challenge involvesdevelopment of an autonomous microchemistrylaboratory. Imagine bands of tiny vehicles thatcooperatively canvass the countryside, sniffing outsuspicious or threatening chemicals, or evenlandmines buried beneath the soil. About 40 scientistsand engineers at Sandia National Laboratories havebeen researching how to create such technology overthe past year in the largest project of its type everfunded by the Department of Energy. At the end ofthree years, they hope to demonstrate a device aboutthe size of a palm-top computer that can sniffexplosives and chemical warfare agents. In 5 to 10years, devices should be able to simultaneouslyidentify hundreds of liquids and gases. Arrays of these chemistry-labs-on-a-chip couldbe sent onto battlefields or mounted near factoriesto provide chemical reconnaissance. The sametechnology might also provide quick diagnosticscreening at a patient’s bedside. Inexpensive massfabrication, based on existing microchipmanufacturing techniques, could spur widespreaduse of microChemLabs. Potential national securityapplications range from detecting weapons of massdestruction to monitoring the state of the nuclearstockpile. Everyday items employing similartechnology might also become available one day inneighborhood stores to test water and food, orperhaps in other areas to monitor the course of anillness or to determine the safety of the immediateenvironment.





3522.010

Science on the Microdomain

T. A. Michalske, G. C. Osbourn, C. C.Wong, W. Wolfer, J. L. Dohner, M. H.Crawford, M. E. Warren

The ability to shrink sophisticatedchemistry laboratories to pocket-calculator size and smaller will revolu-tionize chemical detection in a mannersimilar to the way that integrated circuits(ICs) revolutionized informationtechnology. Sandia can lead this fieldbecause we have the science andtechnology base to address all aspects ofcomplex microsystems. We demon-strated our expertise in silicon (Si)micromachining, microsensors, andphotonics, and are receiving significantexternal recognition for our accomplish-ments. However, as our recentlycompleted Integrated MicrosystemsRoadmap points out, several criticalscientific frontiers must be tamed beforewe can capitalize on the substantialmilitary and intelligence–based businessopportunities offered by this rapidlydeveloping technology. The goal of thisproject is to provide the technical focusneeded to ensure Sandia’s leadership inthe invention and application of theMicroChemLab (µChemLab). We willdemonstrate the world’s first mobile,autonomous µChemLab for explosiveschemical detection.

We proposed a focused laboratorythrust on the science of the micro-domain. This regime of very small sizes(roughly 0.1 mm and below) is newterritory for machines where normalintuition and standard engineeringmodels cannot be scaled to predictperformance, reliability, aging, ormanufacturing. This project will developthe scientific basis to understand andpredict microscale processes involvingmicromechanics, transport, microopticsand sensing, and multivariate analysisthat lead not only to the invention of amobile, autonomous µChemLab, butalso provide the engineering foundationto address the key technical objectivesof reliability, performance, andmanufacturability in future microdeviceapplications.

The Science of the Microdomainproject within the µChemLab Grand

Challenge is organized into fivetechnical focus areas: (1) integratedoptics, (2) on-board data analysis, (3)microscale transport, (4) micro-mechanical actuators, and (5) in situdiagnostics. In the integrated opticsarea we successfully demonstrated thespectrometer on a chip; produced ablue-and-green-emitting, doubled,vertical-cavity surface-emitting laser(VCSEL); demonstrated ultraviolet(UV) emission from a GaN diode; andconducted the first flow experimentsin microcavity sensors. In the on-boarddata analysis area we developed apseudo-floating-point library for theon-chip processor and analyzed firstcontinuous-wave (CW) simulant datafrom integrated preconcentrator andsurface acoustic-wave (SAW) array. Inthe microscale transport area wedeveloped a liquid-flow model todescribe electrokinetic transport inpacked columns and used gas-flowmodeling to optimize the micro-machined gas chromatography (GC).In the micromechanical actuators wemodeled the magnitude of acousticstreaming as a gas-pumping approach.In the in situ diagnostics we designedand manufactured a membranedeflection–based pressure sensorusing piezoelectric transducer films.We also fabricated and packaged it andbegan performance testing. Wecompleted the design of athermocouple–based bridge-type flowdetector, and fabricated and aretesting the prototype device.

3522.030

Cooperative, DistributedSensing and Action UsingMicrominiature, IntelligentAgents

B. L. Spletzer, P. C. Bennett, T. M. Weber,C. L. Lewis, P. G. Xavier, P. R. Klarer

This project will complete thedevelopment of a strong technical basefor modeling, simulating, designing,evaluating, developing, and deployingmicrominiature intelligent machines.The main thrust of the project is to buildhardware-verified simulation tools and

to develop control systems for cooperat-ing intelligent agents. Sandia willdemonstrate the achievement of thismain thrust by deploying multipleautonomous microChemLabs(µChemLabs) in a cooperative sensingenvironment. We will produce theworld’s first mobile autonomouscooperative µChemLab as part of thehardware verification to performdetection and localization of a chemicalsource. This project will position Sandiaas a leader in the community ofresearchers in computer science andmathematics regarding cooperativebehavior and as a supplier of micro-miniature intelligent systems andtechnology.

(1) We completed the simulationto the extent of providing a powerfultool for investigating and observingcooperative behavior of both large andsmall groups. We simulated as many as100 vehicles in real time. In addition,the simulation provides the capabilityto run multiple control and behavioralgorithms simultaneously to simplifydirect comparison between competingschemes.

(2) We procured and are evaluat-ing the first advanced power supply, afuel cell, for integration into theRobotic All-Terrain Lunar ExplorationRover (RATLER) test-bed vehicles.

(3) We conducted preliminarydemonstrations with the swarm ofRATLER vehicles, demonstrating theusefulness of cooperative behavior.

(4) The integration of theRATLER test-bed vehicles with thesurrogate µChemLab sensor is underway. Until the µChemLab is available,we will use corona discharge sensorsto detect the presence of SF6 in theatmosphere. As long as the plumespecies can be selected, simple gasdetectors are adequate for demon-strating the usefulness of cooperativebehavior.

(5) We developed several verypromising control and behaviorstrategies that demonstrated that inreal-world problems, cooperativebehavior can effectively localize achemical source where similar agentslacking cooperation are unable tocomplete the task.


3522.020

Autonomous MicroChemLaboratory (µChemLab)

G. C. Frye-Mason, S. A. Wright, S. A.Carichner, W. B. Chambers, S. H.Kravitz, D. J. Rakestraw, G. N. Ryba

This project will lead to a newgeneration of field-ready, compact,chemical analysis devices that will haveunprecedented capabilities for measur-ing and deciphering detailed chemicalsignatures. At the end of three years, wewill demonstrate an autonomousmicroscale chemical laboratory(µChemLab) that will establish Sandiaas a leader in this field. This project willposition Sandia to support increasingdemands for detailed chemical informa-tion by current national securitycustomers and is essential for develop-ing new customers in nonproliferation,counterterrorism, and critical infrastruc-tures. The µChemLab, formed byminiaturizing and integrating sensingcapabilities, sampling and separationsystems, power sources, and systemsarchitecture, would meet the needs ofapplications in Defense Programs (DP)(nuclear material monitoring, materialaging), NN (National Security andNonproliferation Office) (nonprolifera-tion, cooperative monitoring), intelli-gence agencies (covert sensing), DoD(landmine detection, battlefield chemi-cal warfare/biological warfare [CW/BW] monitors), and energy and environ-ment (E&E) (in situ probes).

• System design and integration.We developed the preliminary systemdesign for the µChemLab together withrequirements for major systems andsubsystem components and presentedit to the External Advisory Committeeand µChemLab team. We partitionedthe design to the product teams,defined interfaces, and agreed on aschedule. We completed mechanicalintegration design concepts and areprototyping detailed designs. Wecompleted electronic integrationdesign architecture, selected compo-nents, and conducted feasibilitystudies on power supplies and micro-processors.

• Liquid-phase analysis. Weestablished three rapid separationmethods for parallel analysis ofexplosives. We demonstrated detec-tion limits of < 100 ppb for explosivesin a high-speed micellar electrokinetic(EK) separation using indirect laser-induced fluorescence (LIF) detection.We demonstrated microelectro-chemical detection of explosives inflow injection at < 10 ppb. We demon-strated insulation of silicon (Si) usinglayered Si2N3 and SiO2 up to 3,000 volts.We developed a patterned polyimidesealing technique for microchannelsand fabricated patterned chromato-graphic supports in Si and crystallinequartz. We packed microfabricatedchannels with SiO2 particles forchromatography. We characterized EKpumping in detail with various materi-als and solvents.

• Gas-phase analysis. We fabri-cated and tested prototype devices forthe three gas-phase components andestablished baseline designs for thesecomponents. We demonstrated thefirst functional integrated galliumarsenide (GaAs) surface acoustic-wave(SAW) oscillators this year. We alsoproduced discrete GaAs amplifierintegrated circuits (ICs) suitable forhybrid integration with GaAs SAWdelay lines. The packaging andinterconnection of the gas-phasecomponents made significantprogress. We successfully demon-strated techniques for attaching lidsand microcapillary tubing to all threecomponents. The most successfultechniques include anodic bonding ofPyrex to Si and the use of ultraviolet(UV)-curing epoxies. Regardingchemically selective materials, wedeveloped techniques for spray-casting through masks to depositpolymers and sol-gels into selectedregions of miniature preconcentratorsand acoustic-wave detectors. Weestablished an automated vapor-generation system in conjunction withother programs that can provide ppblevels of CW agent simulants with upto 100 ppm levels of interferantvapors.

• Sampling, fate, and transport.We evaluated the TOUGH2 series of

codes, and the modifications consid-ered are currently in progress. Thephysicochemical constants beingevaluated include water solubility, soil-water partition coefficients, and soil-vapor partition coefficients. Wecompleted the water solubility workusing the generator column methodunder dynamic conditions on TNT,DNT, and RDX. Development of solid-phase microextraction techniques forin situ soil and water analysis resultedin a technical advance and patentapplication for landmines and buriedunexploded ordnance (UXO) detec-tion. Similar success was demon-strated for water analysis with applica-tions to sea mines and submergedUXO.

• Micro-fuel-cell-on-a-chip powersource. We demonstrated platinum(Pt)-coated porous Si to electrolyzewater. We also demonstrated 1 cm-diameter porous Si membranes underroutine fabrication in 3-inch and 4-inchwafers. We developed process stepsand Si membrane backing. We maskedelectrode structures and vapor-deposited them on catalyzed porousSi. We constructed a test stand fortesting anode and cathode structures.We developed a plasma-derived Sicarbide mask (replaces SiN). We alsodeveloped high-aspect-ratio Si shadowmasks made with Bosch process toenable photoresist patterning onporous Si.

Publications

Refereed

Arnold, D. W. 1998. “Capillary Electro-chromatography.” Paper presented tothe High-Performance CapillaryElectrophoresis Conference, Orlando,FL, January.

Arnold, D. W. 1998. “Laser Applicationsto Chemical and EnvironmentalAnalysis.” Paper presented to the OSATopical Meeting, Orlando, FL, 9–11March.

Bailey, C. G. 1997. “Capillary Electro-chromatography.” Paper presented tothe Gordon Conference on IllicitSubstance Detection, Oxford, England,August.


Bailey, C. G. 1998. “Capillary Electro-chromatography.” Paper presented tothe High-Performance CapillaryElectrophoresis Conference, Orlando,FL, January.

Bailey, C. G., and C. Yan. 1998. “Separa-tion of Explosives Using CapillaryElectrochromatography.” Anal. Chem.

Casalnuovo, S. A., E. J. Heller, V. M.Hietala, A. G. Baca, R. J. Kottenstette,S. L. Hietala, and G. C. Frye-Mason.1998. “Acoustic-Wave Chemical Micro-sensors in GaAs.” Proc. 1998 SPIEMicromachining and MicrofabricationSymp. (Santa Clara, CA, 20–22 Septem-ber).

Casalnuovo, S. A., G. C. Frye-Mason,and S. L. Hietala. 1998. “Surface andBulk Micromachining of Thin GaAsMembranes for Acoustic-Wave Chemi-cal Microsensor Applications.” Proc.1998 Solid-State Sensor and ActuatorWorkshop (Hilton Head, SC, 3–8 May).

Chambers, W. B., J. M. Phelan, R. J.Rodacy, and S. W. Webb. 1998. “Chemi-cal Detection of Buried, UnexplodedOrdnance.” Paper presented to theUXO Forum ’98, Anaheim, CA, 4–7 May.

Chambers, W. B., R. J. Rodacy, E. E.Jones, B. J. Gomez, and R. L. Woodfin.1998. “Chemical-Sensing System forClassification of Mine-Like Objects byExplosives Detection.” Paper pre-sented to the International Symposiumon Aerospace/Defense Sensing,Simulation, and Controls, Orlando, FL,13–17 April.

Chambers, W. B., S. F. A. Bender, and P.J. Rodacy. 1997. “Analysis of Semi-volatile Nitroaromatic Compounds byHeadspace SPME.” Paper presented tothe 37th ORNL-DOE Conference onAnalytical Chemistry, Gatlinburg, TN,7–9 October.

Dadoo, R., C. Yan, R. N. Zare, D. S.Anex, D. J. Rakestraw, and G. A. Hux.1997. “Advances Toward the RoutineUse of Capillary Electrochromato-graphy.” LC GC-Magazine of SeparationSci. 15: 630.

Frye-Mason, G. C., R. J. Kottenstette, E.J. Heller, C. M. Matzke, S. A.Casalnuovo, P. R. Lewis, R. P.

Manginell, W. K. Schubert, and V. M.Hietala. 1998. “Integrated ChemicalAnalysis Systems for Gas-Phase CWAgent Detection.” Proc. Micro TotalAnalytic. Sys. (µTAS) Conf. (Banff,Alberta, Canada, 13–16 October).

Frye-Mason, G. C., S. A. Casalnuovo, E.J. Heller, R. J. Kottenstette, W. K.Schubert, C. M. Matzke, S. H. Kravitz,and M. C. Oborny. 1998. “Fabricationand Packaging of Integrated ChemicalAnalysis Systems.” Proc. IMAPS SensorPackaging Workshop (Ojai, CA, 26–28January).

Garguilo, M. G., P. H. Paul, and D. J.Rakestraw. 1998. “Imaging of Pressureand Electrokinetically-Driven FlowsThrough Open Capillaries.” Anal.Chem.

Heller, E. J., S. A. Casalnuovo, G. C.Frye-Mason, R. J. Kottenstette, A. G.Baca, and V. M. Hietala. 1998. “Optimi-zation of GaAs Surface Acoustic-WaveDelay Lines for Chemical MicrosensorApplications.” Proc. IEEE Freq. ControlSymp. (Orlando, FL, 27–29 May): 43.

Kottenstette, R., G. Frye-Mason, C.Colburn, E. Heller, J. Roark, M.Wilhelm, D. Newby, and M. la Grone.1998. “A Hand-Held SAW Array forVolatile Organic Compounds.” Paperpresented to the 193rd ElectrochemicalSociety Meeting, San Diego, CA, 6 May.

Lewis, P. R., G. C. Frye-Mason, R. J.Kottenstette, and J. Vitko, Jr. 1998.“µChemLab: An Update on the Inte-grated Chemical Analysis System forCW Agent Detection.” Paper presentedto the MASINT Chemical DefenseScience & Technology Symposium,Aberdeen, MD, 11 June.

Manginell, R. P., G. C. Frye-Mason, R. J.Shul, and C. G. Willison. 1998. “Micro-fabrication of Membrane–BasedDevices by HARSE and CombinedHARSE/Wet Etching.” Paper presentedto the SPIE Micromachining Micro-fabrication Conference, Santa Clara,CA, 20–22 September.

Manginell, R. P., G. C. Frye-Mason, W. K.Schubert, R. J. Shul, and C. G. Willison.1998. “Microfabrication of Membrane–Based Devices by Deep Reactive IonEtching (DRIE) of Silicon.” Paper

presented to the ElectrochemicalSociety Conference, Boston, MA, 1–6November.

Matzke, C. M., S. A. Casalnuovo, G. C.Frye, R. P. Manginell, D. Y. Sasaki, andC. C. Wong. 1998. “Integrated SiliconGas Chromatographic MicrochannelFabrication and Performance.” Paperpresented to the SPIE MicromachiningMicrofabrication Conference, SantaClara, CA, 20–22 September.

Paul, P. H., D. W. Arnold, J. J. Scherer,and D. J. Rakestraw. 1998. “High-Pressure Electrokinetic LiquidMicropumps.” Science.

Phelan, J. M., and S. W. Webb. 1998.“Chemical Detection of BuriedLandmines.” Paper presented to the 3rd

International Symposium on Technol-ogy and the Mine Problem, Monterey,CA, 6–9 April.

Phelan, J. M., and S. W. Webb. 1998.“Simulation of the Environmental Fateand Transport of Chemical Signaturesfrom Buried Landmines.” Paperpresented to the International Sympo-sium on Aerospace/Defense Sensing,Simulation, and Controls, Orlando, FL,13–17 April.

Rakestraw, D. J. 1998. “CapillaryElectrochromatography.” Paperpresented to the American ChemicalSociety National Meeting, New Orleans,LA, 2–5 March.

Rakestraw, D. J. 1998. “CapillaryElectrochromatography.” Paperpresented to the MASINT Chemical andBiological Defense Symposium,Aberdeen, MD, 11 June.

Rakestraw, D. J. 1998. “CapillaryElectrochromatography.” Paperpresented to the MASINT ChemicalDefense Science and TechnologySymposium, Wright Patrick AFB, FL,12–15 January.

Webb, S. W., S. A. Finsterle, K. Pruess,and J. Phelan. 1998. “Prediction of theTNT Signature from Buried Land-mines.” Paper presented to the TOUGHWorkshop ’98, Berkeley, CA, 4–6 May.










INITIATIVES

Initiatives supports studies in areas of urgentconcern to the DOE and Sandia. Energy productionis a vital national concern. Sandia developed atechnology at least two orders of magnitude betterthan current technology to monitor drill parameters.Surface area modulation telemetry was designed foroil production in a cased well. LDRD is provingSandia’s monitoring technology in more complexenvironments such as petroleum, geothermal, andenvironmental industries. In defense, developers need a powerful fabrica-tion tool to allow low-volume production of thecomplex shapes and materials found in highlyspecialized weapons components. Sandia developeda technology called Laser-Engineered Net Shaping(LENS™), using computer-controlled lasers that canweld air-blown streams of metallic powders intocustom parts and manufacturing molds. LENS™ canfabricate 3-D metallic components directly from CADsolid models, showing potential to revolutionize theproduction of metal parts such as complexprototypes, tooling, and small-lot production parts. Resulting materials have outstanding mechanicalproperties—very high strength and high ductility—and can mix powder streams of different materials.Engineers will eventually make intricate materialcombinations in complex geometries out of hard-to-machine materials. An early industrial application ofLENS™ to produce injection-molding dies saved morethan 50 percent in both time and cost overconventional methods. Other benefits include fabricating hardware withcomplex features and producing functionally gradientstructures made of multiple materials. As a materialadditive process, increased material utilization willcreate additional cost savings over a bulk removalprocess. LENS™ technology can also modify or repairexisting hardware. Microscopy studies show theLENS™ parts to be fully dense with no compositionaldegradation. Tests of several structural metal alloysreveal outstanding as-fabricated mechanicalproperties. University and industry collaboration providesenhancement of laboratory capabilities through aninflow of knowledge and skills from selectedresearchers who are leaders in their fields. Sandiarecognizes that much of the scientific expertise forthese emerging technical fields lies with universitiesand industry. These activities support the world-class, external sources of cutting-edge knowledgedevelopment that Sandia requires to develop criticallyneeded technical capabilities for the future.





3530.030

Computational Methods forPredicting the Response ofCritical As-BuiltInfrastructure to DynamicLoads (Architectural Surety)

R. V. Matalucci, S. W. Attaway

Sandia enhanced the PRONTO3Dstructural dynamics code to enable it tomodel the response of concrete, steelbeams and rebars, reinforced concrete,and reinforced and unreinforcedmasonry structural components. Weadded two major enhancements: (1) aconcrete material model, and (2) abeam/truss element to model the rebarsused in reinforced concrete and ma-sonry. We developed the beam elementformulation and used the existingconcrete and rebar material models andproperties to implement the enhance-ments in PRONTO3D. To verify theimplementation of the rebar andconcrete models, we defined severalbenchmark problems and ran themthrough PRONTO3D. To demonstrate thenew capabilities (i.e., rebar andconcrete models), we also ran applica-tion problems with PRONTO3D.

Adding the capability of model-ing reinforced concrete to PRONTO3Dhelped us develop an advancedcapability that would also provideairblast and structural calculationswithin a single coupled calculation.Other typical design issues andtradeoffs to be answered using thiscoupled analysis are whether increas-ing cladding or window strength islikely to put more load on columns andperhaps reduce the lethality for someexplosive attacks. Determining thecost of upgrades versus their effective-ness, comparison of design optionsvis-à-vis terrorist bombs, and estab-lishing effective standoffs for perim-eter barriers are also capabilitiesresulting from this effort. Couplingallows the airblast and responsepredictions to be performed together

so they may interact. The coupledcapability uses two existing Sandiacodes: CTH for predicting the blastenvironment and PRONTO3D for thestructural response. These codes arelinked into a single integrated analysiswith the ZAPOTEC code.

The combined airblast andstructural response calculation isespecially relevant to the analysis ofconventional buildings subjected toterrorist bombs because airblastpressures in those problems are oftenaffected by the structural failures theycause. The capability is particularlyuseful in predicting damage to thebuilding interior, determining claddingeffects on column failure, and applyingthe load in the correct spatial distribu-tion. Having a coupled code allows astraightforward, convenient means tosimulate the actual loadings becausethe pressure history and arrival timeof the loading are unique at everypoint in the building.

To verify the implementation ofthe material model, we ran severalbenchmark problems for the rebar(steel) and concrete materials. Theseresults indicated that both materialmodels satisfactorily match themeasured data. To illustrate thestructural response that PRONTO3Dcan determine, we developed severalmodels of reinforced concrete struc-tures and components from which wecarried out analyses of response tovarious loadings. We developed a 3-Dbuilding model of a four-story struc-ture constructed by a DoD program atWhite Sands, NM, using concretecontinuum elements and explicitlymodeled reinforcing steel. The modelcalculations can be used to validatethe code against the upcoming DoDDivine Buffalo test series of thestructure at White Sands.

As a result of the work per-formed under this project, PRONT3Dnow has the capability to analyzereinforced-concrete structuressubjected to blast loading. Combinedwith the massively parallel (MP)

JANUS computer, complete buildingscan be modeled in three dimensions atan unprecedented level of detail tomore accurately predict the response.Additional work should focus oncontinued development of the coupledcode (ZAPOTEC) capability forairblast/structure interaction problemsin general and validation of the codesagainst test data and the implementa-tion of additional enhancements to themodeling of reinforced-concretestructures, such as gravity preloadingand cyclic material response.

We drafted a report describingthe PRONTO3D enhancements thatdiscusses the measured data related tothe behaviors of concrete and rebar,the concrete model, and the elementand material models used to simulatethe response of the reinforcement. Itprovides studies verifying the imple-mentation of the rebar and concretemodels, as well as examples of theapplication of these models. Theenhanced capabilities of the coupledairblast/response code that wedeveloped are also presented. Severalappendices provide further detail forusing the coupled PRONTO3D finite-element (FE) code and the models forpredictive purposes, such as inputinstructions, sample inputs andcalculations, benchmark information,and structural design drawings.

Publications

Other

Attaway, S. W., K. B. Morrill, L. J.Malvar, J. E. Crawford, and R. V.Matalucci. 1998. “Enhancements toPRONTO3D to Predict StructuralResponse to Blast.” Sandia TechnicalReport, in preparation.

Preece, D. S., J. R. Weatherby, S. W.Attaway, J. W. Swegle, and R. V.Matalucci. 1998. “ComputationalMethods for Predicting the Responseof Critical As-Built Infrastructure toDynamic Loads (ArchitecturalSurety).” Sandia Technical ReportSAND98-1240 (June). Sandia NationalLaboratories, Albuquerque, NM.


3530.050

Background RadiationAnisotropy MeasurementSensor (BRAMS)

M. J. Adriaans, R. D. Moyer, P. D.Thacher

The Cosmic Background Explorer(COBE) was launched on November 18,1989, to measure the effective tempera-ture and the anisotropy of the cosmicbackground radiation (CBR). COBE wasa great success, posing many moreastrophysical questions than itanswered. Another mission with muchhigher temperature resolution, flownmuch farther away from the Earth andsun to avoid noise associated withdiffuse solar scattering, is needed. High-resolution thermometer (HRT) technol-ogy offers a unique opportunity forastrophysical radiometry. COBEobserved the large-scale (distance)temperature anisotropy of the CBR andthe microwave background quadrupolemoment of the Universe. These measure-ments, however, were very near thelimits on their thermometry and hencehave large uncertainties. One of thenext-generation missions, PLANCK, aEuropean Space Agency (ESA) missionexpected to launch in 2005, will improvethe temperature resolution to approxi-mately 3 mK, an improvement of abouta factor of 30 over COBE. The tempera-ture resolution and stability of thecurrent, space-proven HRTs is 0.1 nK.These HRTs have already flown on thespace shuttle in the Lambda PointExperiment (STS-52) and will fly againon the Confined Helium Experiment andDYNAMX.

The goal of the BRAMS project isto make use of this very precise ther-mometry in two key areas in astrophysi-cal instrumentation: (1) the develop-

ment of a radiometer for detecting theCBR with a sensitivity of at least 10 nKnear 2.7°K, and (2) the development ofan ultra-stable blackbody calibrator. Wewill test both the radiometer and thecalibrator in a stable, low-temperaturelaboratory instrument. During thedevelopment and testing of theseinstruments, we will also complete aphase A scientific definition study of apossible mission.

Programmatically, we completedinitial studies of technical issues thatwould be important in implementingthis project on a deep space probe,and we studied previous flight experi-ments in this class to determine ourmarket potential.

On the technical side, wedeveloped both PdFe and PdMnmetallic alloys and studied how theirCurie temperature varies with mag-netic concentration. We measured thethermal sensitivity of these newdevices that utilize these new alloys astheir thermometric elements. Westudied these sensitivities as a func-tion of charging magnetic field and as afunction of the metallic ion concentra-tion. We demonstrated a thermalresolution of 0.4 nK in a 1 Hz band-width and at a nominal temperature of2.2°K. This device displayed a drift rateof less than 0.1 pK/second, with a timeconstant faster than 0.6 second. Thesedevices are robust enough to readilysurvive launch, and they are easilymanufactured.

Publications

Other

Moyer, R. D. 1998. “Proposal ofTechniques for Coupling Millimeter-Wave Energy Into Palladium-IronThermometer Rods.” Internal report,Sandia National Laboratories (Febru-ary).

3530.090

Exploitation of SatelliteCommunications Systemsand Networks for IntelligenceApplications

J. E. Heustess

There exists a subset of theintelligence community that is involvedin covert ground–based intelligenceapplications worldwide. These applica-tions are based on small, battery-powered systems that are placed in thefield for long periods of time. Thesesystems require both one-way and two-way world-wide communicationssupport that cannot be supplied byavailable ground–based long-linescommunications networks. Thesesystems require that the communicationslinks be both low-probability-of-detection(LPD) and low-probability-of-intercep-tion (LPI).

These applications include the useof covertly installed electronic sensor/receiver units that collect, process, andexfiltrate intelligence data for analysisand processing. There also exists a classof problems that require data to be bothexfiltrated and delivered to equipmentand systems remotely located world-wide. These systems can include overtand covert tagging and tracking applica-tions, and overt and covert remotemonitoring systems such as unattendedground sensors and remote controlapplications. There are also remotesystems that can interrupt operation ofspecific systems and subsystems atcritical times during national conflicts.

The intelligence communityinvolved in covert, ground–basedintelligence data-collection applica-tions worldwide has continued toshow interest in this area.

We based the applicationsstudied in this project on small,battery-powered systems that can beplaced in the field for long periods oftime. The system defined and designedin the project provides both one-wayand two-way world-wide communica-tions support that cannot be suppliedby available ground–based long-linescommunications networks. The project


shows that the communications linksthat can be implemented have bothLPD and LPI.

This application includes thedesign of a system to support covertlyinstalled electronic sensor/receiverunits that collect, process, andexfiltrate intelligence data for analysisand processing. The project alsodiscusses the class of problems thatrequire data to be both exfiltrated anddelivered to equipment and systemsremotely located worldwide. Thetechnology developed in the reportcan be used to support overt andcovert tagging and tracking applica-tions, and overt and covert remotemonitoring systems such as unat-tended ground sensors and remotecontrol applications. This technologycan also support the implementationof remote systems that can interruptoperation of specific systems andsubsystems at critical times duringnational conflicts.

3530.110

Microcode Evaluation

J. W. Walkup, G. L. Smithberger, E. I.Cole, Jr., J. S. Williams, D. C. Carlson, T.H. Desiena, R. P. Fleming

Having discovered a technique forbreaking or bypassing the cryptographyinvolved in updating microcode for aselected microprocessor, Sandia willmodify the information one bit at a timeand use the in-circuit emulator (ICE)equipment to evaluate any effects onprocessor operation. Although tedious,this will provide a map of the relation-ship between microcode bits andfunctions. With that map, we can selectfunctions that will have the desiredeffect on the overall operation of theprocessor.

We will continue to physicallyevaluate the processor in an attempt tofind the encryption circuitry and themicrocode read-only memory (ROM),random-access memory (RAM), andassociated registers. The technique willagain require ICE, which will repeatedlyload a microcode update. During thedownload, a backside light-inducedvoltage alteration (LIVA) image should

allow isolation of the active section(s)of the processor.

We selected a central processorunit (CPU) type, bought appropriateICE equipment, and investigated themicrocode download techniques, andhave a tool to perform the download atwill rather than simply upon power-up.The tool will also identify the proces-sor and can modify the microcodebeing downloaded to test the effects ofbits being modified.

We characterized and comparedvarious microcode download packagesand can isolate interesting sections ofthe code. We have a workinghypothesis about the encryption usedand believe we can bypass the encryp-tion by using a brute force technique.A demonstration of this technique willbe available as a result of the first yearof this effort.

We are also deprocessing andcharacterizing the silicon die of theCPU to gain an understanding of howthe microcode download works. Thishas not been fruitful because of theextensive metallization on the front ofthe die and will require running testsfrom the back side of the die.

3530.120

Real-Time Image AnalysisUsing Field-ProgrammableGate Arrays

K. J. Jefferson, J. C. Wehlburg, K. R.Lanes, C. L. Grotbeck, A. R. Baeza

Performance and target discrimi-nation requirements for the next-generation remote sensors are drivingdesigns into the hyperspectral regime.Although the mission payoffs for goinghyperspectral are significant, thebandwidth requirements imposed byadditional sensing dimensions areimpossible to meet with availableground links. In addition, the transforma-tion of data into knowledge requiresincreased speed in data processing.These requirements will force next-generation payloads to support on-boardprocessing and event detection. Inaddition, the processing iscomputationally intensive, and for many

types of algorithms, batch processing isthe current choice for mode of opera-tion.

Sandia developed a uniqueconcept for a hyperspectral fast-transientstaring sensor. We will develop ahardware/software solution that willallow us to process imagery in real timeusing a combination of adaptivealgorithms and distributed processingarrays.

Two important problems that needto be addressed in the processing of thedata are geo-location and the extractionof small, moving-target signatures.

We acquired and brought intooperation a basic field-programmablegate array (FPGA) developmentsystem. We developed a simple trialmicroscan algorithm and implementedit in C code as a test for FPGA process-ing. The conversion from C code toVHDL (very high speed integratedcircuit [VHSIC]) is in process. Collabo-rations are in place with researchersfrom the U.S. Air Force. The implemen-tation of a subset of matrix manipula-tions required for thechromotomography is in progress.

We supported a field testrecording transient spectral data fromactual munitions of interest. Werecorded the data with the prototypechromotomography system. Thesedata will be an ideal test data set forour algorithm implementation inFPGAs. That algorithm development isin process now. The architecture for afast-throughput system is emerging.We expect that it will be a combinationof FPGAs and digital signal processors(DSPs). We anticipate demonstration ofan FPGA microscan algorithm appliedto an 8x8 array by the end of the yearand expect to have the appropriatepieces of a chromotomographicalgorithm embedded in an FPGA.

Publications

Other

Jefferson, K. J., J. C. Wehlburg, and A.R. Baeza. 1998. “Real-Time ImageProcessing Using ReconfigurableLogic.” Proc. Mil. and Aerospace Applic.of Programmable Devices and Technol.Conf., accepted.


3530.130

Advanced 3-D Sensing andVisualization System forUnattended Monitoring

J. J. Carlson, D. E. Small, C. Q. Little, J. J.Harrington, C. L. Nelson

The purpose of this project is tocreate a reliable 3-D sensing andvisualization system for unattendedmonitoring. The system will benefitseveral of Sandia’s initiatives, includingnonproliferation, treaty verification,national security, and critical infrastruc-ture surety. The robust qualities of thesystem will make it suitable for bothinterior and exterior monitoringapplications. The 3-D sensing systemwill combine two existing sensingtechnologies in a new way to continu-ously maintain accurate 3-D models ofboth static and dynamic components ofmonitored areas (e.g., portions ofbuildings, roads, and secured perimetersin addition to real-time estimates of theshape, location, and motion of humansand moving objects). A key strength ofthis system will be the ability to monitorsimultaneous activities on a continuousbasis, such as several humans workingindependently within a controlledworkspace, while also detectingunauthorized entry into the workspace.We will use data from the sensingsystem to identify activities or conditionsthat could signify potential surety(safety, security, and reliability) threats.The system could alert a securityoperator of potential threats or could beused to cue other detection, inspection,or warning systems. We will alsodevelop an interactive, Web–based, 3-D

visualization capability using Internettechnologies, Virtual Reality ModelingLanguage (VRML), and JAVA. This willallow remote, interactive inspection of amonitored area (via the Internet orsatellite links) using a 3-D computermodel of the area that is rendered fromactual sensor data.

Our accomplishments includeddevelopments in 3-D sensing, auto-mated sensor calibration, intrusiondetection and monitoring using 3-Ddata, and remote visualization of 3-Dsensor data.

We integrated and modified twoexisting 3-D sensor technologies for aninterior monitoring application. Wedeveloped intrusion-detection algo-rithms to monitor the 3-D characteris-tics of both static and dynamiccomponents. We monitored staticcomponents, including barrels andother physical structures, usingSandia’s Laser Mapper (LAMA)technology. We monitored dynamiccomponents, including humans andother moving objects, by Sandia’s 3-DVideo Motion Detection (3DVMD)technology. We developed a robustsensor calibration procedure tofacilitate setup and application of the3-D sensor technologies. The integra-tion of the LAMA and 3DVMD sensortechnologies allowed us to accuratelydetect changes in the location, shape,and size of both static and movingobjects. We also developed a Web–based, 3-D visualization capabilitybased on the VRML. This Internet–based, 3-D graphical user interface(GUI) allowed remote, interactiveinspection of the monitored area usinga computer model of the area that wasrendered from actual sensor data.

3531.020

System-of-Labs DirectFabrication Technology

M. E. Schlienger

This project is a cooperative effortbetween Sandia National Laboratories,Oak Ridge National Laboratory (ORNL),and the Idaho National Engineering andEnvironmental Laboratory (INEEL). Thegoal of this project is to integrate thedirect fabrication capability at Sandia inlaser-engineered net shaping (LENS™)with the capability at INEEL in spray-forming and the expertise at ORNL innovel materials fabrication and analy-sis.

LENS™ is a laser–based directmanufacturing process that starts with acomputer-aided design (CAD) solidmodel. The model is decomposed into aseries of layers. Each layer is broken upinto a series of raster lines. We use athree-axis system to raster a laser beamalong the resultant lines. We focus thelaser on a substrate, and a molten poolforms. We inject powder into this moltenpool, forming a bead. An X-Y tablemoves the substrate under the LENS™head, and the bead is pulled across theevolving part, resulting in controlleddeposition of metal. As the part buildsup, the LENS™ head is raised one layerin height.

The INEEL spray-forming processsprays molten metal onto a shapedsubstrate to build a part. In the INEELprocess, an RTV negative (a latexnegative) is made from a master part.This mold is used to cast a ceramicform. The ceramic is cured and placedinto the spray-forming device. Moltenmetal is sprayed on the ceramic form,and a deposition builds up. Oncespraying is completed, the part isremoved and excess material is cut off.This process is much faster than LENS™,but shadowing of the metal spray makesthe process unsuitable for high-aspect-ratio features.


The intent of this project is toinvestigate combining these twoprocesses to jointly exploit theiradvantages. ORNL will provide evalua-tion and ultimately custom alloydevelopment in support of this effort.

In the first year, we produced asample part via the spray-form processand added LENS™ features to the part.However, metallographic analysisyielded some interesting data. Perhapsmost important was the fact that theparts from the two processes are verydifferent with regard to their thermalhistories and solidification structure.While LENS™ exhibits a fully dense,rapidly solidified structure, the spray-formed parts were coarser and moreporous. These structures are consis-tent with process observations thatreveal that the entire spray-formedpart glows quite hot for an extendedperiod of time, while the LENS™-produced material glows hot only for afraction of a second. These empiricalobservations clearly indicate a verydifferent cooling rate, as exhibited bythe microstructure. Further, the spray-formed material exhibits dropletboundaries and porosity, where theLENS™ material is fully dense, with noprior powder boundaries. However, inLENS™ the path of the molten poolduring the deposition process isindicated by a variation in grainmorphology that occurs along theprior molten pool boundaries.

Examination of the interfacebetween the two types of depositsrevealed the presence of cracking. Wedid not pinpoint the exact source;however, two theories arose. We basedthe first possibility on the observationof a surface layer on the spray-formedmaterial. The possibility was raisedthat perhaps a contaminant wasembrittling the interface between thetwo deposits. The second possibilitywas that the effect was entirelythermal in nature and that preheatingthe spray-formed part prior to the

addition of the LENS™ deposit couldeliminate the cracking.

These analyses indicated thatalloy development suitable for bothprocesses might be challenging, as thesolidification behavior of the two isvery different. In addition, we decidedthat some further investigation intothe interfacial area between the twodeposits and the mechanism respon-sible for the cracking was warranted.

In the second year, INEELdropped out of the project. Althoughwe obtained no further spray-formedsubstrates, we identified solidificationshrinkage at the substrate/LENS™interface as being at least partiallyresponsible for the cracks we ob-served at this interface. The final proofwill require experiments whereinidentical LENS™ deposits are placedon room-temperature and preheatedsubstrates. Once such deposits havebeen produced, we will evaluate boththe interface and substrate deforma-tion. We assumed that the cracking willbe greatly minimized. We installed ahigh-temperature platen on the newLENS™ machine and on the machinethat has just entered initial stages ofoperation. The experiments indicatedby the results of this System-of-Labs(SOL) project are still of significantinterest and will be completed some-time in the next few months.

The alloy studies revealed thatLENS™-processed H13 had excellentproperties as deposited. The use ofLENS™ as a process for the produc-tion of tooling makes good metallurgi-cal sense. Further, there appears to bean opportunity to fine-tune thecomposition of H13 tool steel to takeadvantage of the rapid solidificationenvironment available within LENS™.

Although no special H13 powdercompositions were produced, ORNLdid provide some nickel aluminidepowder of a proprietary composition.This alloy is a hard, high-strengthmaterial that is difficult to work usingconventional processes. However, with

the LENS™ process, near-net-shapeobjects were produced, and subse-quent testing at ORNL revealedexcellent properties.

Although this project was not assuccessful as we had hoped, weobtained significant useful informationat both ORNL and Sandia as a result ofthis collaboration. This projectcontributed to the substantial progressachieved by the LENS™ process,resulting in current commercializationefforts and implementation of theLENS™ process in the production ofneutron generators.

Publications

Refereed

Griffith, M., M. E. Schlienger, J. Brooks,L. D. Harwell, M. Essien, D. Nelson, andW. Hofmeister. 1998. “Thermal Behav-ior in the LENS Process.” Proc. 9th SolidFreeform Fabrication Symposium 9(Austin, TX, 10–12 August).

Maziasz, P. J., E. A. Payzant, M. E.Schlienger, and K. M. McHugh. 1998.“Residual Stresses and Microstructureof H13 Steel Formed by CombiningTwo Different Direct FabricationMethods.” Scripta Materialia, accepted.

Schlienger, M. E., D. Dimos, M. Griffith,J. Michael, M. Oliver, T. Romero, and J.Smugeresky. 1998. “Near Net-ShapeProduction of Metal Components UsingLENS.” Proc. 3rd Pacific Rim Internat.Conf. on Adv. Mater. and Processing 3(Honolulu, HI, 12–16 July).

Schlienger, M. E., M. Oliver, and T.Romero. 1998. “Sacrificial Materials forComplex Geometry Fabrication.” Proc.9th Solid Freeform Fabrication Symp. 9(Austin, TX, 10–12 August).

Other

Schlienger, M. E., M. Griffith, M. Oliver,and T. Romero. 1998. “Laser-Engi-neered Net Shaping.” Paper presentedto the Automotive Applications ofThermal Spray Technology Confer-ence, Romulus, MI, 3 June.


3531.140

Poco Switch Tubes

G. E. Boettcher

This project will explore designvariations in Poco switch tubes toprovide improved reliability, perfor-mance, and ease of fabrication. Some ofthe initial design features that Sandiawill explore more fully include thefollowing: (1) Probe design: eliminatethe present 6 mil mo nail-head triggerwire, with either cermet or active brazematerial, and evaluate sapphire versus96% alumina trigger ceramics withsmaller inner dimensions (IDs) forenhanced electric field at triggerelectrode, and (2) envelope construc-tion: determine minimum thicknessenvelope height with metallizing bothsides for smaller tubes and providemore self-fixturing features in trigger-cathode design.

(1) We obtained sapphire triggerprobes and evaluated them withdimension, 10 mil outer dimension(OD), 60 mil length, and 3 mil ID, andfound them to be similar in perfor-mance to ceramic probes twice aslarge. We evaluated these small probesin one-kilovolt sprytrons. We fabri-cated five tubes and tested them 100%,and pulse-life–tested two units out totwo-thousand operations to showsimilarity to previous standard designtubes.

(2) We successfully fabricatedand tested 20 mil-thick ceramicenvelopes for a 1000 V dc sprytrontube. We fabricated three tubes; twogood sealed units were 100% testedand pulse-life–tested to failure. Theanode-cathode spacing was 20 mils.Both anode and cathode were palcoflat-facing electrodes with no recess atanode-to-cathode ceramic wall, i.e., 20mil straight-line breakdown path. Onetube failed at 407 operations, and theother failed at 76 operations. Short

pulse life is due to the extremely smallenvelope ceramic that is the tradeofffor the smaller size.

(3) We successfully fabricatedand tested a 0.214 OD sprytron, whichis approximately one-third the size ofthe previous smallest sprytron design.

(4) We successfully fabricatedand tested a probe/cathode sprytrondesign that is self-fixturing.

(5) We showed feasibility forbrazing niobium to sapphire andceramic without metallization requiredand without the use of active brazematerial.

3531.150

Chemiresistors Based onMetal-Loaded Polymers forSolvent Spill Detection

R. C. Hughes

Sandia discovered that small,planar microsensors for solvents can befabricated by mixing common, commer-cial polymers with metal powders likegraphite. Thin films of these compositescan be deposited on interdigitatedelectrodes on an insulating substrate. Anexample of such a film is fabricatedfrom polyisobutylene mixed with 40% byweight of carbon powder. The resistanceof such a film appears to be dominatedby percolation of charge through theconducting carbon particles. Theresistance depends on the number ofsuch contacts and thus on the volumefraction of the carbon particles. Vaporsof some solvents can cause the polymerto swell and thus decrease the volumefraction of conducting particles. Theelectrical resistance thus increases withincreasing solvent vapor pressure. Wewill study this phenomenon. We areparticularly interested in the reproduc-ibility of the sensor signals, as well aslong-term drift in the base (dry) resis-tance. Temperature-dependence of the

signals is also important for an under-standing of the thermodynamics of thepolymer swelling. We wish to understandthe role of entropy and heat of mixingthe solvent vapors in the sensor output.It may turn out that different polymerswill have a sufficiently different re-sponse to various vapors, that arrays ofsensors can be used to identify anunknown vapor by pattern recognition.

We successfully fabricated anumber of chemiresistor sensorsbased on the principle of solventswelling of polymers. We made thesenormally insulating polymers conduc-tive by mixing them with a largevolume of conducting powder, oftencarbon. The conduction is by percola-tion paths through chains of thepowdered conductor, and swelling ofthe polymer increases resistance bybreaking some of the chains. Thepolymer that showed the best behav-ior in terms of speed of response,baseline stability, and reproducibilityof signal over time to many differentanalytes was a copolymer of polyethyl-ene and polyvinylacetate (PEVA). Wewere excited to see that signals fromsome volatile organic chemicals(VOCs) like toluene could be seen withonly a few ppm of partial pressure. Thebaseline stability was so good thatchanges in resistance due to low levelsof analyte of less than 0.1% could bereliably measured over many hours.Other polymers includedpolyisobutylene (PIB),polydiphenoxyphosphazine (DPPZ),syndiotactic polybutadiene (PBS),polyvinylalcohol (PVA), and poly-N-vinylpyrrolidone (PNVP). When weplotted signals from these polymersensors versus the solubility param-eter of a wide variety of solvents, wefound that no solvent goes undetectedby at least one of the sensors. Theseresults confirm our hypothesis that afour- or five-sensor array can be usedas a universal solvent sensor.


3531.160

Advanced Neutron-TubeDesign and Producibility

J. P. Brainard, R. S. Goeke

This work has two goals: (1) todevelop doped insulators to replace anuncontrolled coating process now usedto reduce wall-charging in neutron tubes,and (2) to apply integrated circuit (IC)technology to the production of morereproducible ion sources.

Neutron-tube ion sources contain apatterned metal hydride thin film. Thecurrent fabrication technique uses aphysical mask that is placed in intimatecontact with the source assembly.Correct registration of the mask to thesource substrate is critical. An operatorassembles the source substrate, mask,and fixturing with the aid of an opticalmicroscope. The assembly process istime-consuming and highly dependenton the skill of the operator.

An alternative technique is toreplace the physical contact maskdefinition of the patterned film withphotolithographical processing. Photoli-thography is used in the IC industries todefine features smaller than those on anion source. In this process, we depositedthe film over the entire source assemblyface. We then spun photoresist onto thefilm and defined a pattern by exposureto ultraviolet (UV) light through achrome glass mask. Once the patternwas developed, we could etch away themetal film in the exposed regions,leaving the patterned metal film. Wethen removed the photoresist.

We found that hydrided metalfilms etch very poorly. The MHx materialapparently is stable and resists dissolu-tion. We performed further experimentson pure metal films with the understand-ing that the films would be post-hydrided. We varied etchant concentra-tions and determined etch rates for themetals of interest.

Initial results of patterned metaletching showed severe undercutting ofthe resist pattern by the etchant. Webelieve this to be due to poor adhesionof the resist film to the metal. We arecurrently trying to improve the quality ofthis adhesion.

We began research into the useof IC technology to produce ionsources. This research was slated todetermine if standard semiconductorprocessing techniques can be effec-tively applied to reliably producehydrided metal film patterns forneutron-tube applications. Initialevaluation showed that hydrided metalfilms etch very poorly. The MHxmaterial apparently is stable andresists dissolution. We pursued asecond approach involving furtherexperimentation on pure metal filmswith the understanding that the filmswould be hydrided after formation bythe etching technique. We conducted aparametric evaluation using severalvariables: etchant concentrations andetch rates as applied against variousmetals of interest.

The initial results of the secondapproach, patterned metal etching,showed severe undercutting of theresist pattern by the etchant. Subse-quent evaluation led us to believe thatpoor adhesion of the resist film to themetal is the cause of this unacceptableundercut. We are presently evaluatingadditional techniques to improve thequality of the film adhesion to yieldour desired pattern.

3531.170

Surface Hardening byNanoparticle Precipitationand Atomic Clustering inNi(Al,O)

S. M. Myers, Jr.

This project explores strengthen-ing of the near surface of nickel (Ni) bydense dispersions of hard oxideparticles and atomic clusters in the sizerange from ~ 1 nm downward. Thesedispersions are formed by variouscombinations of aluminum (Al) andoxygen (O) ion-implantation and Al andO ion-diffusion from surface sources inconjunction with heat treatments tomanipulate particle microstructure.Mechanical properties are quantified bynanoindentation coupled with finite-element (FE) modeling, and microstruc-

tures are characterized by transmissionelectron microscopy (TEM). Theorypredicts that the extremely small sizesand separations of the hard particles insuch metal matrices should give rise tonew highs of strength with retention ofductility. Specific objectives of theproject are (1) to probe the limits ofstrengthening that can be reached at theextremes of small particle size and highparticle density, (2) to extend suchhardening to the technologicallyimportant iron-nickel (Fe-Ni) class ofmaterials, and in particular to Nibecause of its anticipated use indefense-related microelectromechanicalsystems (MEMS), and (3) to explorediffusion as an alternative to implanta-tion for nanoparticle-hardening in metalmatrices where the alloying additionsare soluble.

Ion-implantation of O into Ni at aconcentration of 8 atomic percentproduced a yield strength of 5 GPa anda hardness of 14 GPa within the treatedlayer, as shown by nanoindentationtesting combined with FE modeling.Corresponding values for hard bearingsteels extend only to about one-half ofthe above, so that the implantationtreatment has, in fact, achieved a newlevel of strength in the Ni-Fe system.Moreover, the treated layers wereductile and adherent during severedeformation of the specimen surface.

TEM of the above materialrevealed a dense distribution of Al2O3particles with an average size of about2 nm and a volume fraction near 13%within the implanted layer. Applicationof dispersion-hardening theory to thismicrostructure gives a predicted yieldstrength of 5 GPa, in good agreementwith the above experimental result.This serves to validate the theory inthe regime of extreme particle refine-ment and density.

Initial mechanical testing ofNi(Al,O) alloys formed by ion-diffusionof Al and O at elevated temperaturesrevealed strengthening that wassignificant but substantially less thanthat achieved by ion-implantation of Aland O at room temperature. Thisdifference is provisionally attributed toa lesser degree of microstructuralrefinement in the diffused alloy.


3531.180

Dynamical Properties ofPolymers: ComputationalModeling

J. G. Curro

The Polymer Reference InteractionSite Model (PRISM) theory has beenextremely successful in modeling theequilibrium structure and physicalproperties of bulk, amorphous polymers.In this investigation, Sandia will attemptto also use PRISM theory to extractinformation regarding nonequilibriumproperties. In the past, dynamicalproperties such as the glass transitionand viscoelasticity have been correlatedwith the static, equilibrium structure ofthe polymer through the free-volumedistribution. Although the free-volumeconcept has long been useful from aqualitative viewpoint, it has not had aprecise statistical mechanical interpreta-tion. PRISM theory has the ability notonly to provide this fundamentalinterpretation, but also to provide acomputationally tractable modeling toolto compute the free-volume distributionfor polymers at the atomistic level. Inthis project, we would use the PRISMtheory to extract the free-volumedistribution of a range of polyolefinpolymers to test its ability to predictglass-transition temperatures, diffusionconstants, and viscoelastic shift factors.If this approach is successful, themodeling capabilities of PRISM theorywill be greatly extended.

We developed a computationaltechnique that allows one to computethe free-volume distribution of apolymer material from PRISM theory.The cumulative free-volume distribu-tion is defined to be the probability ofinserting a spherical cavity of a givendiameter s into an already-existingpolymer liquid. We found this proba-bility function by integrating the radialdistribution function g(r), obtainedfrom PRISM theory, as the cavity size

was systematically increased from 0 tos. We wrote a computer code toimplement this computational strategyand successfully demonstrated it foran idealized, freely jointed chain modelof a polymer. We also wrote a com-puter code to compute the free-volumedistribution of semiflexible chains witha variable chain stiffness. We per-formed calculations on both freelyjointed and semiflexible chain melts asa function of chain length and chainstiffness. We found that as the chainstiffness increases, the free-volumedistribution becomes narrower andmore sharply peaked at low freevolume.

3531.210

Calculation andInterpretation of the Energiesthat Underlie Transition-MetalSurface Structure

P. J. Feibelman

Recent advances in computerpower and in algorithms for first-principles, electronic structure calcula-tion make it possible to evaluate energyversus atomic arrangement for essen-tially any bonding geometry of anycombination of atomic species. Sandiawill use this power in a systematic effortto uncover basic laws of surfaceenergetics. Using state-of-the-artelectronic-structure methods, we willdetermine the energies and geometriesof fundamental atomic configurations attransition-metal surfaces to a well-defined level of numerical convergence.The results will serve as a standardsystematic foundation for the discoveryand explanation of trends in adatomand vacancy formation energetics,diffusion mechanisms, vibration spectra,molecular-fragment stability, surfacestress effects, work functions, etc. Theywill also provide a reference by which tojudge the range of accuracy of the basic

physical approximations used torepresent the effects of electronexchange and correlation, that is, thelocal density and generalized gradientapproximations.

Surface diffusion by concertedsubstitution (CS) implants adsorbedatoms into a metal’s outermost layer atlow temperatures. Knowing when thisprocess will occur is therefore vital tocontrolling growth morphology. Tolearn the rules that determine the low-T self-diffusion mechanism ontransition-metal (100) surfaces, andparticularly to assess the relevance oftensile surface stress, we performedextensive ab initio calculations. Theresults for Rh (rhodium), Ir (iridium),Pd (palladium), and Pt (platinum)show that the barrier to surface self-diffusion by CS is lower on surfaceswhere the substrate relaxation aroundan adatom and the correspondingenergy gain are greater. For example,on Ir(100) and Pt(100), where CS isknown to be the low-barrier self-diffusion process, lattice relaxationreduces the adatom formation energyby at least 16%. On Pd(100) andRh(100), which favor self-diffusion byhopping, the reduction is 10% or less.On the other hand, the calculationscontradict the notions discussed in thepublished literature that lower-barrierCS corresponds to larger clean-surfaceexcess tensile stress or to tensilestress reduction in the CS-barriergeometry.

Publications

Refereed

Feibelman, P. J., and R. Stumpf. 1998.“Adsorption-Induced Lattice Relax-ation and Diffusion by ConcertedSubstitution.” Phys. Rev. B, submitted.

Other

Feibelman, P. J. 1998. “Are There Lawsof Surface Stress?” Paper presented tothe Conference on Atomic Origins ofStress and Strain at Surfaces, Halle,Germany, 6 June.


3531.220

Interfacial Reactions inCeramic Systems

R. E. Loehman

Understanding and control ofinterfacial reactions are important tomany applications of ceramics. Suchreactions can determine the processingand performance of multilayer elec-tronic devices, sensors, cermets,composites, and ceramic-metal seals.This research seeks to develop afundamental understanding of reactionmechanisms by performing controlledwetting and reaction experiments in ahigh-temperature vacuum furnaceequipped with a quadrupole massspectrometer for atmosphere analysis.Sandia will study reacted specimens byscanning and transmission electronmicroscopy (SEM/TEM) and electron-probe microanalysis. We will modelthermochemistry using the MTDataGibbs energy-minimization code anddatabases.

We studied reactions betweenaluminum (Al) and monazite (LaPO4).We are actively developing monazite asa protective coating for ceramic fibersused in advanced composites. Someproposed compositions use reactivemetals such as Al as a matrix compo-nent. We studied wetting and reactionof bulk LaPO4 by Al at 1200°C. Alreacts by a redox mechanism, creatinga reaction layer of Al2O3. Lanthanum(La) formed in the reaction diffusesinto the residual Al and precipitates onthe grain boundaries on cooling. Thephosphorus (P) formed in the reactionis either gaseous P or AlP that formsporous structures at the interface. Ourpresent analysis cannot tell which is

the case. We concluded that LaPO4cannot be used to make compositesthat contain elemental Al.

In another result we did somewetting and reaction experiments for ayttrium (Y)-Al-silicate glass on alumi-num nitride (AlN). We are developingAlN for components in chemical vapordeposition (CVD) chambers in thesemiconductor industry because of itsexcellent thermal conductivity.However, suitable high-temperaturejoining techniques are not available.Our experiments suggest that the Y-Al-silicate glass may be useful to join AlN.

We also evaluated a refractoryY2O3-Al2O3-SiO2 glass and a gold-palladium-vanadium (Au-Pd-V) alloyfor joining silicon-carbide (SiC)composites. Those continuous-fiberceramic composites (CFCCs) compriseSiC fibers embedded in a SiC matrix.We measured contact angles forsamples of the glass or alloy heated oncomposite coupons from 1200° to1500°C in argon (Ar) or N2. We inferredreactions from analyses of polishedcross-sections of cooled specimens.We joined other specimens forstrength measurements using processconditions determined from thereaction studies. The Au-Pd-V alloy wetall the composites and reacted withthem to give a complex interfacialmicrostructure. Wetting by the glassdiffered strongly with the source of thecomposite, and reaction was less thanwith the alloy. Strengths measured infour-point bending are about 50 MPa,which is much lower than strengthsobtained for these joining materials onother ceramics.

Finally, although preceramicpolymers are finding uses in manyapplications, their interactions withceramic powders and surfaces are not

well understood. Previous workindicated that crystallization of Si3N4from a polymer is affected significantlyby the presence of sintering additives.We studied the effects of temperatureon the interactions betweenpolysilazane, ceramic powders, andadditives. We coated SiN coupons bydipping them in slurries of ceramicpowders, polycyclomethylsilazane,and solvent. After drying, we heatedthe coupons from 1000°C to 1750°C for2 hours to pyrolyze the polymer andcrystallize the derived ceramicmaterials to form a ceramic coating.We examined the resulting microstruc-tures and compositions of the coatingsby electron analytical techniques todetermine mechanisms of pyrolysisreactions and subsequent conversionto the ceramic. In the next phase wewill study interfaces to determine therelation between processing condi-tions, microstructure, and adhesion ofthe coating to the SiN.

Publications

Refereed

Loehman, R. E.; W. G. Fahrenholtz, andJ. J. Walker (University of NewMexico); and J. B. Davis, J. R. Porter,and P. E. D. Morgan (Rockwell ScienceCenter). 1998. “Wetting and Reaction ofMonazite by Al.” Paper presented tothe American Ceramic Society Confer-ence, Cincinnati, OH, 6 May.

Other

Loehman, R. E., S. J. Glass, and B. E.Staley (University of New Mexico).1998. “Interfacial Reactions in theJoining of SiC Fiber-ReinforcedCeramic Composites.” Paper presentedto the American Ceramic SocietyConference, Irvine, CA, 22 October.


3531.230

Direct Fabrication of Multi-functional NanocompositesVia Supramolecular Self-Assembly

C. J. Brinker

The ability to efficiently organizemolecular components at the nanometerscale will greatly influence the future ofadvanced materials in applications forelectronics, catalysis, magnetism,sensors, and mechanical design. Thisstems from the fact that interplay ofstructure, organization, and dynamics atthe molecular level are all vital indetermining a functional response.Based on this premise, Sandia success-fully developed an efficient, continuousprocess to form ordered nanocompositethin films and particles via evaporation-induced self-assembly. We prepared thinfilms by spin- or dip-coating a homoge-neous sol containing alcohol, silicaprecursors, organic monomers, initia-tors, and surfactant (at an initialconcentration [co] below the criticalmicelle concentration [cmc]). Evapora-tion of the alcohol induces the formationof micellar structures that co-organizewith silica to form cubic, hexagonal, orlamellar mesophases. We solvated theorganic monomers and initiators withinthe hydrophobic micellar interiors.Subsequent photo or thermal polymer-ization and washing resulted in a silica/polymer thin-film nanocomposite. Wedemonstrated extension of this evapora-tion-induced nanocomposite self-assembly process to the preparation ofparticles with ordered (vesicular)structures via aerosol processing ofrelated sols. Finally we initiatedsynthesis of polythiophene/silica nano-composites in an attempt to developconductive nanowires isolated in adielectric medium.

We developed an efficient,continuous process to form ordered

polymer containing nanocompositethin films and particles viaevaporation-induced self-assembly.The process starts with a homoge-neous solution of soluble silicates,coupling agent, surfactant, organicmonomers, and initiators prepared inethanol/water solvent with an initialsurfactant co below the cmc. Duringdip-coating, preferential evaporation ofethanol progressively enriches theconcentrations of water, hydrochloricacid (HCl), and the nonvolatilesolution constituents within thedepositing film. As cmc is exceeded,micelles form, causing the spontane-ous organization of inorganic precur-sors around the hydrophilic micellarexteriors and partitioning of alcohol-soluble monomer(s) and initiators intothe hydrophobic micellar interiors.Continued evaporation promotescooperative assembly of these (silica-surfactant-monomer) micellar speciesinto interfacially organized liquidcrystalline mesophases, therebysimultaneously organizing both theinorganic and organic precursors intothe desired laminated structure in arapid (~ 10 s), continuous process.Photo- or thermally-induced organicpolymerization combined withcontinued inorganic polymerizationlocks in the nanocomposite architec-ture and covalently bonds the organic-inorganic interface. Through variationof the surfactant type or its initial co,we can exploit evaporation-inducedself-assembly to arrive at othernanocomposite constructions. We canextend the process to particles withordered (vesicular) structures viaaerosol processing of related sols.Characterization of these materialsshowed that the resultant structurecan be tuned, depending on variablessuch as surfactant type and concentra-tion, humidity during dip-/spin-coating,and substrate preparation. Mechanicaltesting of the layered thin films viananoindentation measurements

quickly demonstrated the added valueprovided by such nanolaminatedconstructions. For example, nano-indentation performed on poly(4-methylstyrene)/silica nanolaminatedthin films prepared with ~ 50 wt.%polymer showed a threefold increasein indentation hardness (from 0.3 GPato 1.0 GPa) due to combined organic/inorganic polymerization. We notedthat 1 GPa is the indentation hardnessmeasured for rather dense sol-gelsilica films. Hence, this material,containing 50 wt.% soft polymer, has asimilar hardness value to that of puresilica films. This enhancement inmechanical properties achieved by thenanolaminated construction is similarto that observed for seashell nacre,composed of alternating layers ofcalcium carbonate and biopolymer. Wemeasured nacre to be two timesharder and 1000 times tougher than itsconstituent phases. We believe thisnanocomposite self-assembly processwill be important for applicationsrequiring hardness and toughnesscombined with optical transparency. Inaddition, by confining polymers tosmall dimensions and reinforcing themon a molecular scale with silica, weanticipate achieving totally newmaterials properties.

Publications

Refereed

Sellinger, A., P. M. Weiss, A. Nguyen, Y.Lu, R. A. Assink, W. Gong, and C. J.Brinker. 1998. “Continuous Self-Assembly of Organic-InorganicNanocomposite Coatings that MimicNacre.” Nature 394 (16 July): 256–260.

Other

Sellinger, A., P. M. Weiss, Y. Lu, and C. J.Brinker. 1998. “Self-Assembly ofOrganic-Inorganic NanocompositeCoatings that Mimic the Structure ofShell.” Hybrid Materials, Proc. MRS 519(San Francisco, CA, 13–17 April): 95–102.


3531.240

Biophotonic Materials forOptical Encryption andNoncomputing

J. A. Shelnutt

The photosynthetic proteinbacteriorhodopsin uses light energy topump protons across a membrane insome photosynthetic bacteria. Theprotein contains a retinal molecule thatexperiences a large-scale, photo-induced, conformational switching thatfunctions as the light-activated protonpump. An analogous optical molecularswitch composed of a more robustnonbiological molecule like a porphyrinhas obvious importance in photonics,microelectromechanical systems(MEMS) devices, and chemLab chipintegration. Sandia demonstrated such anew type of light-activated molecularswitch. We will engineer these newbiophotonic materials to the point whereoptical encryption devices can befabricated using vertical-cavity surface-emitting laser/charge-coupled device(VCSEL/CCD) technologies. We willenhance the optoelectronic properties(lifetimes and light-absorption character-istics) of the molecular switch usingcomputer-guided synthesis of newanalogs. In addition, we will support themolecular switches in polymers for usein photonic and encryption devices. Wewill demonstrate the potential of thesebiophotonic materials for many defense-related and commercial applications

(including ultra–high-density [> 1 Gbyte/cm2] optical memory, ultra-fast [1 ps]optical switching, optical limiting,Q-switching, cavity dumping, modelocking, monolithic optoelectronicintegration, sensor arrays, displays,verification and encryption, andnoncomputing).

We previously demonstrated anovel optical switching method in anickel (Ni) porphyrin. However, thelifetime of the optically switched statewas only 50 nanoseconds at roomtemperature and 6 microseconds atliquid nitrogen temperatures. Our goalwas to utilize the conformationaltrapping mechanism by which theoptical switch works to design a Ni-porphyrin analog in which theswitched-state lifetime is in theseconds-to-years time regime. Wedesigned such a molecule, nickeloctabromo-tetra(trifluoromethyl)-porphyrin, using molecular simula-tions methods and synthesized it. Bythe addition of electron-withdrawinggroups, we introduced a new mecha-nism (axial ligation) for extending thelifetime along with conformationaltrapping. We investigated the proper-ties of the new optical switch byoptical absorption, fluorine nuclearmagnetic resonance (NMR), andresonance Raman spectroscopy, andby x-ray crystallography. Electron spinresonance and femtosecond time-resolved ultraviolet (UV)-visibleabsorption measurements are inprogress. These results indicate thatwe have an optical switch with an

apparent switched-state lifetime ofminutes to months, depending on thetype of molecular support or solvent.We filed a patent on the mechanismsand specific switching materials.

Publications

Refereed

Ma, J. G., M. Laberge, X. Z. Song, W.Jentzen, S. L. Jia, J. M. Vanderkooi, andJ. A. Shelnutt. 1998. “Protein-InducedChanges in the Nonplanarity of thePorphyrin in Nickel Cytochrome cProbed by Resonance Raman Spectros-copy.” Biochemistry 37 (1 February):5118–5128.

Other

Ma, J. G., J. Zhang, R. Franco, S. L. Jia,and J. A. Shelnutt. 1998. “ResonanceRaman Spectroscopy and Normal-Coordinate Structural Decompositionof the Hemes in Cytochromes c3.”Biophysical J. 74 (Kansas City, MO, 22–26 February): A113.

Ma, J. G., R. Franco, S. L. Jia, and J. A.Shelnutt. 1998. “ConformationalDifferences of the Hemes in Cyto-chromes c3 Probed by ResonanceRaman Spectroscopy.” Bulletin APS(Los Angeles, CA, 16 March).

Zhang, J., J. G. Ma, M. Laberge, J. M.Vanderkooi, S. L. Jia, and J. A. Shelnutt.1998. “Nonplanarity of the Porphyrinin Nickel Cytochrome c Probed byResonance Raman Spectroscopy.”Bulletin APS (Los Angeles, CA, 16March).


3531.190

Broadening Mechanism in2-D Excitonic and ElectronGases

E. D. Jones

This research will investigate theorigins for the broadening mechanismsleading to the Gaussian photolumines-cence (PL) lineshapes observed indoped and undoped quantum-well (QW)structures. All homogeneous broadeningmechanisms predict a Lorentzian(lifetime) broadened lineshape, whileinhomogeneous effects lead to Gaussianlineshapes. Experimentally, Sandia willobserve Gaussian PL lineshapes for allsamples, ranging from nearly freeexciton (undoped) systems to dopedstructures exhibiting band-to-bandtransitions at high magnetic fields. Thelatter result is surprising because it isgenerally believed that electron screen-ing in doped systems will smooth out theeffects of varying internal electric fieldsarising from QW fluctuations.

This study will consider the effectsof artificially (or controlled) inducedfluctuations. We will generate fluctua-tions due to varying QW widths bygrowing self-aligned islands indiumgallium arsenide (InGaAs) alloys inInGaAs single-strained-layer QWstructures or by placing InAs quantumdots on the GaAs QWs in GaAs/AlGaAssystems. We can then study the effect ofrandomness by also growing nonaligned(random) islands or quantum dots. Wewill make the same kinds of studies forthe doping layer thickness for modula-tion-doped QWs. The PL lineshapecontribution from deformation potentialfluctuations vis-à-vis the electron-phononinteractions can also be made bydeliberately growing InGaAs alloyclusters formed by low-temperaturegrowth.

We collaborated with research-ers at Emory University in Atlanta, GA,to write an analysis program forstudying the magnetoexciton energy,linewidth, and binding energy for aseries of GaAs QW structures. Thisstudy considered the contributions tothe exciton linewidth in a series of(411)A GaAs/AlGaAs QWs. We alsocollaborated with researchers at theUniversity of California–San Diego forscanning-tunneling microscope (STM)measurements of QW-size fluctuations.We successfully applied our theoreticalmodeling to experimental data ofGaAs/AlGaAs QWs ranging in widthsfrom 0.6 to 1.2 nm. We performed themeasurements at 1.2 K, and themagnetic fields ranged between 0 and13 tesla. We had to modify the theoryto account for conduction-band massnonparabolicity and also a QW width-dependent exciton binding energy.After we made these corrections, wefound good agreement with bindingenergies and magnetoexciton diamag-netic shifts.

3531.250

Low-Stress AmorphousDiamond: A New Material forSensors

J. P. Sullivan, T. A. Friedmann

The purpose of this project is tocreate new types of sensors with greatlyenhanced performance using a newmaterial that Sandia recently discov-ered: stress-free amorphous diamond(a-D). Stress-free a-D is a uniquematerial that has some of the bestproperties of crystalline diamond(extreme high hardness and elasticmodulus, low coefficient of friction, highwear resistance, high toughness, andchemical inertness) together with some

of the best properties of thin-filmmaterials (low and tunable film stress,extreme surface smoothness, ease ofsynthesis, low-deposition temperature,and a robust process for deposition). Bytaking advantage of these uniqueproperties, we fabricated flexural plate-wave (FPW) devices that employ a thinmembrane of a-D (1000 to 1500 ang-stroms thick) as the working element.We also developed a simple, reliableprocessing sequence for the creation ofthese devices, using photolithographi-cally patterned aluminum (Al) lines anda high-density-plasma deep-etch tool (aBosch etcher). The FPW devicesrealized from this process were easier tosynthesize than conventional silicon-nitride (SiN) FPW devices and offergreater promise of achieving highsensitivity and low resonant frequency(important both for controlling theultimate detection limit and for enablingalternative sensor concepts, such asacoustic sensors that work in the audiblerange).

We created and tested a workingsensor, the FPW device, that uses anew material, stress-free a-D. This newmaterial—developed at Sandia—hasmany of the mechanical properties ofcrystalline diamond but the processingadvantages of a thin-film material. Wedemonstrated that it is possible tocreate ultra-thin, free-standing mem-branes in this material that are at leastone inch in diameter and only six-hundred angstroms (approximately300 to 400 atomic layers) thick. Weused several processing sequences tocreate the FPW device. For oneprocessing sequence, an Al meanderline was photolithographically pat-terned onto an a-D film on Si. We thencreated a membrane out of the a-Dmaterial by etching the Si in ananisotropic chemical etch (potassiumhydroxide and water). The secondprocessing approach also used


photolithographically patterned Allines, but we achieved the etching ofthe Si using a deep-etch tool (a Boschetcher). We found that this secondapproach easily and reproduciblycreates the FPW device. We discoveredthat the extreme inertness of a-Dresults in a selectivity to the Boschetch process of 1 in 1000 (in the time ittakes to etch one unit of Si, only1/1000th of a unit of a-D would beetched). This selectivity is far betterthan SiN (about 1 in 75), and thusenables a-D membranes to be synthe-sized that are both far thinner than SiNmembranes and that also are far easierto create. We are developing a techni-cal advance on the use of a-D films asan etch-stop layer for deep-etching.

The FPW devices that wesynthesized have a-D membranethicknesses of 1000 to 1500 angstroms,which is considerably thinner thancomparable SiN FPW devices (5000 to10000 angstroms thick). These deviceshave performance that is as good as orbetter than the best SiN devices of thesame geometry but with the promiseof far exceeding SiN devices (withsmall additional processing improve-ments). Furthermore, the ease withwhich it is possible to create sensorsusing ultra-thin a-D membranesenables new future sensor concepts,such as miniature acoustic sensorswith good response in the low audio-frequency range.

Publications

Other

Sullivan, J. P., T. A. Friedmann, A. J.Magerkurth, M. P. de Boer, M. M.Bridges, and C. I. H. Ashby. 1998.“Amorphous DiamondMicromechanical Structures.” Mater.Sci. of Microelectromechanical Sys.(MEMS) Devices, Proc. MRS (Boston,MA, 2 December).

3531.260

Nanoengineered Cu-AlDefects in Al: A PrototypeSystem for Corrosion

N. A. Missert, J. P. Sullivan

The modeling and prediction ofcorrosion, particularly in metals thatundergo localized corrosion, hasremained elusive despite centuries ofinvestigation. This project will isolateone potential corrosion mechanism inaluminum (Al) alloys by intentionallyfabricating nanoscopic aluminum-copper (Al-Cu) defects in Al with well-defined spatial and chemical properties,then systematically identifying whichproperties of the defect led to the onsetof localized corrosion. This is the firststep in enabling the development ofcomputational codes that can accuratelymodel and predict.

The fundamental scientificquestion to be explored is: How does anAl-Cu precipitate in Al act to initiatelocalized corrosion? Surprisingly, evenfor this one simple defect structure,several mechanisms may be occurringto initiate corrosion: (1) the Al-Cuparticle is more noble than the matrix,(2) the Al oxide that forms over the A1-Cu particle may be defective, and (3)the existence of Cu impurities in the Aloxide may enable high-leakage currentslocally in the oxide. We hope to learn(1) which corrosion mechanism(s) is/are operative, (2) over what size scalesthis/these mechanism/s is/are opera-tive, and (3) what are the electrochemi-cal signatures of this specific defect (sothat the action of this defect can berecognized in a real alloy system). Thiswill ultimately help lead to the develop-

ment of a computational model ofcorrosion.

We achieved arrays of nano-engineered Cu-Al defects on Al thinfilms that dominate the electro-chemical response. Optimized Altemplates for growth of isolated Al-Cudefects are deposited by electronbeam evaporation. Small-grained,random-orientation films provide alow-leakage-current, high-pitting-potential surface for nanofabricationof the Cu defects. We used photo-lithography to define defect sizes of2–50 microns with spacings rangingfrom 10–100 microns. Residual oxide isremoved by argon (Ar) ion plasmaprior to the Cu deposition to allow aclean Cu-Al interface as observed byx-ray photoelectron spectroscopy.Electron beam evaporation of Curesults in large arrays of identicaldefects, which we then subject toelectrochemical testing.

Our initial results indicated thatthe nanoengineered defects areextremely active relative to thesurrounding Al matrix. Under freecorrosion conditions, metastableevents that may be associated with Aldissolution in the vicinity of thedefects dominate the response for timescales up to 4000 seconds. At longertimes, the events cease and the systemachieves a constant potential. The finalstate of the sample shows that the Al isdissolved down to the silicon (Si)substrate in the vicinity of the Cudefect for each defect in the arraystructure. In addition, Cu is dissolvedand redeposited in a halo surroundingthe region of Al dissolution. Clearly thenanoengineered defects are governingthe electrochemical response.


3531.270

Novel Energy-ConversionDevices of IcosahedralBorides

T. L. Aselage

Solid-state devices are commonlyused to generate electrical power fromradiant energy sources. These devicesrely on the incident radiation to gener-ate electrons and holes in semiconduc-tors. The power obtained from suchdevices is proportional to the rate ofcarrier generation and to the efficiencywith which generated carriers arecollected. The rate of generationincreases as the energies of incidentparticles increase. Radioactive decayprocesses yield particles with very highenergies: 105 to 108 eV. Furthermore,radioactive materials are reliable,continuous energy sources. Unfortu-nately, solid-state devices that directlyconvert nuclear energy to electricalenergy using conventional semiconduc-tors are not feasible since these solidsdo not survive bombardment with high-energy particles. Icosahedral borides,however, have been shown to beespecially resistant to radiation damage.In particular, vacancies and interstitialsinduced by bombardment of icosahedralborides appear to spontaneouslyrecombine with one another—self-healing. Thus, bombardment fluxes thatwould severely damage or amorphizeconventional semiconductors produceno observable defects in icosahedralborides. This remarkable observation ofself-healing in icosahedral boridesmakes plausible the successful opera-tion of a device based on these materi-als to directly convert the energies ofnuclear particles into electrical power.

This project explores capitalizingon the self-healing of radiation-induceddamage in icosahedral borides todevelop novel power sources thatdirectly convert the energies ofnuclear particles into electrical power.The goal of the project is to evaluatethe advantages and disadvantages ofvarious radioisotopes for use in such

devices. We identified several attrac-tive radioisotopes.

There are abundant radioactivesources with potential for our devices.These sources differ in the particlesthey emit: a-particles, b-particles, andg-rays. We found b-particle emitters tobe the most promising for directenergy conversion using icosahedralborides. Among radioisotopes thatemit b-particles, differences occur inintensities, half-lives, and the requiredshielding. The source chosen for eachapplication should optimize thesefactors.

a particles are doubly charged,energetic, and penetrate only shortdistances in solids. Despite theseattractive features for direct energy-conversion devices, their accumula-tion within bombarded solids wouldultimately damage the material.Furthermore, a-particle bombardmentof light elements, such as boron (B),generates high-energy neutrons thatpose a substantial hazard. Because oftheir weak interactions, neutronspenetrate long distances throughsolids. For this reason, sources thatgenerate energetic neutrons requireextensive shielding: about 25 cm ofparaffin is required to shield a 1 Wa-particle/b-source.

Even though g-rays createelectron-hole pairs in solids, they arenot attractive for our energy-conver-sion devices because the energy theydeposit per unit distance is very small.Attempting to capture a response fromg-rays would require a very largedevice.

b particles offer the greatestpotential for our energy-conversiondevices. Unlike a-particles, stoppingb-particles within a solid does notdirectly introduce large strain fields.However, some degree of shielding isrequired to attenuate energeticphotons that accompany b-particleemissions. These energetic photonsarise from two sources. First, someb-emitters radiate g-rays from nuclearprocesses. Second, a small fraction ofenergy of the b-particles is convertedto radiation as they are decelerated in

a solid, Bremsstrahlung. Since theintensity of Bremsstrahlung increaseswith the atomic number of the bom-barded solid, the low atomic numberof B is advantageous.

Most attractive b-particleemitters are readily available in thewaste of power reactors. Others maybe produced intentionally in nuclearreactors. The nuclear energy availablefrom selected b-emitters is very large.These capacities range from 1.1 MWper hour per mole of 147Pm (prome-thium) to 25 MW per hour per mole of144Ce (cerium). The half-lives ofattractive radioisotopes vary from 0.35to 30 years. Energy-conversion devicesbased on these sources thus offer thepotential to produce significant,continuous power over extended timeperiods.

Some illustrate examples ofparticular b-decay sources, and theirchoices for specific applications follow.In these illustrations, the lifetime of adevice is taken to be the half-life of theisotope, and the power listed is theinitial power available from the nucleardecay of the pure isotope.

147Pm is appropriate for aminimally shielded, lightweight sourcewhen moderate lifetime (2.6 years) andpower (0.05 kW/mole) are sufficient.170Tm (thulium) is appropriate for ahigh-power device (2.2 kW/mole) thatcan tolerate a short lifetime (0.35years) and moderate shielding. 144Ce isappropriate for a high-power device(3.6 kW/mole) that can tolerate amoderate lifetime (0.78 years) andextensive shielding. 90Sr (strontium) isappropriate for a long-lived device (28years) that delivers moderate power(0.08 kW/mole) and can toleratesignificant shielding.

Publications

Other

Aselage, T. L., and D. Emin. 1998.“Novel Energy Conversion Devices ofIcosahedral Borides.” Paper presentedto the JASON Summer Study, SanDiego, CA, 15 July.


3531.280

Ion-Mobility Spectroscopy ofBiological Materials

P. J. Rodacy, M. A. Butler

The military has used ion-mobilityspectrometers (IMS) to detect chemicalagents for over ten years. Sandiadeveloped IMS for the Federal AviationAdministration (FAA) portal detectorand is using IMS for the detection oflandmines, sea mines, and unexplodedordnance. The only area of IMS that hasnot been pursued is in the detection oflarge molecules such as biologicalagents. To the best of our knowledge, nopreliminary data exist. In addition, theincreasing use of biological agents byterrorist groups mandates betterdetection techniques for these materials,and IMS appears to be one of the primecandidates. This project will allowSandia to maintain our position as aworld leader in all areas of IMS and tobegin responding to an internationalneed for a sensitive, specific biologicalagent detector.

This project demonstrated thatwe could successfully introducebiological materials into an IMS usingan electrospray inlet system and see aresponse. Poor resolution preventedthe identification of individual species.

We designed and built a smallIMS and fabricated appropriate controlelectronics. We performed a series oftests to optimize the system torespond to the long drift times (60 to80 milliseconds versus 5 to 20 milli-seconds normally used) expected ofthese large molecules. By usinginnocuous viruses, we demonstratedthat the IMS responded. However, weobserved a large proportion of thisresponse in the reactant ion behavior,with only a small (indistinct) signalresulting from the parent virus. Webelieved the most likely reason for thispoor response to be (1) poor ioniza-tion efficiency, (2) poor transfer of theviruses through the drift tube, or (3)

instability of the viruses when exposedto the high electrical fields in theelectrospray apparatus. To improvethe IMS response, we used variouselectro-phillic solvents to maximize theionization efficiency, examined thetransfer efficiency through the drifttube, and verified that bacteria (usedinstead of viruses for this test becauseof our ability to grow a culture)showed that the large biologicalmolecules can survive electrosprayingwithout decomposition.

Publications

Refereed

Rodacy, P. J., M. Butler, and J. Sterling.1998. “Analysis of Biological MaterialsUsing Ion Mobility Spectroscopy.”Sandia Technical Report, in progress.

3531.310

Direct Fabrication of PlanarSolid-Oxide Fuel Cells

J. Cesarano, III

Solid-oxide fuel cells (SOFCs) areefficient power sources that are capableof both using a wide range of fuels andavoiding the problems associated withliquid electrolytes. The solid-statecharacter of all the components alsomeans that there are no intrinsicrestrictions on the cell configuration.However, current manufacturing ofSOFCs is very complicated and requiresmany processing steps, which haslimited SOFC fabrication to relativelylarge shapes with simple cylindrical orplanar geometries. Therefore, for SOFCsto be used on a widespread basis andhave their inherent design capabilitiesfully exploited, the fabrication methodsmust be simplified and be versatileenough to process the various compo-nent materials into precise structures.

Sandia will adapt techniquescurrently being developed for directfabrication of ceramics to the fabrication

of advanced SOFCs, which could hencebe used for rapid fuel-cell manufacturingand inexpensive fabrication of minia-ture fuel cells. We based the fabricationtechnique on technology for computer-controlled extrusion of powder slurriesand used this project to demonstratefeasibility for the direct fabrication ofhighly concentrated yttria-stabilizedzirconia slurries.

We completed this project todetermine the feasibility of usingrobocasting technology for the directfabrication of solid-oxide fuel cells.Robocasting is the moldless fabrica-tion of materials by computer-controlled deposition of highlyconcentrated powder slurries. We havealready demonstrated the techniquefor aluminum oxide fabrication. Animportant material for solid-oxide fuelcells is yttria-stabilized zirconia.Therefore, the objective of this workwas to develop highly concentratedyttria-stabilized zirconia slurries thatcould be directly fabricated into denseparts with robocasting technology. Weaccomplished this objective, which isthe first step in creating a capability atSandia for the complete fabrication ofmultimaterial fuel cells in onerobocasting operation.

We made highly concentratedyttria-stabilized zirconia slurries withpowders supplied by Tosoh, Inc. Wewet-milled the powders with polyelec-trolyte dispersants to eventuallyachieve a solids loading that was 54vol.% zirconia. The slurries wererelatively stable with respect tosettling and exhibited a rheologyuseful for robocasting with a syringe.We fabricated solid samples approxi-mately 2 cm x 1 cm x .7 cm thick in amoldless layer-wise fashion. Wedeposited the slurry through an orifice.8 mm in diameter. After completedrying, the samples were 58% oftheoretical density. After sintering, thesamples were completely dense andtranslucent. The measured averagedensity was 99.9% of theoretical.


3531.290

Visualization Tools for MEMSDesigns in a Virtual 3-DWorld

S. L. Miller, G. F. Lavigne, V. R. Yarberry,J. H. Smith

The field of microelectro-mechanical systems (MEMS) is growingrapidly, with great potential to benefitapplications to Defense Programs (DP)as well as commercial partnerships. Themarket for MEMS is anticipated to reach$14 billion by the year 2000. One of thekey barriers to product realization andcommercialization is the lack of designand visualization tools available toMEMS designers. This barrier wasidentified by both the SandiaMicrosystems Roadmap and theCommercialization of MicrosystemsWorkshop. This project will overcomethis barrier by developing a visualiza-tion tool that enables designers to seetheir designs realized in a virtual 3-Dspace before they commit their designsto fabrication.

Presently, Sandia uses AutoCAD asa design and layout tool for MEMS. Thisproduct is an accepted standard formechanical design and includes somevisualization features appropriate forsimple macro structures, but does notinclude the complex features needed fora designer to visualize the intricacies ofcomponents fabricated with MEMS.Imagine a designer being able to explorethe subtle design issues of a MEMS partin the same way that a dust mite canpresently explore a MEMS microengine.

The result of this work will beincreased visualization capabilities forthe designer, which will overcome oneof the key barriers to the commercializa-tion of MEMS and the realization ofproducts in MEMS for DP applications.

We developed a system for 3-Dvisualization of MEMS devices for usewith the Sandia four-layer polysilicon

SUMMiT (Sandia Ultra-planar Multi-level MEMS Technology) process. Thissystem consists of an AutoCAD userinterface and the visualizer code.These codes execute under theWindows NT 4.0 operating environ-ment.

The AutoCAD user interface,written in LISP, provides the MEMSdesigner with a button to initiate thevisualizer. The MEMS designer canselect the initial viewing area. Thecode extracts the mask geometryformed by circles and closed polygons,then creates a hierarchical 2-D geom-etry file.

The 2-D geometry file providesinput to the visualizer. The visualizer,which runs on a PC, converts the 2-Dgeometry to 3-D surfaces based on anextrusion model. This model extrudesthe 2-D geometry using nominaldimensions specified for the SUMMiTprocess. The result is a 3-D surfacemodel that can be viewed by theMEMS designer. The designer reviewsthe structures using a joystick tocontrol elevation and azimuth. Controlof panning and zooming allows thedesigner to fly through the geometryto inspect the simulated structure.This navigation process occurs in realtime.

We translated the standardSandia library of MEMS componentsusing this system. This providesrecallable views of over 40 MEMScomponents. The 3-D visualizer iscurrently available for use in theMEMS Design Lab.

We expect that this new capabil-ity will dramatically increase the MEMSdesigners’ understanding of theSUMMiT design process, reduce designerrors, and improve design turnaroundtime, significantly reducing cost. Thecreation of this design tool will greatlyimprove access to MEMS technologyby both national laboratory andcommercial designers.

3531.320

Micromachining with Ultra-Short Pulsewidth Lasers

D. P. Adams, G. L. Benavides, D. E.Bliss, S. M. Cameron

Numerous technologies critical toSandia require components havingmicron-size features patterned overlarge areas. This includes subminiaturestronglinks, neutron-tube micro-mechani-cal screens, switch tube triggers, and themicroChem laboratory-on-a-chip(µChemLab). However, existingmicrofabrication techniques are limitedin their ability to pattern a diverse set ofmaterials. For example, LIGA (Germanfor lithography, electroforming, molding)is useful for patterning unique 2-Dstructures but is restricted to electroform-able metals. In this work, we intend toresearch ultra–short-pulse laser ablationas a tool for drilling and milling high-aspect-ratio features. Specifically, wewill determine the feasibility of micro-machining a variety of structuralmaterials, such as non-electroformablemetals and their alloys.

This work will explore the use oflasers having pico- to femtosecondpulsewidths. Recent research involvingsingle-pulse drilling demonstrates thatthese lasers are amenable to precisemicromachining of metals, comparedwith conventional industrial lasers. Thequality of ablated patterns improveswith decreased pulsewidth, in partbecause the thermal diffusion length isreduced. As a result, material isremoved more efficiently with littledamage to the volume surrounding afeature (i.e., no large melt zone). Also,the destructive effects of plasmas,


formed over machined holes duringconventional laser drilling, are reducedwhen using ultra-short pulses.

We demonstrated thatfemtosecond-pulse lasers are useful forprecise micromachining of metalalloys. We prepared a Ti:sapphire lasersystem for this project. The apparatusallows for sample ablation at atmo-spheric pressure and under vacuumand incorporates an x,y stage foraccurate positioning of target samples.The optics provide small spot diam-eters of < 20 microns. We ablatedsamples of Kovar using femtosecondpulses of light. In particular, we drilledmultiple holes to different depths toprobe the evolution of hole shape, themorphology surrounding a hole, andtheir dependence on laser fluence. Ingeneral, the material removal ratedepends on fluence and the pressuresurrounding the target. The experi-ments determine that the ablationthreshold for this metal alloy is 100mJ/cm2. Samples drilled in vacuumshow a smoother-edge morphologycompared with samples ablated in air.In this report we also analyze themorphology surrounding holes drilledby other femtosecond-pulse lasers. Incollaboration with the University ofArkansas, we drilled holes in Kovarusing a femtosecond excimer laser.

Publications

Other

Bliss, D. E., D. P. Adams, and S. M.Cameron. 1998. “Laser Machining withUltrashort Pulses.” Paper presented tothe Materials Research Society FallSymposium, Boston, MA, December.

3531.330

Molecular Characterization ofEnergetic Material Initiation

A. M. Renlund, A. S. Tappan, J. C. Miller

Sandia has responsibility for adiverse mix of energetic materials andcomponents. Initiation, reactive wavegrowth, and ultimately deflagration ordetonation depend on chemical andphysical processes at the microscale.The high-explosive HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) isan energetic material used in manyapplications, from actuators to maincharge explosives. Additionally, it isoften used in propellant formulations.We recently discovered that its high-temperature polymorph (designated thedelta-phase) appears to control reactionprogress for thermal initiation. Under-standing the rate of phase transition asfunctions of temperature, particle size,pellet density, and confinement arecritical to predicting cookoff responsefor components and systems. We willdevelop an in situ probe that caninvestigate the HMX phase in confinedgeometries and at elevated tempera-tures. We will rely on both Ramanspectroscopy and second-harmonicgeneration (SHG) that appear possiblewith the delta-HMX. To access confinedgeometries, we will use optical fibers todeliver and return light from the sample.Optimizing the Raman scattering andsimultaneous detection of SHG will bethe main focus of the probe develop-ment. Following development of theexperimental probe, we will examinethe phase behavior of HMX in tempera-ture ranges and confinement pressures

relevant to component and systemcookoff environments. In particular, wewill apply this to monitor the kinetics ofthe phase transition and subsequentdecomposition reactions that lead toexplosive initiation.

In previous work on Ramanspectroscopy of HMX, we observed acurious phenomenon that appeared tobe frequency-doubling of incident laserlight when HMX underwent the beta-delta phase transition. We encountereda variety of problems quantifying theresults, as there appeared to be bothparticle size and density effects.Recently, investigators at Los AlamosNational Laboratory (LANL) indepen-dently observed this phenomenon. Inthe past two months we discussedthese results and will try to investigatethis method of tracking the phasetransition jointly with LANL. Ofprimary importance is the simulta-neous monitoring of the Ramanspectrum and the frequency-doubling.We began literature surveys on SHGaccompanying phase transitions orheating. Indications are that processesother than phase transitions couldaccount for the experimental observa-tions to date.

Publications

Refereed

Renlund, A. M., J. C. Miller, W. M. Trott,K. L. Erickson, M. L. Hobbs, R. G.Schmitt, G. W. Wellman, and M. R. Baer.1998. “Characterization of ThermallyDegraded Energetic Materials.” Proc.11th Internat. Detonation Symp. 11(Snowmass, CO, 31 August), in press.


3532.070

Engineering ComplexDistributed Systems

S. Y. Goldsmith, T. M. Berg, L. M.Napolitano, R. J. Pryor, G. C. Osbourn,B. L. Spletzer, J. T. Feddema, H. E. Link,L. R. Gilliom, S. V. Spires, L. R. Phillips

In this project, Sandia will developa comprehensive design environmentfor the synthesis and analysis ofcomplex distributed systems—inparticular, engineered collectives. Wewill develop the initial fundamentaltheory for modeling, simulating, anddesigning systems composed of distrib-uted autonomous actors with distributeddecision making and control. Suchsystems will be capable of predictablyrealizing important systems-levelbehaviors. The resulting technology basewill provide the basis for controlling thebehavior of tens to millions of intelligentactors, especially robots inhabiting thephysical world and software agentsinhabiting large-scale networks. Throughabstract models and the correspondingsimulations, we will identify the criticalparameters that influence collectivebehavior. We will use the models andsimulations to evaluate relationshipsamong those parameters and tradeoffsthat enable the development of prin-cipled design methods. This project willestablish Sandia as the engineeringleader in emergent and cooperativebehavior and will enable us to becomean important supplier of advancedsolutions to evolving national securityneeds. We will distinguish ourselves byfocusing on the development of this newengineering discipline to enable thesynthesis of sure solutions to real-worldproblems in complex distributedsystems. As such, this project represents

an investment in innovative systemsengineering.

We gained initial insights intocollective behavior and engineeredcollectives. We conducted extensiveliterature surveys in the fields of multi-agent systems, distributed artificialintelligence, statistical physics,information theory, agent architec-tures, communications, and intelligentsystems. We conducted theoreticalinvestigations of collective behaviors,developed models and computersimulations of agent collectives, anddeveloped engineering prototypes ofadvanced software–based networkagents.

Specific accomplishmentsinclude the following:

• Identified the canonicalproblem taxonomy and core technicalchallenges. Explored the congruencebetween the physical and cyber worldswithin the canonical problem space.

• Developed the Alpha-BetaCoordination Algorithm for coordinat-ing teams of mobile robot (alpha-beta).

• Developed a simulator forcollective robotics.

• Developed a multi-agentoptimization algorithm, a new para-digm in optimization.

• Invented a deliberative mecha-nism for software agents.

• Invented an adaptive sensorymechanism for software agents.

• Invented cloning and matingsoftware agents.

• Established collaborations withthe Santa Fe Institute (SFI), Universityof Southern California (USC), Carnegie-Mellon University (CMU), University ofNew Mexico (UNM), and Caltech.

• Completed an initial marketassessment that provided strongsupport for this project.

• Wrote and presented numerouspapers on collective robotics, optimi-zation, agent development systems,and agent theory.

• Submitted three technicaladvances; eleven others are in prepa-ration or identified for preparation.

• Canonical problem articulation.Our principal emphasis was on thesource localization problem. Weinvented and tested in the collectiverobotics simulator a new coordinationalgorithm for controlling a team ofmobile robots, called the alpha-betaalgorithm. Simulated robots, controlledby this algorithm, effectively localize atthe source of a measurable gradient.This algorithm is novel and representsa new approach to collective coordina-tion of robot teams.

We initiated work related to theexploration and mapping problem. Wedeveloped a search strategy for mobilerobots operating in information-poorenvironments that utilizes space-fillingcurves to ensure exhaustive search ofgeographic regions. We also initiatedwork on exploration and mapping inthe purely cyber domain.

We made progress on theadaptive configuration canonicalproblem. We investigated conceptsfrom pattern recognition and classifi-cation to attempt to give individualagents a means to recognize andrepresent emerging global configura-tions in a collective.

In understanding the collectiveproblem class, we conceived a latticemodel of communicating agents basedon statistical mechanics concepts. Ourinteractions with others confirm thevalue of this approach.

• Modeling and simulationenvironment. We investigated severaldifferent approaches to simulating the


behavior of autonomous agentcollectives: (1) an object-orientedsimulator for a team of Robotic All-Terrain Lunar Exploration Rover(RATLER) robots, (2) an object-oriented simulator for collectiverobotics studies of teams of up to 500actors in two dimensions, and (3) asimulator of abstract agents based onprincipals of molecular dynamics.

• Individual intelligent agent life-cycle engineering capability. Wedeveloped a second-generationsoftware agent development frame-work that is based on design reusablepatterns so that its applicability tomulti-agent systems is enhanced. Wedeveloped a second-generation agentwith significant meta-reasoning andcontrol functions that enhance theagent’s abilities to learn and adapt tochanging environments. We incorpo-rated new agent-reasoning functionsinto the development framework. Wedeveloped an initial approach tosoftware agent cloning based on meta-object programming and crypto-graphic digital signature technology.

• System surety approaches. Weidentified and are pursuing fourapproaches to system surety: (1) first-principles design approaches that seekto provide architectural features toenable system surety, (2) formalmethods, (3) risk-management ap-proaches, and (4) principled designmethods based on complexity theory.

Publications

Refereed

Feddema, J. T., and B. J. Dreissen. 1997.“Cooperative Target ConvergenceUsing Multiple Algorithms.” Proc. SPIEConf. on Decentralized Control inAutonomous Robotic Sys. 3209 (Pitts-burgh, PA, 14–17 October): 67–77.

Feddema, J. T., R. D. Robinett, III, andB. J. Dreissen. 1998. “Designing StableFinite-State Machine Behaviors UsingPhase Plane Analysis and VariableStructure Control.” Proc. 1998 IEEEInternat. Conf. on Robotics and Automa-tion (Leuven, Belgium, 16–20 May):1134–1141.

Feddema, J. T., R. D. Robinett, III, andB. J. Dreissen. 1997. “Explaining Finite-State Machine Characteristics UsingVariable Structure Control.” Proc. SPIEConf. Decentralized Control in Autono-mous Robotic Sys. 3209 (Pittsburgh, PA,14–17 October): 46–54.

Goldsmith, S. Y., and H. Link. 1998.“Using KQML to Communicate MutualBeliefs and Shared Goals.” Proc. HICSS’99, Agents Track (Maui, HI, Septem-ber), accepted.

Goldsmith, S. Y., and R. D. Robinett, III.1998. “Collective Search by MobileRobots Using Alpha-Beta Coordina-tion.” Lecture Notes on ArtificialIntelligence, Proc. Collective RoboticsWorld 1998 Workshop 1456 (Paris,France, July): 135–146. Springer-Verlag.

Goldsmith, S. Y., L. R. Phillips, and S. V.Spires. 1998. “A Multi-Agent System forCoordinating International Shipping.”Proc. Agents ’98 (Minneapolis, MN,May): in press.

Goldsmith, S. Y., S. V. Spires, and L. R.Phillips. 1998. “Object Frameworks forAgent System Development.” Proc.Amer. Assoc. for Artificial Intelligence(Madison, WI, June).

Interrante, L. D., and S. Y. Goldsmith.1998. “Emergent Agent–Based Schedul-ing of Manufacturing Systems.” Proc.Agents ’98 (Minneapolis, MN, May).

Kwok, K. W., B. J. Dreissen, and C. A.Phillips. 1997. “Analyzing the Multiple-Target–Multiple-Agent Scenario UsingOptimal Assignment Algorithms.” Proc.SPIE Conf. Decentralized Control inAutonomous Robotic Sys. 3209 (Pitts-burgh, PA, 14–17 October): 111–123.

Spires, S. V., and S. Y. Goldsmith. 1998.“Exhaustive Geographic Searching withMobile Robots Along Space-FillingCurves.” Lecture Notes on ArtificialIntelligence, Proc. Collectives RoboticsWorld 1456 (Paris, France, July): 1–12.Springer-Verlag

Other

Dreissen, B. J., J. T. Feddema, and K. S.Kwok. 1998. “Decentralized FuzzyControl of Multiple NonholonomicVehicles.” Paper presented to the 1998American Control Conference, Phila-delphia, PA, 24–26 June.

Hurtado, J. E., R. D. Robinett, III, C. R.Dohrmann, and S. Y. Goldsmith. 1998.“Cooperative Distributed Agents forOptimization.” Paper presented to theIASTED International Conference onControls and Applications, Maui, HI,August.

Pryor, R. J. 1998. “Developing RoboticBehavior Using a Genetic ProgrammingModal.” Sandia Technical ReportSAND98-0074 (January). SandiaNational Laboratories, Albuquerque,NM.

Robinett, III, R. D., and S. Y. Goldsmith.1997. “Critical Technologies InstitutePresentation: Engineering the Behaviorof Complex, Distributed Systems.”Presentation to the Critical Technolo-gies Institute, White House, Washing-ton, DC, November.


3532.030

Global Approaches toInfrastructural Analysis(GAIA)

D. Engi, T. E. Drennen, K. L. Hiebert-Dodd, D. L. Harris

Our country (and, in fact, theglobal community) is vulnerable tosignificant costs (in both dollars andhuman lives) associated with stressesarising from sources that are bothmanmade (e.g., war, terrorism, andpolitical disruptions) and natural (e.g.,hurricanes, tornadoes, earthquakes,droughts, and floods). There is currentlya need for a comprehensive, integratedsuite of information that would be ofvalue in helping identify opportunitiesfor technological responses to thesestresses. This project is directed towardthe development and deployment of adecision support system (DSS) that willprovide timely, accurate, and high-impact information. The context for thisinformation is the international arenawith an emphasis on the technologicalaspects of responses to these stresses.

This project is motivated bySandia’s recognition that enhancing ournation’s ability to manage vulnerabili-ties of global infrastructures is necessaryto maintain our national security. Werecognize the technical challenges ofcreating an integrated infrastructure DSSand will use a strategy consisting ofarchitecture, process, and metrics toaddress these challenges. We will createan architectural framework to supportthe system, methods for specifyingmodeling and analysis and for integrat-ing new commodities into the system,and metrics for measuring the utility of

the knowledge provided. Integrating thecomputer modeling and simulations ofdiverse commodities, explicitly consider-ing the international arena as thesystem, and combining the judgment ofinternational subject matter experts areinnovations now possible due to theadvent of high-performance computersand the global information infrastruc-ture. This project will require and extendthe expertise from several Sandia corecompetencies and directly addressesSandia Strategic Objectives.

We accomplished three majortasks and produced significant analyticresults. We developed dynamicsimulation models of three significantpolicy options that may be imple-mented to decrease their overallemissions of greenhouse gases,primarily carbon dioxide. We thenintegrated these models into a singledynamic simulation model allowing usto execute the model with varioussubsets of these policies and theirrespective related policy implementa-tion activities. We were thus able tomore accurately model impacts frompolicy activities on greenhouse gasproductions and their impacts onfactors that influence the policycommunity. We decomposed theenergy and greenhouse gas model,which we completed as part of theFY97 work, into a provincial-levelmodel. We executed the provincialmodel to project the provincial energy-use patterns, thus providing a moredetailed description of the anticipatedenergy use. The results of the inte-grated infrastructure model were citedby other sources. We continued toexecute model scenarios and to refinethe model components, primarily inthe policy model subsection.

3532.010

Chemical Feedstocks for theFuture: OxidativeDehydrogenation

N. B. Jackson, J. E. Miller, A. G. Sault

Oxidative dehydrogenation (ODH)is a potential chemical process forproducing olefins such as ethylene andpropylene—the organic chemicals withthe largest production from alkanes inthe U.S. Alkanes are readily availablefrom nature, natural gas, and petroleum,and as major by-products from refineryoperations. ODH offers the advantage ofenergy efficiency and financial savingsover traditional processes. Before ODHcan be used commercially, an active andselective ODH catalyst must first bedeveloped. Sandia is developing anunderstanding of the chemical nature ofthe active surface site that is necessaryto make an economically feasible ODHcatalyst. We focused on the mixed metal-oxide system of molybdenum-magnesium (Mo-Mg) oxide. We pre-pared over 20 different pure and mixed-phase magnesium molybdate catalystsand extensively characterized them forpropane ODH activity/selectivity, phasecomposition, surface area, surfacecomposition, and reducibility. Excitingresults emerged regarding phasesynergies of these materials. We identi-fied a phase or species in the Mo-Mgoxide catalytic system that has an activesite particularly suited to active andselective ODH of propane. We believethere is a high likelihood that we will beable to generalize our observationsregarding the genesis of phase synergiesto several other systems. This discoverycould be crucial in understanding how to


make an active and selective ODHcatalyst. Since 26 billion pounds ofpropene is synthesized from propaneannually in the U.S. alone, this couldhave a profound impact on the industryas well as propel Sandia forward in thefield of catalysis.

We prepared and extensivelycharacterized over 20 different pureand mixed-phase Mo-Mg catalysts forpropane ODH activity/selectivity,phase composition, surface area,surface composition, and reducibility.The activity and selectivity of thesematerials were very sensitive to thestoichiometry and method of prepara-tion. Exciting results emerged tracingthis sensitivity to phase synergies ofthese materials. Mixtures of phases(primarily MoO3, MgMoO4, andMgMo2O7) that are poorly active andselective by themselves interacted toproduce active and selective catalystswhen combined. Heating the combina-tions was often required to bring aboutthe interactions leading to improvedperformance. The catalysts exhibitingsuperior activity and selectivity werecharacterized by a unique tempera-ture-programmed reduction (TPR)peak, centered at about 650°C, thatwas not present for the poorly activeor selective catalysts. Our resultssuggest that the beneficial synergismresults from the formation of a newphase or species rather than throughthe remote communication betweenphases (e.g., by oxygen spillover), as isoften claimed in the literature forsystems of this type.

Results from an x-ray photoelec-tron spectroscopy (XPS)/atmosphericpressure reactor system were inexcellent agreement with the TPRresults. The Mo on the surface of

active catalysts could be substantiallyreduced from Mo(VI) to Mo(IV) bypure propane at temperatures above500°C, while we observed little or noreduction for inactive catalysts.However, when propane and oxygenwere co-fed at typical reaction condi-tions (i.e., 108 Torr propane, 54 Torroxygen at 450°–600°C), we did notobserve Mo reduction for any cata-lysts. This result suggests that ODHoccurs via a Mars–Van Krevelenmechanism on the active Mo-Mgcatalysts. That is, oxygen for thedehydrogenation reaction is providedby the oxide surface (reducing theMo), which is then reoxidized by gas-phase oxygen.

Finally, we observed a previouslyunreported phenomenon for ODHwherein low selectivities occur at verylow conversions, but increase rapidlyas conversion is increased. At thehighest conversions, we observed themore typical ODH behavior of decreas-ing selectivity with conversion.Further studies are required to deter-mine the cause of this unexpectedbehavior.

In conclusion, we developed a“fingerprint” of a phase or species inthe Mo-Mg oxide catalytic system thathas an active site particularly suited toactive and selective ODH of propane.We believe there is a high likelihoodthat we will be able to generalize ourobservations to several other systems.This discovery could be crucial inunderstanding how to create anoptimal active and selective ODHcatalyst. In fact, our experience withODH resulted in two collaborativeefforts with industry being funded byDOE’s Office of Industrial Technology.

Publications

Refereed

Miller, J. E., N. B. Jackson, L. Evans, A.G. Sault, and M. M. Gonzales. 1998.“The Formation of Active Species forOxidative Dehydrogenation of Propaneon Magnesium Molybdates.” CatalysisLett., submitted.

Nenoff, T. M., N. B. Jackson, J. E. Miller,A. G. Sault, and D. E. Trudell. 1997.“Structure-Property Relationships ofBaCeO Perovskites for the OxidativeDehydrogenation of Alkanes.” MRSSymp. Series 497 (Boston, MA, 1December): 100.

Other

Jackson, N. B., J. E. Miller, and A. G.Sault. 1998. “Oxidative Dehydrogena-tion of Propane Using Mixed Phases ofMagnesium Molybdate.” Paper to bepresented to the Spring NationalMeeting of ACS, Anaheim, CA, March1999.

Miller, J. E., A. G. Sault, and N. B.Jackson. 1998. “Studies of MagnesiumMolybdates for Oxidative Dehydroge-nation of Propane.” Paper presented tothe Fall National Meeting of AIChE,Miami, FL, November.


3532.080

Laser CommunicationNanosatellites

J. P. Kern, H. Chang, L. G. Pierson, L. B.Dean, M. D. Baldwin, A. A. Allerman, J.M. Gee, D. Ingersoll, C. T. Sullivan, S. M.Cameron, J. L. Schoeneman

Affordable, reliable, high-band-width global communications willcontribute to increasing, by orders ofmagnitude, the volume of informationavailable for such diverse applicationsas surveillance, missile threat warning,delivering data from unattended groundsensors, and delivery of intelligenceinformation to military field command-ers. DOE has numerous applications forwhich versatile, global, and very highbandwidth communications may beemployed, including monitoring ofmaterials, delivering hyperspectralsurveillance data of potential proliferantor chemical warfare/biological warfare(CW/BW) production facilities, andlinking DOE laboratories, facilities, andcomputing resources into an integratedenvironment, to name a few. Fiber-opticwide-area communications are limitedto terrestrial application and con-strained by geographical availability.Low Earth-orbiting (LEO) communica-tions satellites can overcome theselimitations. Furthermore, they canovercome the physical limitations ofoptical fiber and, with fewer nodesbetween geographical locations, reduceswitching delays that further limitavailable capacity. Finally, the utiliza-tion of space–based lasers, rather thanradio frequency (RF), as the communi-cation media has the advantage ofsuperior bandwidth availability.

Dozens, even hundreds, ofsatellites are required for globalcoverage at low Earth altitudes. For sucha system to be affordable and reliable,the cost of satellites and launches mustbe drastically reduced, and challenges inthe control and exploitation of thishighly distributed communicationsatellite network must be overcome.Miniaturization and mass production ofhighly integrated nanosatellites will bekey to reducing satellite costs. Miniatur-

ization will also allow mass launches ofa dozen or more satellites, furtherreducing system costs. The problem ofnumerous cooperating mobile communi-cations nodes will require the principlesof distributed processing and distributednetwork architectures to be adapted andapplied.

• Laser communication/photonics/optics. The laser communi-cations and photonics task developedthe Optical Phased-Array SteeringSystem (OPASS) concept, which canenable fine-pointing accuracy for laserintersatellite crosslinks, with thepotential for substantially reducinggimbal weight needed for beamsteering, and can correct for systemdefocus caused by unavoidable solarand thermal-loading effects. Wedesigned and are currently fabricatingOPASS devices for a 4X4 2-D steeringproof-of-concept using Sandia’sphotonic integrated circuit (PIC)technology.

We also applied state-of-the-artmicrofabrication technology to theproblem of dramatically reducing thevolume needed to hybrid-packagedissimilar materials (silicon [Si],gallium-arsenide [GaAs], indium-phosphorus [InP]) in a high-density,wafer-scale, stacked multichip module;we achieved passively self-alignedinterlocking Si die with ± 5-microntolerance and accurately positionedmicrolasers into etched Si wells.

• Satellite power systems. Satellitepower subsystems traditionallyconsist of three elements: (a) energyconversion (photovoltaics), (b) energystorage (batteries), and (c) powermanagement and distribution. Incurrent satellite systems the powersubsystem alone can constitute up toone-third of the overall weight of thesatellite; hence, it can be a key limitingelement in any space mission, and infact is one of the main limiting ele-ments confronting implementation ofthe nanosatellite concept. To over-come these limitations, we initiateddevelopment work in three areas.

(1) A four-junction solar cellhaving a theoretical efficiency of 40%.Work toward the four-junction solar

cell focused on developing a novelcompound semiconductor material(InGaAsN) that is essential in realizingthe high theoretical efficiency. Wedemonstrated the other materialsrequired for the four-junction cell.

(2) Advanced Si microstructures(diffractive optics) that could signifi-cantly enhance end-of-life performanceof Si solar cells. We demonstratedcreation of enhanced optical absorp-tion diffractive optical structures in Siusing reactive ion etching.

(3) Advanced lithium-ion batterythat will increase specific energy andenergy densities. We designed andfabricated a 28 V battery pack with anenergy density of 115 W h/kg andspecific energy of 221 W h/l.

• Advanced manufacturingtechnologies. An alternative castingtechnique is under development inwhich a filled hollow mold is with-drawn from a molten pot of metal tofabricate complex thin-walled struc-tures. We developed a high-thermal-conductivity shell system; designed,assembled, and tested a withdrawalsystem for the 500-pound vacuum-induction melting (VIM) furnace;prepared initial bar molds; establishedinitial casting parameters; and gener-ated and tested mechanical testsamples. Finally, we fabricated acomplex part to demonstrate theviability of the process.

• Satellite constellations/network-ing. We conducted theoretical andsimulation studies of possible Nanosatconstellation geometries. This resultedin four unique new concepts varying incomplexity and amount of coverage/redundancy. We also completedstudies for power-saving designs as apassive up-/downlink and a unidirec-tional laser link. To simplify on-satellitecomplexity, we completed and docu-mented development of a geographicaladdressing and simple routing proto-col concept. Further explorationprovided the uniqueness of minimumlatency communications in LEOconstellations as a critical nationalsecurity asset to be further cultivated.We studied 64-byte datagrams forasynchronous transfer mode/interface


protocol (ATM/IP) regarding source–based routing concepts for use insatellite constellation networking.

• Laser communications throughEarth’s atmosphere. Laser opticalcommunication potentially offerssignificant advantages for remotecoordination and covert dataexfiltration from distributed ground-sensing networks. A major weaknesslimiting the operational utility ofnonideal optical communicationchannels propagating in atmosphere,however, has been adverse effects ofextinction (loss), scattering (disper-sion), turbulence (degraded coher-ency), and fade, which degraderealizable transmission bandwidth andgain aperture for acceptable bit errorrate. For this task, we investigated theuse of a previously developed activeimaging technique based on opticalparametric amplification (OPA) toenhance detector sensitivity and errorrate performance for unguidedcommunication links affected byclouds and turbulence. Using aneyesafe kilohertz repetition ratefemtosecond laser system, we evalu-ated the role of signal-spontaneousOPA beat noise, amplified spontaneousemission (s-ASE) on amplified signal,noise figure, bit error rate, andchannel-sampling capacity for variousmodulation formats in both direct andcoherent detection modes to establishfundamental limitations on realizabletransmission bandwidth as a functionof turbidity.

Publications

Refereed

Chen, H. Y., J. Hutchins, B. Mah, and J.Naegle. 1998. “A Lightweight, Link-Layer, Source–Based Routing Protocolfor LEO Satellite Networks.” Proc.NanoSpace ’98 Conf., accepted.

Other

Dean, L. B., J. G. Peña, L. G. Pierson,and H. T. Chang. 1998. “NanosatCommunications Network Develop-ment.” Internal Quarterly Review forCenter 5700 (24 August).

3532.130

Accelerator Technologies forEmerging Threats

B. N. Turman, S. M. Cameron, J. C.Wehlburg, J. F. Wagner, G. M. Loubriel,C. L. Olson, M. G. Mazarakis, S. L.Shope, J. A. Jacobs

Pulsed-power accelerator tech-nologies offer the potential for high-energy projection at great distances,with the possibility of use for directdestruction, disruption, and decontami-nation on the conventional battlefield orthe nonconventional urban environ-ments of terrorist attacks. With recentaccelerator and pulsed-power technicaldevelopments (such as the CollectiveIon Accelerator, compact high-intensitypulsed-RF sources), this capability maynow be brought to bear on the problemsof newly emerging threats of the 21st

century, such as biological agent attackand detection of terrorist bombs, mines,and unexploded ordnance (UXO). Ofparticular interest and importance is theuse of high-energy, high-intensity beamsfor projecting energy and radiation overextended ranges for neutralization ofbiological weapons. Based on thecurrent U.S. standards for commercialradiation sterilization of medicalproducts, the dose level required forneutralizing biological organisms isabout 1 Megarad. These radiation levelscan be produced with state-of-the-artpulsed-power accelerators, as well ascommercial industrial accelerators.Accelerator systems are shown to befeasible for mobile ground–baseddecontamination. Locating and eliminat-ing UXO and combating terrorism arepossible using MeV-energy backscatterx-ray imaging (BXI) to detect buriedUXO. Sandia identified key technologiesand development requirements, includ-ing compact accelerators, compactlightweight power sources, and beampropagation and control.

This study identified a number offuture emerging-threat militaryrequirements and capabilities thatcould be met effectively with accelera-

tors and pulsed-power technology. Thethreat of biological warfare, andparticularly the threat posed byterrorist attack, is an area of highpriority for the nation and the worldtoday, and this is a problem in whichan accelerator–based radiation sourcecould be of immense importance. Theresult of our preliminary analysisshows that we could use commercialaccelerator technology to develop aradiation-producing system that wouldprovide large-area decontaminationfrom biological agent release. Theexample system would be based on RFLinac or Rhodatron accelerator design,with an average beam power of 50 kW.The radiation generated by the beamupon impact with target surfaceswould be the decontaminating/neutralizing effect. We would accom-plish beam scanning by conventionalmagnetic scanning techniques. Weenvision a remotely operated system.Demilitarization of stockpiled weaponsis also a possibility with a high-energyelectron beam and x-ray converter. Weevaluated the concept of an accelera-tor–based system for intercepting anddecontaminating an incoming war-head. While this application haspotential, the technology is notcurrently available and will requiresignificant future development.

Also of importance for futuremilitary and environmental applica-tions is use of low-energy back-scattered x-rays for location of buriedobjects. Extension of this technique toMeV level energy, and combined withground-penetrating radar (GPR), couldgive significant enhanced capability formine detection and location of UXO.The x-ray system, scaled at 6 MeVenergy level, could give excellentdetection and imaging of the near-surface environment, down to a depthof about 0.5 m. The GPR would givedeeper subsurface imaging for deeplyburied ordnance. The two systemswould be relatively easy to integrateand merge imaging data. Therefore,this hybrid detection system is worthyof further development and demon-stration.


3532.090

Collection and DataSynthesis of AtmosphericExplosion Ground Truth forGlobal Monitoring Systems

M. B. Boslough

Sandia is in the process ofcollecting and interpreting ground truthdata for the October 9, 1997, superbolideexplosion over El Paso. ComprehensiveTest Ban Treaty (CTBT) infrasoundinstruments observed the event from LosAlamos, at the correct azimuth and witha preliminary yield estimate of about 0.5kiloton. This energy release correspondsto a magnitude that recurs only onceevery few years in North America. Thefrequency of occurrence over a majorcity like El Paso–Juarez is thereforequite low, and we hope to extract asmuch useful information as we can fromthis circumstance. The location of thisevent near a city provides an opportu-nity to independently assess the accu-racy and precision of the CTBT monitor-ing system.

We collected seismic, videotape,still photo, and other data on a fieldexpedition to El Paso. The burst locationthat we constructed based on grounddata is several kilometers away from thepoint on the satellite trajectory, bothvertically and in the horizontal plane.We expect to confirm the final ground–based trajectory by the recovery ofmeteorites

The primary reason for us tocontinue and follow up our field work isthe apparent discrepancy betweensatellite and ground truth. The CTBTcommunity needs to know the limita-tions of the satellite data, and thedifference needs to be explained.

Our project was twofold: to (1)characterize the October 9, 1997, ElPaso bolide and compare to CTBTdata, and (2) prepare to collect groundtruth for future events.

On October 9, 1997, at ~ 18:47:15UT (local noon), a large fireballdetonated east of El Paso. Mostresidents of El Paso and Ciudad Juarezheard the blast, and many watched the

resulting dust clouds. The fireball castdiscernible shadows on this cloudless,clear day; it was bright enough to beobserved by persons inside curtainedrooms. The flash exceeded - 20magnitude, making it a superbolide(> million times brighter than a normalfireball). Witnesses under the burstlocation described the landscapeturning red. A security camera systemrecorded the secondary shadow castby the event.

The terminal explosion was 31.80N, 106.06 W at ~ 28.5 km altitude, welllocated by eyewitness reports, videos,and photographs of the dust cloud andseismic records. We analyzed 18photographs and 6 video recordings,one that includes the sound. Thefireball was visible and audible forseveral hundred kilometers. Visualrecords were taken between 2 and ~ 20minutes after the event; the cloud wasperceptible for ~ 40 minutes. Thedisintegration of the projectile resultedin a chain of puffs between 35 and 28.5km altitude with a near ~ 1 km spheri-cal cloud from the terminal blast.Streamers continued past the terminalexplosion, but photographs suggestthat most of the projectile was pulver-ized. Wind shearing of the puffsdestroyed their linearity within ~ 5minutes. The shearing is consistentwith upper wind data recorded nearbyearlier that day, confirming the derivedaltitude for the terminal burst.

Infrared (IR) satellite systems,seismographs, and infrasound detec-tors recorded the event, allowingintercalibration to atmosphericexplosions. The satellite detectionfixed five active stations. The provi-sional calibration of energy released toinduced ground motion (3.3 X 1010 J/nm for 58 km distance) derived for theSt. Robert (Quebec) fireball is sup-ported by preliminary data. Seismicsolutions from the El Paso regionindicate average velocities of ~ 305 m/second for the loudest audible arrivals.Although a single relatively compactground-shaking boom dominated thesound, the audible energy lasted ~ 20seconds (for observers within ~ 40km), and the subaudible signal ~ 35

seconds. At Los Alamos NationalLaboratory (LANL), two infrasoundarrays maintained as part of the CTBTmonitoring system recorded the event.The signal lasted ~ 4 minutes at this~ 450 km distance with a 0.2–0.8 Hzfrequency range and maximumamplitude of 21 microbars. An energyrelease equivalent to ~ 0.5 kilotons wasindicated.

The trajectory was within 20° ofan S-N azimuth, with an elevation angleof ~ 65°. Radiants within this rangerequire entry velocities of ~ 25 km/sfor objects from the middle of theasteroid belt (~ 2.5 AU) consistent witha projectile having an initial mass of 5to 10 tons for the observed energyrelease. The deep atmosphericpenetration suggests a strong stonyobject, but the large entry velocityresulted in disintegration of most ofthe projectile, thereby suppressingmeteorite delivery. Any meteorites fellin terrain that is relatively favorablefor meteorite recovery. This falloccurred 11 hours prior to the nodecrossing for the fifth anniversary of thePeekskill H6 chondrite fall on October9, 1992, but the trajectory is wellenough known to exclude a Peekskillradiant.

We developed and built about adozen all-sky video cameras and are inthe process of deploying them inseveral arrays. The primary pilotarrays are in the Albuquerque area andthe Pacific Northwest. Several smallfireballs have already been recorded,and we are in the process of develop-ing software tools to determine thetrajectories of fireballs recorded onmore than one camera.

Publications

Other

Hildebrand, A. R., P. Brown, D.Crawford, M. Boslough, E. Chael, D.Revelle, D. Doser, E. Tagliaferri, D.Rathbun, D. Cooke, C. Adcock, and J.Karner. 1998. “The El Paso Superbolideof October 9, 1997.” Paper presentedto the 1998 Hypervelocity ImpactSymposia (Extended abstract),Huntsville, AL, 16–19 November.


3532.110

Advanced RadiationSources: Rayleigh-TaylorMitigation Via PerturbationReduction

R. B. Spielman, M. R. Douglas

Sandia will increase the overallefficiency of z-pinch plasma radiationsources by reducing the effect of thedominant magnetohydrodynamic (MHD)instability, the Rayleigh-Taylor (RT)instability. In particular, we plan toinvestigate the source and the magni-tude of the density perturbations in theinitial plasma sheath both experimen-tally and computationally. Theseperturbations seed the RT instability.Calculations suggest that modestreductions in the level of the initialperturbations (2.5% to 1.25%) couldincrease the radiated x-ray power fromz-pinches by 2X or equivalently allowthe present level of performance fromlonger implosion times, thereby reducingpulsed-power driver requirements.

We plan experiments to study theevolution of plasmas in z-pinch configu-rations. The measured evolution of theplasma will be modeled at Sandia usingtwo- and three-MHD codes and the latestresistivity and equation-of-state (EOS)models.

We divided tasks into two parts:the experimental portion and therelated computational tasks. Theexperimental work is being carried outin collaboration with the University ofNevada–Reno.

We are building up the experi-mental capability to explore theevolution of z-pinch plasmas from theinitially cold, solid-state condition.This means that we must have a largecurrent delivered to the load in ~ 100ns and sufficiently accurate plasmadiagnostics to measure the density andtemperature with spatial and temporalresolution.

We designed and built opticaland x-ray plasma diagnostics.

The computational and modelingwork is under development. Wedeveloped tungsten, copper, and steelresistivities models and are tabulatingthem for ALEGRA and MACH2. Theseresistivity and EOS models are criticalfor any z-pinch calculations. We aretaking great care to ensure the maxi-mum accuracy of the models.

ALEGRA 2-D MHD with radiationtransport is now up and running, andwe have begun 2-D ALEGRA calcula-tions. Single-wire calculations usingthe tabular SESAME resistivities andEOSs have started. We tested the 3-DALEGRA capabilities without radiationtransport and are testing this modelingcapability with single- and multiple-wire configurations.

3532.120

Microfluidic Engineering

P. H. Paul

A new class of microfluid deviceshas been uncovered that offers a uniqueopportunity to develop new microscaleactuation, control, and thermofluiddevices. Sandia determined thatelectroosmotically driven flow of anelectrolytic fluid as contained in amicroporous medium can yield veryhigh pressures (hundreds of atmo-spheres) at flow velocities of mm/s. Thisability to transform electrical power intohigh-specific-force mechanical motion ina microscale device offers the ability tocreate microscale actuators at the waferscale. Traditionally, microelectro-mechanical systems (MEMS) haveemployed electrostatic motors (or lineardisplacement engines) that providerapid deflection rates but at a very lowforce. To achieve force levels requiredfor useful actuation, electrostatic driversrequire a large gear train to convert thismotion to small displacement at high

force. The electrokinetic pump (EKP)provides a means to convert electricalpower directly to force levels suitable foractuation. An EK system is essentially amicrohydraulic device that allows theEKP action to be delivered at a distanceusing capillary interconnects, hence thename fiber hydraulic system (FHS).The FHS is the work analog of a fiber-optic system, i.e., the communication ofwork (information) at a distancethrough a fused silica capillary (fiber-optic) link. The ability to pump fluidsefficiently and at high pressure inmicroscale systems also offers theopportunity to develop microscaleliquid-cycle heat pumps that would becapable of operating at much higherheat fluxes than conventional Peltierdevices.

We experimentally characterizedthe basic physical properties andresponses of an EKP and developed apredictive model. Parametric testingincluded responses to variations in theworking fluid (permittivity andviscosity); electrolyte pH, composi-tion, and conductivity; and pump hostmicrogeometry, pore size, and mate-rial. We measured general engineeringperformance characteristics, includingpressure generation, flow rate, andpower-conversion efficiency. Wecreated a set of basic engineeringdesign rules. The demonstratedperformance of these devices suggeststhat EK fluidic systems can contributeto a broad range of areas. EK actuatorscan provide microvalves, pumps, andmixers; robotic systems, where EKPscan be employed to drive miniaturelinear and rotary motors; new meth-ods of vehicle drag reduction, wherearrays of EK pumps in the skin of thevehicle can be used to modify thelaminar sublayer; surety devices,where EKPs offer the high specificforce required to drive miniaturizedstrong links; and advanced miniaturepassive and active heat-transfersystems.


3532.150

InGaAsN: A Novel Materialfor High-Efficiency SolarCells and Advanced PhotonicDevices

A. A. Allerman, D. S. Walsh, D. M.Follstaedt, S. R. Lee, S. R. Kurtz, J. M.Gee, J. F. Klem

Increased deployment of satellitesfor communications and surveillanceapplications has led to explosive growthin the demand for high-efficiency solarcells to power these platforms. Today’ssatellites are increasingly power-hungry,since on-board power capacity directlytranslates to mission capability. Inresponse to this demand, compoundsemiconductors have revolutionized thespace photovoltaic (PV) business overthe last five years by offering higher-efficiency solar cells than achievable bycompeting technologies. Their successcomes through the use of bandgapengineering to build multilayer struc-tures tailored to efficiently convertphotons from different bands of the solarspectrum into electricity. While thisapproach led to two- and three-junctiontandem solar cells with efficiencies of22%–24%, further advances were limitedby the range of bandgaps obtainablewith conventional III–V compoundsemiconductor alloys composed ofaluminum, gallium indium, arsenide,and phosphorus (Al, Ga, In, As, and P).In a recently applied-for joint patentfrom Sandia and the Air Force ResearchLaboratory (AFRL), we identified a wayto introduce small amounts of nitrogeninto the Group-V mix to create a newclass of compound semiconductors ofthe type InGaAsN. The small percentageof N, with a correspondingly smallpercentage of In added to maintainlattice-matching, significantly lowers thematerials bandgap, thereby opening upconsiderable new flexibility for bandgapengineering of new photonic devices inaddition to higher-efficiency PV.

We are developing multijunctiontandem solar cells as power sourcesfor satellite systems operating in airmass zero (AM0) solar radiation. TheInGaAsN alloy system appears ideal forthis application. Nitrogen incorpora-tion has proven problematic and achallenge to demonstrate high-qualityInGaAsN (N > 0.02) epilayers neededfor solar cells. We report on proper-ties, growth, and performance ofInGaAsN solar cells. We demonstratedinternal quantum efficiencies > 70% for1.0eV bandgap solar cells.

We grew InGaAsN films bymetalorganic chemical vapor deposi-tion (MOCVD). Unintentionally dopedInGaAsN was p-type. We achievedn-type material using SiCl4. We grewlattice-matched films at 600°C and 60Torr using a V/III ratio of 97, a DMHy/Vratio of 0.97, and a TMIn/V ratio of0.12.

We observed a significantincrease in photoluminescence (PL)intensity from these films following apost-growth anneal. The PL intensitywas a maximum for samples annealedfor either 700°C for 2 minutes or 650°Cfor 30 minutes.

The optical properties of theInGaAsN films were extremely sensitiveto N content, ex situ annealing, anddoping. In addition to the bandgapreduction, there was PL quenching inInGaAsN films with increasing Ncontent. We did not observe a band-edge PL peak in as-grownIn0.07Ga0.93As0.98N0.02 films at300°K. After the ex situ annealingprocess, we observed a band-edge PLpeak, approximately 60 meV linewidth,in our p-type films. Annealing hadnegligible effect on the absorptionspectra of the p-type films. Deep-leveltransient spectroscopy (DLTS) resultsshow that annealing eliminates amidgap defect state present in our as-grown material. N-type doping with Siappears to introduce yet anotherdefect. With Si doping, the band-edge

PL was weak both before and after exsitu annealing. Also, the absorptionspectrum for the Si-doped materialdisplayed a low-energy tail.

The solar cell described in thiswork consisted of a 1.0 µm-thick,n-type (2x10e17cm-3, Si-doped)In0.07Ga0.93As0.98N0.02 emitter grownon a 1.0 µm-thick, p-type (4x10e16cm-3)base. A 50 nm-thick, Al0.8Ga0.2Aswindow layer and a 0.15 µm-thick GaAscap/contact layer (both n-type,5x10e18cm-3) were grown on top of thesolar-cell emitter. We applied noantireflection coatings to the 0.25cm2

cell.Solar cell spectral response

extended out to the band-edge of theInGaAsN at 1.2 µm. We obtained peakinternal quantum efficiencies of > 70%for the annealed cell. Annealingimproved the quantum efficiency byroughly a factor of five over as-growncells. Comparing the performance ofour thick n-type emitter solar cell withthin n-type emitter cells, we found thatnegligible electron diffusion is occur-ring in the 1.0 eV p-type material(annealed or as-grown). To date, wehave obtained high quantum efficien-cies only with cell designs utilizinghole diffusion in n-type material.

Previously, InGaAsN solar cellsdisplayed short minority carrierdiffusion lengths, and their photocur-rents were dominated by electron-holepairs generated in the depletionregion. The highest internal quantumefficiency reported for an InGaAsNsolar cell was = 60% (@ 1.1 µm),achieved with a compensation-dopedp-i-n device. Conventional p-n InGaAsNsolar cells displayed internal quantumefficiencies typically < 25% (@1.1 µm).

To estimate the minority carrierdiffusion length in our cells, wemeasured the photocurrent responseversus bias. The photocurrents of theannealed and as-grown cells displayedroughly the same dependence ondepletion width, although the photo-


current was much larger for theannealed cell. From our modeling andabsorption data, we estimate that thehole diffusion lengths are 0.6–0.8 µm(annealed) and 0.2–0.3 µm (as-grown).The improved efficiency of ourannealed InGaAsN cell was due todiffusion of holes in the n-type emitter.

Annealing decreased the satura-tion current from 1.1x10e-6A/cm2 (as-grown) to 8.3x10e-7A/cm2 (annealed).Similarly, the diode ideality factor (n)approached unity with annealing.(n=1.21 annealed versus n=1.33 as-grown). As bandgap energy increased,we found that the open-circuit voltagerapidly increased.

We grew and designed anInGaAsN solar cell with improvedperformance. Unlike previous cells, wedemonstrated viable minority carrierdiffusion and realized > 70% internalquantum efficiency.

Publications

Refereed

Jones, E. D., A. A. Allerman, and S. R.Kurtz. 1998. “PhotoluminescenceStudies of InGaAsN/GaAs SingleQuantum Wells.” Oral presentation tothe 4CF98 Meeting of the AmericanPhysical Society, Los Angeles, CA,March.

Kurtz, S. R., A. A. Allerman, E. D. Jones,J. M. Gee, J. J. Banas, and B. E.Hammons. 1998. “InGaAsN Solar Cellswith 1.0 eV Bandgap, Lattice Matchedto GaAs.” Appl. Phys. Lett., submitted.

Other

Allerman, A. A., S. R. Kurtz, E. D. Jones,J. M. Gee, J. C. Banks, P. C. Chang, J. J.Banks, and B. E. Hammons. 1998.“InGaAsN for High-Efficiency Multiple-Junction Solar Cells.” Presentation tothe DOE/BES Next-Generation TeamMeeting, Denver, CO, 11 September.

3532.160

Technologies for CounteringC/B Terrorism

G. A. Thomas, B. L. Haroldsen, W.Einfeld, D. C. Roe, R. G. Schmitt, P. K.Falcone

The threat of chemical/biological(C/B) terrorism is as diverse as thetechnologies required to combat it. Theproblem space spans from initialdetection of the threat through predictingthe consequences to mitigating theconsequences. The thrusts of this effortaddress all three facets of the problem:

(1) Development of an ultraviolet(UV)-microchip laser for application incompact biodetection systems. Onecritical component in any practical,fieldable sensor for bio-agents is the UVexcitation source. In this project, Sandiaseeks to design, build, and test diode-laser–pumped, passively Q-switchedmicrolasers with nonlinear frequencyconversion to produce UV wavelengthsneeded to build a fieldable biomaterialsensor.

(2) Innovative physical validationtechniques for C/B transport and fatemodels. The development of computersimulation tools must be accompaniedby model validation efforts. In thisproject we intend to explore the abilityof recent developments in syntheticaperture radar (SAR) to produce high-resolution, subscale, physical models oftypical U.S. urban locales, such as theWashington, DC, mall or downtownChicago, and, in a wind or water tunnel,generate a set of data that describes howtoxic agents disperse throughout the citylandscape. These data will be directlyapplicable to numerical code validation.

(3) Computational molecularrecognition (CMR) tools for antiviral/antitoxin development. The ability todevelop highly effective drugs for masstreatment of casualties following a

domestic biological warfare (BW)release can be significantly enhanced bythe use of computational tools. We willdevelop CMR tools in this effort.

(4) In situ destruction of C/Bagents before release. The ability toneutralize terrorist devices in situbefore agent release is of prime concernto the domestic response community. Wewill develop a percolating hydrothermaloxidizer, a.k.a. batch incinerator, as aportable system for on-site deviceneutralization.

• Development of a UV-microchiplaser for application in compactbiodetection systems. We developedand characterized a microchip laserthat produced UV light in the correctwavelength region (260–360 nm), hadacceptable output energy (50–100microjoules), and was capable ofpulsed operation in the desiredfrequency range (100 Hz).

• Innovative physical validationtechniques for C/B transport and fatemodels. We completed a survey ofavailable wind tunnel testing facilitiesand the sensors required for modelvalidation. We constructed a simplemodel using available SAR data.

• CMR tools for antiviral/antitoxindevelopment. We developed a func-tional framework for the CMR toolsthat incorporated several modeldomains from physical interactionsincluding electrostatic and van derWaals forces, molecular dynamicsinteractions involving conformationalfolding, to quantum effects. Weintegrated some simple chemical/physical models.

• In situ destruction of C/B agentsbefore release. We developed a scaleprototype percolating hydrothermaloxidizer and initial tests to evaluatepotential performance.

A supplemental task to evaluatestrategic threats to U.S. targets fromC/B terrorism resulted in an initialstudy being completed.


3532.140

Technologies for System-Level Innovations in BallisticMissile Defense

C. T. Sullivan, S. M. Cameron, R. K. King,W. W. Tarbell, S. Y. Goldsmith

The proliferation of ballisticmissiles is an emerging threat to U.S.national security; rogue nations arerapidly acquiring ballistic missilesystems that can potentially deliverweapons of mass destruction (WMD)(such as nuclear, chemical, or biologicalweapons) against U.S. allies andmilitary forces. The U.S. is faced withresponding to this crisis on severallevels. The military needs better sensors(typically hidden in protective sanctuar-ies such as tunnels, bunkers, etc.) thatsee or detect the presence of ballisticmissiles. After weapon detection,military planners need better methods tohelp them quickly formulate a battlemanagement plan (gleaning informationfrom multiple sources) to deal with thethreat. Finally, the military needs themost effective means to destroy themissile assets, preferably while they arestill in their protective structures or theboost phase of launch. Early destructionsignificantly reduces the burden ofterminal missile defense.

• High-sensitivity lightwavemodulation for enhanced satellite–basedsensing. We measured an on-chip lossof about 9 dB and a Vp of about 3 V,compared to the predicted values andgoals of 3 dB and 1.2 V, respectively.Neither packaged fiber-to-fiberinsertion loss nor electroopticalbandwidth was measured because thebasic unpackaged Mach-Zehndermodulation (MZM) did not meet ourexpectations. We believe two effectsmay have compromised the deviceperformance. First, an intermittentelectrical contact along the electrical-

optical interaction length can causelower sensitivity than predicted andhigher optical loss by scattering. Athin dielectric scum that formed underour Schottky contact during thedielectric isolation step may havecaused this. Second, we observedanomalously high losses in the signalarm of the MZM for sample EA0300,which degraded our extinction ratio topractically zero and increased our lossby > 6 dB. Numerical modeling for thesomewhat idealized device geometrydoes not adequately explain this effectas yet, and it may not be able to do soif the source of the loss is a layerresulting from chemical reactionsbetween the semiconductor and itscontact metals. Changing or eveneliminating the dielectric isolation stepand increasing upper cladding thick-ness in the waveguide can solve bothproblems.

• Atmospherically compensatedlaser vibrometry for remote detection ofground motion. This work establishesthe viability of an optical parametricamplifier (OPA)–based, self-referenc-ing, laser speckle shearing interferom-eter as a sensitive means to detectsurface vibrations, even in the pres-ence of an intervening scattering layer.The instrumental sensitivity to surfacedisplacements overlaps with thepredicted range for vibrations due toheavy machinery operated in anunderground structure. The OPAtechnology can be integrated with astandard lidar platform and is compat-ible with active multispectral sources.

• Agent–based C2 systems.Military C2 places requirements on anagent architecture that cannot be metwith current technology. Significantinvestments in R&D are required toenable agent–based C2 on a scale thataddresses real C2 problems. Thischapter provides a technical visionand the technical elements of agent–

based C2. We did not complete devel-opment of a prototype system.

• Development of a detonator forhard-target fuze applications. This workshows promise for improving theshock survivability of HNS(hexinitrostilbene) using inert bindermaterials. The candidates considereddemonstrated a marked increase in thestatic crush strength over pellets madefrom the raw material. We expendedconsiderable effort in developing aviable design to incorporate thesemiconductor bridge (SCB) slapperinto a configuration capable ofsurviving the harsh environmentassociated with hard target penetra-tion. Future work will study the effectsof high-intensity shock loading on thecandidate binder-HNS compositions.We will perform a series of thresholddetermination tests to assess thedegradation in sensitivity incurred as aresult of using the binder formulations.We will compare these results tosimilar data from the untreated HNSmaterial.

• Technologies for suppression ofenemy ballistic missiles through boost-phase intercept (BPI). Based on thiswork, it is unlikely that any technologyinvestment in sensors or interceptorswill ever turn these concepts into long-range (> 100 km) systems. Havingreached this conclusion, there are stillinvestments that can make thesesystems all that they can be for short-to medium-range intercepts.

Publications

Refereed

Cameron, S. M., S. Y. Goldsmith, R. K.King, J. L. McDowell, C. T. Sullivan, andW. T. Tarbell. 1998. “Innovations inBallistic Missile Defense (BMD).”Sandia Technical Report SAND98-2328(October). Sandia National Laborato-ries, Albuquerque, NM.


3532.170

Aerosol Stand-Off DetectionTest-Bed

R. P. Toth

A validated requirement exists forport and airbase survivability underbiological warfare (BW) attack. Thebasis of this survivability is earlyindication and warning (I&W) fromsensors for BW agents. Two concepts arepossible: (1) an array of point sensors,or (2) a stand-off sensor. The first optionhas many defects, e.g., data communica-tions and pattern analysis are needed toconfirm BW attack. This means asignificant area is subject to unprotectedattack before a valid I&W is issued.Stand-off sensors clearly provide anattractive alternative.

Our radio-frequency (RF) disper-sion analysis concept is attractivebecause of near-real-time reporting,viability determination, detection ofmicroencapsulation, and potential toclassify BW threat at the level of Genus.

We collected pilot data for vectornetwork detection of aerosol invarious RF regimes in the aerosol test-bed. The aerosol has a narrow disper-sion around a nominal 1 micron. Weconfirmed the hypothesis that phase

of scattering parameter S21 parallelsaerosol production in the transmissionelectron microscopy (TEM) cell. Thus,measurement of electrical path lengthis the indicator of sensitivity. Aspredicted, the magnitude of S21 isinsensitive, as are both real andimaginary components of S11. We arenow confident that a bistatic configu-ration of the stand-off sensor is theonly workable method.

With respect to sensitivity, weare limited by the 0.25-degree phaseresolution of the vector networkanalyzer plus the physical path lengthof the TEM cell. These set the sensitiv-ity of the test-bed. We note that at 345MHz for the first 100 ml of aerosol inthe TEM cell, phase shift is about 0.75degrees. We detected a 1.8 mm changein electrical path length. This is animpressive result! To scale to 30 MHz,the TEM cell would need to be about12 times longer. This suggests that asmall-scale, free-space experiment maybe the next step before dispersionanalysis for microcapsules.

We produced the following keyresults:

(1) Confirmed the stand-offsensor system design concept as abistatic RF sensor.

(2) Confirmed the hypothesisthat the phase of complex scattering

parameter S21 is the most sensitivemeasurement method.

(3) Confirmed the hypothesisthat the time course of change incomplex scattering parameter S21 islinearly related to the time course ofaerosol production at three frequen-cies.

(4) Demonstrated aerosoldetection sensitivity in the test-bed bydetection of as little as 1.8 mm changein electrical path length.

Publications

Refereed

Larsen, L. E., and R. P. Toth. 1998.“Stand-off Sensor for Microencapsu-lated Micro-Organisms.” AerosolDetection Test-Bed Report to Sandiaand DOE (January).

Other

Larsen, L. E., and R. P. Toth. 1998.“Stand-off Sensor for Microencapsu-lated Micro-Organisms.” Invitedpresentation to CBDCOM, Albuquer-que, NM, January.

Larsen, L. E., and R. P. Toth. 1998.“Stand-off Sensor for Microencapsu-lated Micro-Organisms.” Invitedpresentation to DSWA, Arlington, VA,January.


3532.180

Design and Optimization ofHigh-Power ElectromagneticSource Systems andEngagement Scenarios forAchieving Functional Upsetor Damage in Specific TargetElectronic Systems

R. C. Pate, J. F. Aurand, L. F. Rinehart, P.E. Patterson, P. J. Federico, S. B. Dron, P.D. Coleman, D. J. Riley

Modern electronic systems arevulnerable to upset or damage fromelectromagnetic (EM) attack, especiallyin the form of narrowband and short-pulse wideband, high-power microwave(HPM) radiation. It is in the best interestof both the DOE and DoD to be aware ofour national vulnerabilities to HPM as athreat and, at the same time, to betterunderstand and optimize the capabilityof HPM technology as the basis foreffective nonlethal weapons systems foruse against specific classes of tacticaland strategic targets. Key to the assess-ment of HPM both as a threat to nationalassets and as the basis for usefulweapon systems for specific applicationsis the development and validation ofquantitative models and methodologiesfor systems characterization, engineer-ing analyses, and optimization, takinginto consideration the entire ensembleof target set configuration and suscepti-bilities, HPM source system design andperformance, engagement scenarios,and defensive countermeasures.

This project seeks to integrate thebest available target susceptibility data,HPM weapon system modeling, andmission planning to conduct first-orderdesign and optimization of HPM weaponsystem configurations, operationalrequirements, and target engagementscenarios to achieve successful targetupset or damage in two specific hypo-thetical cases of interest. This willprovide an initial framework andmethodology to more systematicallyevaluate the HPM threat to nationalassets, design and optimize HPMsources and engagement scenarios foruse against specific selected targets,evaluate the effectiveness of defensive

countermeasures, assess the complete-ness and consistency of availabledatabase information, and identifyspecific key areas where further work isneeded.

This project focused on estab-lishing analysis procedures andconducting classified systems engi-neering feasibility and design/perfor-mance trade-off studies involving theapplication of candidate high-powerEM source technology options againstselected specific electrically vulner-able target systems.

Our approach was to first selectspecific targets of particular interestand assess their effects on a suscepti-bility threshold. We then chose anappropriate and practical range ofcandidate source technologies, basingmode, and engagement scenarioparameter space for use in conductingsource system design and perfor-mance trade-off studies to achieve adesired effect in conjunction with eachspecific target selected. The candidatesource technologies, basing mode, andrange of engagement parametersselected also resulted in the imposi-tion of certain practical constraints onallowable source system size, weight,and physical configuration. Con-straints on source size and weightsubsequently impact the estimatedcapability and performance availablefrom each candidate source systemdesign.

We based target system vulner-abilities to a candidate EM sourcethreat based on the specific engage-ment scenario under consideration,the radiated output pulse spectrumexpected for the candidate sourcetechnology, the dominant energy-coupling paths/mechanisms expectedinto the target, and the identificationof critical target system component(s)expected to have the greatest suscepti-bility. We undertook specific targetcomponent vulnerability thresholdanalyses that made use of existingavailable information and someadditional experimental data acquiredduring the project on damage suscepti-bility thresholds for key component(s).We then combined componentsusceptibility thresholds with

expected EM coupling path attenua-tion to yield estimates of the incidentEM-pulse field strength, or effectiveradiated power density, for a givenduration required on-target to achievethe desired effect.

Estimates of the power densityon-target (Pt) required to achievedesired effects, combined withengagement scenario information onthe range (R) from the source to thetarget, allows one to calculate theeffective isotropic radiated power(ERP) output required of the source.The basic relationship is ERP =(4*PI*R**2)* Pt, where R is the rangein meters, Pt is the on-target powerdensity in watts per square meter, andERP is in watts. For a given operatingfrequency, the ERP is simply related toactual source parameters by ERP = Ps* G, where Ps is source output powerin watts and G is the total effectivesource antenna gain (dimensionlessquantity).

For a given operating frequency,the total effective antenna gain term(G) is proportional to the cross-sectional area of the radiating antennastructure. Conversely, the outputbeamwidth (which dictates thepointing accuracy required) of thesource for a given frequency isapproximately inversely proportionalto the linear dimensions (e.g., width ordiameter) of the antenna structure.The output power of the source (Ps)depends on the output stage operatingvoltage, impedance, and effectiveradiation output efficiency for theparticular type of source technologyunder consideration. Moreover, wefound the required input energystorage, power throughput capacity,size, and weight of the overall sourcesystem to depend on the details of thecandidate source system technology,physical configuration, and operatingefficiencies required to achieve thedesired target effects within thephysical constraints imposed by thebasing mode and engagement scenarioparameters selected for the analyses.

Based on the above, we did alimited set of source system designand engagement performance trade-offstudies for specific target and scenario


parameters selected. Operationaltradeoffs involved analyses of therelationships among estimated sourcesystem size, weight, pulse shape/length, pulse repetition rate, pointingaccuracy, and command/controltiming required to achieve the desiredradiated power and energy on target atvarious ranges for the most appropri-ate source technology options. We alsoincluded general risk assessment.Leading choices emerged from thestudies for source system technologiesand configurations best able to meetthe requirements for achieving thedesired effects with the least risk forspecific selected combinations oftarget, source basing mode, andengagement scenario.

Publications

Other

Pate, R. C., P. D. Coleman, S. B. Dron,and M. T. Buttram. 1998. “FeasibilityStudy on the Design and Optimizationof High-Power Electromagnetic SourceSystems for Achieving Desired Effectson Specific Target Systems UnderSelected Engagement Scenarios.”Sandia Technical Report (classified). Inpreparation.

3532.190

Real-Time Design ofImproved Powder PressingDies Using Finite-ElementMethod Modeling

K. G. Ewsuk, A. F. Fossum, J. G.Arguello, Jr.

We will apply and expandSandia’s extensive expertise in powdercompaction science and technology todevelop a user-friendly computer codethat incorporates agile features to designcomplex geometry dies for powdercompaction faster and more economi-cally. This advanced technology willprovide considerable advantages indesigning and manufacturing advancedceramic components, including (1)reducing manufacturing costs, cycletime, and waste, (2) enabling more cost-effective manufacturing of specialty

components and small lot sizes, (3)reducing component development time,and (4) maximizing design and manu-facturing flexibility (i.e., design andmanufacturing agility). A successfulproject will significantly impact efforts todesign and manufacture advancedceramic components with improvedperformance and reliability for weaponssystems, including cermets and leadzirconate titanate (PZT) voltage bars forneutron generators. The ultimate goal ofthis project is to develop a finite-elementmethod (FEM) computer code thatmaterials and design engineers caneasily use on a commercial platform(i.e., ABAQUS) to systematically designand rapidly develop functional dies forpressing ceramic components fromgranulated powders.

We met all of our technicalmilestones: (1) determined realisticmaterials parameters/variability forFEM modeling to design powdercompaction dies, (2) developed anagile FEM computer code with variablematerials and geometric parameters todesign complex geometry dies forpressing powder compacts, (3)established a dedicated workstationfor die design/compaction simulations,and (4) successfully tested FEMmodeling capability/code to designcomplex geometry dies. We also arelooking into the possibility of patentingthe concept we used to design thetemplates used in the computer code.

We set out to prove a conceptthat we could develop user-friendlycomputer code to simulate compac-tion using existing Sandia FEM codeand compaction expertise and a newconcept that involves a uniquetemplate architecture. We devised aunique concept to design a variabledimension and parameter templateand demonstrated that this concept isa valid one to develop a user-friendlycompaction code. We used this code todemonstrate 3-D compaction simula-tion capability whereby one can build/design a die on the computer in realtime and define the compactionconditions simply by responding tostraightforward questions from thecomputer screen. We used the newcode to simulate the compaction of a

complex geometry part (e.g., abushing) fabricated by companies wecollaborate with on a CooperativeResearch and Development Agreement(CRADA). Of significant note is thesimplicity with which the die designand compaction simulation can nowbe completed and at significantlyreduced time. When we originally ran asimilar simulation under the CRADA, ittook about 2 weeks to set up thecomponent geometry and mesh-up thepart to complete the FEM compactionsimulation on the computer, and ittook another 8–12 hours to run thecompaction simulations. With the new,user-friendly, template–based code, anon-expert is now able to set up andmesh the part geometry in about 5minutes, and the compaction simula-tion can be run in 20 minutes. Wereduced the total time from weeks tominutes to design a die and run acompaction simulation. With thetemplate–based code developed, wedemonstrated the inherent flexibilityto systematically change the die designto simulate mechanical compaction ofalmost any axisymmetric cylindricalcompact geometry imaginable (i.e., ofcurrently manufactured ceramiccomponents). The new template takes1000 steps to run the compactionsimulation, and we made a movie ofthe densification of a bushinggeometry to demonstrate the newcapability.

We anticipate that this computa-tional technology can be used as adesign tool to reduce or eliminate dieand/or component prototyping, savingmuch time and expense in productdevelopment and commercialization.This is particularly important inadvanced ceramics manufacturing, asceramic components are typicallymore expensive to manufacture thaneither metals or polymers (i.e., thistool will allow ceramic componentmanufacturing to be more cost-competitive with other materials). Thecomputer template also is a tool thatwill be valuable in designing andmanufacturing small-lot-size specialtyparts (e.g., cermets and v-bars forneutron generators for DefensePrograms [DP]).


3532.210

Development of Fiber-Laser–Based LIF for Detection ofSO2

D. A. Kliner

Current understanding of manyaspects of the Earth’s climate system islimited by the available data. Measure-ments of critical species and processesare required to gain a detailed andquantitative understanding of past andpresent climates, to assess and narrowthe uncertainties in climate models, andto develop the predictive capabilityrequired to discern natural and anthro-pogenic influences on the future climate.Providing such measurements requiresdevelopment of new diagnostic methodsfor key atmospheric species and theirincorporation into chemical sensors withhigh sensitivity, specificity, and timeresponse. Sandia will develop these newchemical-sensing capabilities.

The species we will target initiallyare oxides of nitrogen and sulfur,specifically NO and SO2 (sulfur dioxide).These molecules play a central role inthe Earth’s climate, and anthropogenicactivities (primarily fossil-fuel combus-tion) are the dominant source of bothspecies. Existing measurement methodsfor NO and SO2 lack adequate sensitivityand/or time response to address manyoutstanding questions in studies of theEarth’s climate.

We will explore the use of single-mode fiber lasers (developed for opticaltelecommunications) as compact,lightweight sources of tunable, narrow-bandwidth, deep-ultraviolet (UV)radiation. We will also perform spectro-scopic studies to optimize laser-inducedfluorescence (LIF) for detection of NOand SO2 with high sensitivity andspecificity.

We performed two types ofexperiments: (1) spectroscopic studiesof SO2 to optimize the LIF detectionscheme, and (2) development of acompact fiber laser for generation ofnarrow-bandwidth, UV radiation.

We measured absorption,fluorescence-excitation, and dispersedfluorescence spectra of SO2 at pres-sures of 7–700 Torr (the range relevantfor detection throughout the atmo-sphere) with the bath gases N2 and O2.We tuned the excitation wavelengthbetween 210 and 220 nm and detectedfluorescence from 210 to 400 nm. Wemeasured quenching rates for twoabsorption bands.

We determined the optimumexcitation wavelength to be 216.9 nm(alpha2(0,5) band). The optimumdetection wavelength is ~ 230 nm, andthe detection bandwidth should be> 10 nm. Pressure broadening onlyslightly reduces the peak absorptioncross-section of the 216.9 nm band,and the baseline is well resolved evenat the highest pressures (on-line/off-line contrast ratio of 6/1 at 700 Torr).The sharp features present in the low-pressure fluorescence spectrum arebroadened at elevated pressure, butthe overall shape of the spectrum doesnot vary significantly with pressure,thereby simplifying the calibration ofthe LIF detection scheme. Radiativedecay, predissociation, and collisionalquenching make comparable contribu-tions to the depopulation of electroni-cally excited SO2; the LIF sensitivitytherefore varies with pressure, and themeasured quenching rates are neces-sary for calibration of the detectionscheme.

Future experiments will investi-gate quenching of electronicallyexcited SO2 by H2O and the tempera-ture-dependence of the quenchingrates.

Development of a portable, LIF–based SO2 sensor requires develop-ment of a compact source of tunable,narrow-bandwidth, UV radiation. Weperformed initial development of sucha source in collaboration with theNaval Research Laboratory (NRL).Specifically, we built and tested a Q-switched (pulsed), Yb-doped fiberlaser pumped by a high-power diodelaser. The gain medium consisted of asingle-mode optical fiber whose corewas doped with 2.5 wt.% Yb3+ ions. Wesurrounded the core by a multimodecladding into which we launched ~ 200mW of 974 nm pump radiation. Thelaser cavity included a Faraday mirrorto compensate for the birefringence ofthe fiber, thereby ensuring linearoutput polarization (necessary fornonlinear frequency conversion). Weaccomplished wavelength tuning withan angle-tuned dichroic filter (1060–1090 nm). We used a standard Pockelscell as the Q-switch.

The laser system producedpulses of 5 ns duration and up to 2.0kW of peak power at a repetition rateof 1–5 kHz. The power consumption(electrical) was < 1 W. The UV wave-lengths required for LIF detection ofSO2 are accessible by frequency-quintupling of this source. Futureexperiments will entail implementingthe nonlinear conversion scheme andfurther characterization and optimiza-tion of this new laser system.

Publications

Other

Kliner, D. A. V., J. P. Koplow, L.Goldberg, and R. L. Farrow. 1998.“Laser Development and Spectro-scopic Studies for Development of aNew SO2 Sensor.” Sandia TechnicalReport, in preparation.


3532.220

Penetration and Defeat ofHardened UndergroundFacilities Using a MicroholeDrilling Robot

D. J. Holcomb, E. H. Ahrens

There is an increasing need toattack buried, hardened targets that arebeyond the reach of conventionalpenetrators because of their depth orhardening, or both. As the physicallimits of materials for penetrationdepending on kinetic energy areapproached, it is time to tap theenormous technological base that existsin the drilling industry. Drilling 100meters into rock is trivial using conven-tional technology. The nontrivial task isdoing this with a package that cansurvive in a hostile environment. Theessence of Sandia’s work was to analyzethe application of available technologiesfor cutting small (2–5 cm) holes in rockat very high rates. Many of the size,weight, and power requirements forconventional drilling arise from the needto apply high thrust and torque to the bit.The new technologies require neither.The combination of small hole size andlow-thrust, low-torque cutting means thatthe apparatus can be made very smalland light. Our goal was a system sizedto fit a conventional penetrator bodythat would carry the drilling robot belowthe surface, making discovery anddestruction of the system unlikely duringthe estimated one hour required to drillto the target.

We identified two enablingtechnologies, DTHH (down-the-holehammer) drilling and the use of anaero-bic OTTO fuel (OTTO is the inventor’s

first name), that make it possible toconstruct a drilling system that is smalland light with penetration rates pre-dicted to be as high as 5 meters/minute.Experts prepared and reviewed systemdesign in drilling, penetrators, lethality,and OTTO fuel, and found it to befeasible, if difficult. Advances in thepredicted rates of penetration reopenedthe possibility of a surface-landedsystem that would need only 15–20minutes to drill into the facility.

Our goal was to determine ifavailable or near-term-availabletechnologies were sufficient to allowconstruction of a drilling apparatusthat could be air-dropped and drilledinto a deeply buried, hardenedstructure in a time of one hour or less.The system had to operate unattendedand survive attempts to destroy it. Wewill accomplish survival by a combina-tion of speed and system burial. Weproduced a system design that allowedthe complete drilling apparatus to becontained in a large penetrator thatwould bury itself on impact and, inabout one hour, drill through 100meters of granite using a guided DTHHdriven by OTTO torpedo fuel. OTTOfuel is high-energy, anaerobic fuelwhose combustion products can beused directly to drive a DTHH, which isessentially a jack hammer driving astar drill. Penetration rates are inexcess of 1 meter per minute withexisting hammers, and analysispredicts up to 5 meters per minute,using the high energies that can beapplied using the OTTO fuel. The twoenabling technologies, DTHH drillingand OTTO fuel, are well-understood,mature technologies, but linking themwill require development work.

We organized a design review ofthe proposed system involving expertsin drilling, OTTO fuel, lethality agents,and penetrators. The review teamfound the concept to be feasible, withsome areas of difficulty. Most of thedifficult areas center on making thesystem survive 2000 G impact accel-erations. We showed that the conceptof a penetrator-contained drillingsystem is plausible with existingtechnology. In fact, the combination ofdirect use of the OTTO fuel for drivingthe hammer and DTHH drillingtechnology promises penetration rateshigh enough to reopen the possibilityof a surface-landed system. Expectedsurvival times would be much shorter,but penetration rates are projected tobe so high that an armored systemcould survive long enough to accom-plish its goal. The importance of theproblem presented by deeply buried,hardened targets, combined with theprobability that kinetic energypenetrators are near an end-point intheir development, leads to therecommendation that the drillingapproach be seriously pursued.Demonstration of the application ofOTTO fuel as a power source for aDTHH drilling apparatus would be aproductive first step, addressing theleast-developed aspect of the requiredtechnologies.

Publications

Other

Holcomb, D. J., and E. Ahrens. 1998.“Evaluation of a Microhole DrillingRobot for Penetration and Defeat ofDeeply Buried, Hardened Targets.”Sandia Technical Report SAND98-2651(October). Sandia National Laborato-ries, Albuquerque, NM.


3532.230

IFSAR Tree Phenomenologyand CoherenceNormalization

J. R. Fellerhoff

Recent developments in interfero-metric synthetic aperture radar (IFSAR)indicate a need to more completelyunderstand the phenomenology relatingto IFSAR digital terrain elevation data(DTED) measurements in vegetation.Several different research activities inthe literature showed a failure toproperly map tree heights with currentIFSAR terrain mapping algorithms, eventhough theoretical predictions indicatedthat these experiments should correctlycompute tree height in these digitalmaps. Sandia developed a detailedunderstanding of radar phenomenologyand is seeking to apply this knowledgeto the problem of IFSAR tree-heightmeasurement.

This analysis comes at a criticaltime for the U.S.’s future involvement inIFSAR development. We initiated anadvanced concept technology demon-stration (ACTD), called rapid terrainvisualization (RTV), to demonstrate thefeasibility of mapping large areas atextreme accuracy for battlefield plan-ning and precision navigation andguidance. This system will require moreaccuracy in the measurement of treeheight in terrain maps than can bedemonstrated with current algorithms. Asuccessful Sandia phenomenology studywill greatly benefit the future of U.S.IFSAR airborne and spaceborne terrainmapping systems by providing moreaccurate digital terrain elevation maps.

In addition to DTED maps,airborne and spaceborne IFSAR systemsproduce an extremely useful productcalled the coherence image. Thecoherence image contains informationabout both the performance of the radarsystem and the characteristic of mea-sured objects in the image. Target andscene recognition techniques could be

improved if radar system effects couldbe separated from vegetation phenom-enology. This project will address thevegetation phenomenology as theseparation of systematic radar coher-ence effects from the effects of scenecontent.

Success of this project willposition Sandia as a national leader inIFSAR terrain mapping, a necessaryproduct for future operational militarytraining, as well as for the precisionnavigation and guidance of weapons,both conventional and nuclear.

We collected SAR data with theTwin Otter SAR system and initiated adetailed analysis effort to look at treecoherence and the wave problem. Wemade substantial progress towardanalytical predictions and empiricalobservance of the phenomenon. Thereare over 30 potential error sourcesthat could contribute to the phenom-enon we are experiencing. Initialanalysis of the physics governing theeffects eliminated some, and analysisof the flight data allowed us to furtherfocus our research activities in thefuture.

We initiated additional analysisgoverning the effects of tree phenom-enology. The prevailing consensus isthat decorrelation due to volumetricscattering may not be the dominanterror source, as previously believed.Instead, it appears the decorrelation inthe layover regions and shadowregions may be causing the phaseunwrapper to improperly reconstructthe trees. We believe a previouslyproposed multibaseline technique thatwill eliminate the need for phaseunwrapping is the correct solution tothis problem.

Publications

Other

Burns, B. 1998. “Analysis of IFSARError Sources.” Internal memorandum,Sandia Technical Report, in prepara-tion. Sandia National Laboratories,Albuquerque, NM.

3532.240

Electric Launcher forDefense Applications

D. M. Rondeau, K. W. Reed, L. X.Schneider, B. E. Swanson, R. B. Asher,W. P. Schimmel, E. A. Weinbrecht, S. L.Shope, J. I. Crowther, Jr., B. M. Marder

We conducted a study assessingthe application of Sandia-developedcoil-gun technology for two airborneapplications in support of Sandia’sEmerging Threats Strategic BusinessUnit. An electric gun, of which a coil gunis one type, provides kinetic energy to aprojectile from stored electrical ormagnetic energy delivered in a fewmilliseconds. The primary elements arethe power source, an energy storagedevice, a power peaking device, and theconversion elements from electric tokinetic energy. Potential advantages ofthis technology over conventional,chemically fired munitions includesignificantly higher velocities andkinetic energy levels, elimination ofexplosive propellants along withcombustion gases and their issues,simplified loading and lower manninglevels, increased stand-off range,increased penetrator lethality, andmission flexibility.

Two types of electric guns are ofinterest for large aircraft and fighterapplications: a rail gun and a coil gun.In a rail gun, the conversion fromelectrical to kinetic energy is obtainedfrom the magnetic fields generated bycurrent flowing through sets of parallelrails, with the projectile armaturebeing pushed by the interaction of themagnetic field with the current flowingthrough the armature. Current flowthrough the moving armature isestablished and maintained throughcontact with the rail, and this gener-ates a plasma with substantial resistiveloss and rail wear. In a coil gun, kineticenergy is imparted to the projectilethrough a series of sequentiallyswitched magnetic coils. The coil gunhas no electrical contact since it


couples magnetically, and the forcesare such that the projectile tends to beself-centered within the barrel and ismagnetically levitated on the center-line. The coil gun consists of asequence of coils surrounding a flywaythrough which a conducting armaturepasses. A rapidly rising magnetic fieldassociated with energizing the coilsinduces a current in the armature,producing a force. We achievedvelocities in excess of 1 km/s with a2-inch-diameter, 240-gram aluminumprojectile in a 1.6-meter tube. Pastexperiments demonstrated coilstrength, operating reliability andcontrollability, and benchmarking ofsimulations. We achieved coil strengthand launch pressure of 1.1 kbar. Wepresume that an increase in coilstrength to 2.0 kbar by 2005 is veryfeasible, and a 3–4 kbar pressure rangeby 2015 is possible.

We are evaluating two generalapplications for electric-gun technol-ogy: a replacement for a 105 mmHowitzer aboard a large aircraftgunship, and an integral frame-mounted weapon for the future-generation Joint Strike Fighter. For thelarge aircraft application, we areanalyzing projectiles of 4 to 8 kg inmass, and muzzle velocities of 1.5 to2.0 km/s. For the fighter aircraft, weare assessing projectile masses of 0.4to 1.2 kg and muzzle velocities of 1.7 to2.5 km/s. Several integral technologyareas will require significant develop-ment and some research to realize thefull potential of a coil gun in theseapplications: high-strength coil design,energy supply and storage, and fire-control system.

Preliminary assessments indicatethat the system weight for the largeaircraft application is on the order of6,500 to 11,500 pounds by the year2015 for a 4 kg, 1.7 km/s projectile andan 8 kg, 1.7 km/s projectile, respec-tively, utilizing a compulsator/capaci-tor power conditioning system. Fighteraircraft systems weights rangedbetween 1,900 pounds in 2015 for a 0.4

kg, 1.7 m/s projectile, and 6,000pounds for a 1.0 kg, 2.5 km/s projectile.

We established a developmentprogram schedule and resourceestimate to provide for significantdesign and development efforts in coil-gun operations, power supply storage,switching, smart and maneuveringprojectiles, trainable gun with assistedtarget recognition, and aircraftintegration testing and demonstration.

Publications

Other

Rondeau, D. M. 1998. “Application ofCoilgun Technology for MilitaryAircraft.” Paper presented to theDirected Energy Technology Review,Dayton, OH, 29 September.

3533.180

Power-Grid Reliability andRestructuring PolicyChanges

D. G. Robinson, A. B. Baker

The objective of this project is toprovide additional insight into the effectof policy issues associated with restruc-turing of the power industry on theability of the industry to provideadequate and secure power to theconsumer. This project suggests that twointerrelated areas of investigation beundertaken: (1) availability of off-sitepower to nuclear power plants, and (2)power-grid reliability. Research under-taken in this project was limited tocharacterizing the impact of restructur-ing on the availability of quality powerto the consumer.

This research was the result of acooperative effort between Sandia,Associated Power Analysts, Inc. (APAI),and Texas A&M University to charac-terize the impact of a changingregulatory environment on thereliability of customer electricalservice. We desired to assess the

impact in as realistic an environmentas possible. Because of the availabilityof data, the initial study centered onthe electric power grid in Texas.Specifically, we used data from theElectric Reliability Council of Texas(ERCOT) for the 1997 operational yearin the research. Based on geographyand location of generation andtransmission lines, we considered tenbasic areas and modeled each area asa single-point generation and load.Sandia developed a number of restruc-turing scenarios that APAI investigatedusing their N-Area Reliability Program(NARP). The present study is limited toan assessment of the adequacyaspects of reliability: sufficiency ofinstalled generation and transmissioncapacity to satisfy the needs of allconsumers in a steady-state sense. Theresults are, on one hand, conservativein that they address only the impact ofpeak loading. Alternatively, they areoptimistic in that the transmissionlines are assumed to be in continuousoperation. The major results of thisstudy indicate that, in a new regula-tory era, the reliability of customerservice will be significantly impacted,possibly in a negative fashion, unlessthe effects of the ensuing economicpressures are understood and appro-priate actions are taken.

Publications

Refereed

Patton, A. D., C. Singh, and D.Robinson. 1998. “Impacts of Deregula-tion on the Reliability of a Multi-AreaPower Pool.” Proc. IEEE Power Sys.Computation Conf., accepted.

Other

Patton, A. D., C. Singh, and D.Robinson. 1998. “The Impact ofRestructuring Policy Changes onPower-Grid Reliability.” Sandia Techni-cal Report SAND98-2178 (October).Sandia National Laboratories, Albu-querque, NM.


3533.050

SAM Telemetry forMeasurements While Drilling

S. Ballard, G. T. Barker, T. W. Caffey, A.J. Mansure, R. G. Keefe, L. C. Bartel

The need for a reliable, fast,wireless telemetry system in the drillingindustry is great, but the technicalchallenge to develop such a system ishuge. Sandia tested a downhole wirelesstelemetry system based on surface areamodulation (SAM). SAM telemetrymodulates an electrical current flowingalong the drillstring. We monitor thecurrent modulation at the surface withan ammeter. We encode downhole dataand transmit them to the surface as apattern of current oscillations.

In a field test, the SAM systemsuccessfully transmitted downholeinformation from depths of 1,400 feetbelow the fluid level to the surface at arate of 110 baud. One of the configura-tions tested improved the data transmis-sion rate at a given depth by more thanan order of magnitude, and increasedthe maximum depth from whichsuccessful data telemetry could beachieved by more than a factor of two.

The need for a reliable, fast,wireless telemetry system in thedrilling industry is great, but thetechnical challenge to develop such asystem is huge. We field-tested theSAM system for measurement-while-drilling (MWD) well applications.During the test, we transmitted datasuccessfully at 300 baud from depthsof 550 feet below the fluid level using acoaxial configuration (configuration#1), and from depths of 1400 feetbelow the fluid level at a rate of 110baud using an align electrode configu-ration (configuration #2). Theseperformances were limited by thesignal power generated by SAM, by theattenuation of the signal as it traveledback to the surface, and by thehardware used to encode and decodethe data. For example, we recordedsignals from 900 feet below the fluidlevel with configuration #1, but couldnot decode them. The risetime of these

signals suggests that with propermodulation/demodulation, 110-bauddata may have been transmitted from900 feet below the fluid level withconfiguration #1.

Clearly the test did not achievethe dream of kilobaud data from 20,000feet. Pretest predictions were that forconfiguration #1 data transmissionwould drop to below 110 baud beforethe bottom of the ~ 2,000-foot test well,and it did. We also predicted thatconfiguration #2 would provideconsiderable benefit, and it did. Interms of actual measured perfor-mance, configuration #2 improved thedata transmission rate at a given depthby an order of magnitude and in-creased the depth to which telemetrywas successful by more than a factorof two.

Because the test well was only~ 2,000 feet deep, extrapolation isrequired to predict what telemetryrates might be achievable at depths atwhich MWD becomes economic. Weanalyzed the data using three differentapproaches that arrived at essentiallythe same conclusions, lending credibil-ity to their extrapolations. Extrapola-tion of the configuration #1 resultssuggests that data rates of 1 to 10 bitsper second should be possible at10,000-foot depth, the same ratesachievable by conventional electro-magnetic (EM) systems. It wouldappear that the difference betweenconventional EM systems and configu-ration #1 SAM is primarily a function ofthe signal power at the SAM package.

We found that configuration #2provides, at a fixed depth, 100 timesthe bandwidth or, at a fixed bandwidth,10 times the depth before signal dropsbelow noise. Compared to configura-tion #1, configuration #2 provides themaximum signal power at the SAMpackage. Whereas extrapolations ofconfiguration #1 to depth gave thesame bit rates as conventional EMsystems, we demonstrated configura-tion #2 to have significantly betterperformance.

Considerations beyond thescope of this test and analysis arechanges in performance due to

changes in geology, cultural noise, andinput power. The test well penetratedshaly sand formations with 10-ohm-meter resistivity, which, while not aworst-case geology, was not favorableto data transmission. Although the testwell was surrounded by producingwells, and some of the time theengines of the workover rig on the wellwere on, we measured no variations incultural noise, and thus no conclusionshould be made as to whether thetests were noise-favorable or -unfavor-able. In theory, we can increase thesignal by increasing the power supplyoutput, provided the power supplydoes not contribute to the noise;however, such considerations arebeyond the scope of this work.

The field test was not successfulin demonstrating configuration #1 SAMtelemetry as an improvement overcurrent MWD EM telemetry, but it diddemonstrate that configuration #2 hasthe potential to significantly improvethe rates of data transmission.

Publications

Other

Mansure, A. J., R. G. Keefe, T. W. H.Caffey, L. C. Bartel, and S. Ballard.1998. “The Surface Area ModulationDownhole Telemetry System forMeasurement While Drilling.” SandiaTechnical Report SAND98-0778 (April).Sandia National Laboratories, Albu-querque, NM.

3533.160

Advanced GeosphereTransport Simulation

M. J. Martinez, P. L. Hopkins, P. C.Reeves

Numerical simulation is a keytechnology in system design, regulatoryassessment, and decision analysis forradioactive-waste disposal and subsur-face environmental remediation. Presentlimitations in computational technologydrive model simplifications in the rangeof physical processes simulated, site


geometry, and geologic realism, withsignificant negative impacts: (1)simplifications become regulatory pointsof contention, (2) critical details aboutfast-path transport are lost, and (3)turnaround times for assessing uncer-tainty are too long to drive projectdecisions. A massively parallel (MP)geosphere transport model will over-come these limitations and place Sandiain an advanced position with respect torepository simulation capabilities.Sandia has a unique opportunity toleverage major Defense Program (DP)investments in computational simulationand to develop a fast, flexible geospheretransport simulation capability, runningon MP computers and networkedworkstations. We are building thisproject on a recently completed MPresearch code, which will be a keycomponent of the long-term strategicinitiative to significantly enhanceperformance assessment capability. Thiscode will also have the potential toenhance R&D in other technologieswhose performance hinges on under-standing and controlling geospheretransport.

(1) Code upgrades. (a) Toefficiently manage this multidevelopersoftware project, we placed the sourcecode under the CVS (concurrentversions system) software controlsystem. This enables simultaneoussoftware development among themany developers in the MPSalsa familyof codes and enables continuation ofour collaborations in a much morecost-effective way. We implementedseveral key code capability upgradesthat facilitate implementation of aliquid-phase advective/dispersivetransport capability. The moreimportant upgrades completed includeenabled linking with updated NEMESISparallel input/output (I/O) library andthe updated AZTEC parallel solverlibraries for improved performance;implemented user-driven specificationof relative permeability and capillarypressure models, with automaticJacobian calculation; and extendedand improved the equation-of-state(EOS) models for phase appearance/disappearance. By leveraging on-going

work, these upgrades also enablecoupled physics modeling and meshadaptation developments. (b) Weimplemented a control-volume–basedstabilization method for convection-dominated flows and for dealing withphase transitions and verified it onseveral test problems, including 1-Dheat-pipe and 2-D and 3-D JornadaTrench problems. The method iscontrol-volume conservative, butallows general unstructured gridding.We developed and implemented aspecial quadrature rule. This feature isessential for stable numerical treat-ment of phase appearance anddisappearance in the flow equations.

(2) Geostatistical simulationcapability. The aim of this task is tofacilitate flow and transport simula-tions over a fully heterogeneous fieldin which multiple formation andhydrologic properties have beengenerated by geostatistical simulation(GSLIB) software. The GSLIB softwareis the current industry standard andallows for the estimation and simula-tion of spatially correlated propertiesin two and three dimensions. Bothmaximum entropy (multigaussian) andindicator–based spatial fields can becreated as input to the simulator. Wedeveloped a preprocessor both as ameans of generating heterogeneousproperty fields and as an interfacebetween the transport simulator andthe GSLIB software. The currentversion of the preprocessor includesembedded logic for generatingspatially uncorrelated materialproperties according to uniform,random, normal, and lognormaldistributions. Properties generatedwith more sophistication by GSLIBsoftware can be written to an ASCII(American Standard Code for Informa-tion Interchange) file and used as inputto the preprocessor. These propertiesare typically generated on a well-defined, structured grid. We developeda nearest-neighbor method for map-ping the heterogeneous propertiesfrom the geostatistical simulation gridonto the finite-element (FE) grid(structured or unstructured) used inthe transport simulator.

(3) Verifications. For purposes ofverification, we tested the code on aset of standard problems designed toexercise different aspects of the code.In addition, we applied the code to aseries of sample problems modeledafter the proposed Gas Migration Testbeing conducted by the JapaneseRadioactive Waste Management Centerat the Grimsel site in Switzerland. Thistest will assess the gas migrationbehavior of a 1/10th-scale repositorycontainment placed in a crystallinerock that contains a steeply dippedfracture zone. These efforts demon-strated our abilities to modelmultiphase flow in complex 3-Dgeologic systems (200,000 grid points,400,000 unknowns) running over alocal-area network (LAN).

Publications

Refereed

Martinez, M. J., and P. L. Hopkins. 1998.“A Two-Phase Thermal Model forSubsurface Transport on MassivelyParallel Computers.” Proc. 10th Internat.Conf. on Finite Elements in Fluids 1(Tucson, AZ, 5–8 January): 468–473.

Martinez, M. J., P. L. Hopkins, and J. N.Shadid. 1997. “MultiphaseNonisothermal Subsurface Transporton Parallel Computers.” Proc. 1997ASME Internat. Mechanical Engin.Congress and Expo. 224 (Dallas, TX, 16–21 November): 413–422.

Other

Martinez, M. J., P. L. Hopkins, and P. C.Reeves. 1998. “Progress Report onAdvanced Geosphere TransportSimulation LDRD.” Sandia internalmemorandum to Distribution (10 July).Sandia National Laboratories, Albu-querque, NM.

Martinez, M. J., P. L. Hopkins, S. A.Altman, and P. B. Davies. 1997.“Numerical Simulation of Noniso-thermal Flow on Massively ParallelComputer Architectures.” Brochure/Poster for ASCI–Sandia Booth at SuperComputing ’97 Conference, San Jose,CA, 15–21 November.


3533.070

Design-for-ManufacturabilityApplied to PhotovoltaicModules

J. M. Gee, S. E. Garrett, W. P. Morgan

The purpose of this project is toapply modern manufacturing designprocedures (e.g., design for manufac-turability) and manufacturing processesfrom other mature industries (e.g.,printed circuit boards and flexiblecircuits) to photovoltaic (PV) modulemanufacturing. The goal of the project isto reduce module assembly cost by afactor of two, which corresponds to a25% decrease in the manufacturing costof the PV module. The new concept(Monolithic Module Assembly) encapsu-lates and electrically connects all thecells in the module in a single step,which can be achieved only withsignificant changes in the PV cell andmodule design. Sandia will develop anassembly process that (1) uses back-contact cells, (2) uses a modulebackplane that has both the electricalcircuit and encapsulation material in asingle piece, and (3) uses a single-stepprocess for assembly of these compo-nents into a module. This processreduces cost by reducing the number ofsteps, by eliminating the low-throughput(e.g., individual cell tabbing) steps, andby using completely planar processesthat are easy to automate. Back-contactcells are crucial for this project becausethe coplanar geometry allows attach-ment of leads to both polarities in thesame step. This work will use a Sandia-proprietary solar-cell concept (emitterwrap-through cell) that has both contactson the back surface. A variety ofmaterials and conductor applicationmethods from the printed circuit boardindustry can be used for the modulebackplane. Similarly, the printed circuitboard industry routinely bonds a largenumber of devices to a board in a singlestep using a variety of methods (e.g.,solder and conductive epoxies). If

successful, this work will lead topatentable advances in technology, willhelp position PV technology for substan-tial capacity additions at lower cost, andwill be applicable to future PV technolo-gies (thin-film and concentrator).

The goal of this final year of theproject was to develop a prototypeusing more cost-effective materials.During the first year of the project, wedeveloped a prototype that demon-strated the concept—electrical andmechanical assembly of a PV modulein a single step. This first-year proto-type used a fairly expensive material(conductive epoxy) that also did notperform very well in thermal cyclingtests. Hence, we examined low-temperature solders. Solder is lessexpensive, has lower electricalresistance, and is likely to be morereliable than conductive epoxy. Weexamined relatively low-temperature,bismuth–based solders to be compat-ible with standard encapsulationmaterials (ethylene vinyl acetate) andprocess time-temperature-pressurecycles. We were concerned about theability of the solder to wet the solarcell and interconnect during thelamination cycle. The problem is thatthe encapsulation material melts andflows during the lamination cycle andmight prevent formation of the solderbond. We were successful in laminatingmodules with low-temperature solders.Cross-sectional analysis of the bondssuggested that the bonds were notvery continuous, and initial thermalcycling testing also indicated problemswith the bonds. We believe that wecould improve the continuity of thesolder bonds with some simplechanges in the process (geometry ofthe solder bond and stabilization ofthe interconnect). We assembled PVmodules using the new process withlow-temperature solder bonds andachieved a solar-to-electric conversionefficiency of 13%. This is a substantialimprovement over the 11% efficiencyachieved in the first year of theproject.

Publications

Refereed

Gee, J. M., D. D. Smith, S. E. Garrett, M.D. Bode, and J. C. Jimeno. 1998. “Back-Contact Crystalline-Silicon Solar Cellsand Modules.” Proc. NCPV ProgramReview Mtg. (Denver, CO, September).

3533.170

Low-Work-FunctionThermionic EmissionMaterials

D. B. King, J. A. Ruffner, K. R. Zavadil

Thermionic converters or diodesare two electrode devices that convertheat energy to electrical power. Theelectrodes are spaced opposite eachother. A heat source elevates thetemperature of the emitter electrode.Electrons are then thermally evaporatedinto the interelectrode space betweenthe emitter and collector electrode. Thehigh working temperatures represent anoperational limitation. A process tofabricate low-work-function electrodematerials will allow the diode to operateat substantially lower temperatures.Promising materials for use as a cathodeare scandia-stabilized, alkaline earthoxides. Scandia appears to provide twocritical functions in a cathode, depend-ing on how the cathode is fabricated. Formixed matrix-oxide cathodes, scandiaappears to stabilize an emitter likebarium (Ba), prolonging its surfaceresidence time and reducing its loss ratefrom the near-surface region and fromthe bulk of the oxide. Sandia willdevelop methods of thin-film depositionamenable to incorporation into micro-electronic fabrication schemes. Themixed matrix oxide is the more attrac-tive alternative for microelectronicapplications predominantly because ofreported lower operating temperaturesand an anticipated greater stability ofBa. The mixed oxide should allow amove away from the traditional, bulky


dispenser structure with a large capacityto a thin-film technology. In addition, wewill investigate alternate evaporationand chemical vapor deposition (CVD)routes for cathode formation. We willdeposit mixed Ba and scandium (Sc)oxide films by co-evaporating the metalsfollowed by thermal oxidation. Metallicdeposition affords an opportunity togradate the Ba concentration in the filmand preserve an excess concentration ofzero-valent Ba at the film/substrateinterface. This excess represents theadditional capacity required with slowloss of Ba from the surface of the film.

The aim of this project is todevelop a low-work-function thermionicemission material with appreciableelectron emission at modest operatingtemperatures. The material must also becompatible with all microelectronicfabrication processes that will be used tocreate the new converters.

We successfully developed amethod for fabricating scandate–basedthermionic emitters in thin-film form.Our approach was to incorporateBaSrO (BSCO) into a Sc2O3 matrix usingRF sputtering to produce thin films.Testing shows the resulting films to beelectron emissive at temperatures aslow as 900°K with current densities of0.1 mA¾cm-2 at 1100°K and saturationvoltages. We estimate an approximatemaximum work function of 1.7 eV. Filmcompositional and structural analysisshows that a significant subsurfacealkaline earth hydroxide phase canform and probably explains the limitedutilization and stability of Ba and itssurface complexes.

We deposited a variety of thinbilayer films onto a tantalum (Ta)electrode on silicon (Si). The filmshave four discrete layers sitting on topof the Si substrate: (1) 400 nm ofthermally grown SiO2, (2) 500 nm ofsputter-deposited Ta, (3) < 400 nm of

BSCO, and (4) 400 nm of Sc2O3. TheBSCO layer forms platelet crystalsoriented parallel to the surface, andSc2O3 forms columnar crystalsoriented perpendicular to the sub-strate. The films have a specularsurface finish when first removed fromvacuum, but rapidly develop surfacetexture with exposure to atmosphere.We found that thicker scandia cappinglayers, elevated temperature deposi-tion (300°C), and introduction of O2

into the RF plasma all slow the devel-opment of this surface texture. Mass-gain measurements made as a functionof post-deposition atmosphericexposure are consistent with theuptake of H2O to form a hydroxidephase. We believe that the columnarscandia crystal structure is largelyresponsible for the high permeabilityto H2O and subsequent hydroxideformation.

We used surface spectroscopy toverify the existence of the hydroxide.X-ray photoelectron spectroscopyshows that Ba and strontium (Sr) arealways present on the surface of thesefilms. The relative hydroxide-to-oxidesurface concentration scales with theamount of surface Ba and Sr. Thisfinding argues that these species aretransported through the scandiaoverlayer due to the activity of H2O.We achieved the lowest degree of Baand Sr conversion and transport withdeposition at temperature, in oxygen,and with thicker capping layers. Cross-section scanning electron microscopy(SEM) analysis shows that the hydrox-ide presence is localized. Using energydispersive x-ray fluorescence, we areable to collect compositional informa-tion from each of the discrete layersand the hydroxide layer. We find thatthe scandia capping layer is still intactbelow and to either side of the hydrox-ide. We also find that the relative 0°K

level emission is significantly greaterin the surface feature than either theunderlying Sc2O3 or BSCO. Thisobservation is evidence of localizedhydroxide formation in the surfacefeature. We concluded that H2O ingressoccurs locally, first permeating andforming an underlayer hydroxide, thenhydrating to an extent where transportof Ba2+ and Sr2+ through the scandia ispossible. Hydroxide phase formationthen continues locally at the surface.The hydroxide is an undesirable phasebecause electron emission would notbe occurring exclusively from a Ba-Sc2O3 surface complex. We do find thatthe sample is electron emissive.Emission data show expected diodecharacteristics with a nearly zerocurrent region corresponding to thework-function difference of the emitterand collector, a linear region ofretarded mode operation, a decreasein current rise with diode voltageindicative of space charge, and, finally,a slow rise in current with voltageevidence of saturation. We estimatethat the emitter work function is lessthan 1.7 eV. We find that the currentoutput of these emitters is not stablewith time, resulting in eventualdecrease. This instability is a result offirst depleting Ba from the hydroxidephase, explaining the high initialcurrents, followed by Ba diffusion fromthe BSCO underlayer, and electronemission from discrete local regions ofthe surface.

Publications

Refereed

King, D. B., J. R. Luke, and F. J. Wyant.1998. “Results from the MicrominiatureThermionic Converter DemonstrationTesting Program.” AIP Conf. Proc. 13th

Symp. on Space Nucl. Power andPropulsion, accepted.


3534.030

LIGA Micromachining

J. M. Hruby, B. V. Hess, A. M. Morales, R.H. Nilson, S. K. Griffiths, M. X. Tan, D. R.Boehme, W. D. Bonivert

The LIGA (German for lithography,electroforming, molding) process usessynchrotron radiation to create patternsof fine-featured structures inpolymethylmethacrylate (PMMA). Thesepatterns, once developed, become ahigh-aspect-ratio mold that can be filledwith other materials chosen for theintended application. Most commonly,metal is electrodeposited into the PMMAmold to produce metal or metal alloymicromachines. The micromachinesproduced through the LIGA processtypically have aspect ratios greater than10:1, can be made from a variety ofmetal or plastic materials, and are wellsuited to actuation as well as sensingfunctions. LIGA bridges a gap in minia-turization between silicon (Si)micromachining (a few microns) andprecision machining (a few millime-ters). At Sandia, LIGA micromachiningcomplements our expertise in Si surfacemicromachining and compoundsemiconductor patterning.

In this project, we establishedcapabilities to conduct all the LIGAprocess steps at Sandia except thesynchrotron exposure and negotiateddedicated beam lines. The infrastructuredeveloped includes the design andprocurement of a flexible LIGA scannerfor synchrotron exposures, LIGA maskmaking, chemical development of high-aspect-ratio patterns in resist, a betterunderstanding of electroplating of high-

aspect ratios, nonsynchrotron high-aspect-ratio mold making, and Web–based software for process predictions.Through this project Sandia has estab-lished a world-class LIGA capability thatwill be used by many customers.

During FY98 we accomplishedthe following:

(1) Completed the design of aLIGA scanner for synchrotron expo-sure. This scanner allows masks largerthan 3 inches, multiple masks to bemounted at one time, mask rotation for3-D exposures, and a user-friendlycontrol architecture. We procured thisscanner and began initial testing.

(2) Established and optimizedthe processing of Si substrate mask-making capability. This work wasaccomplished in collaboration with theUniversity of California–Berkeley cleanrooms. In parallel, we establishedclean-room capabilities onsite andprocured an ultraviolet (UV) aligner.We also successfully explored alterna-tive substrate mask-making capability.

(3) Procured and installed a newplating line that was specially designedfor plating LIGA hardware. This platingline includes the capability to preciselycontrol the current, to continuouslymonitor the plating conditions, and tohave as many as eight chemistriesavailable for plating LIGA parts. Inaddition, we studied and documentedmodeling to improve our understand-ing of the effects of natural convectionon electroplating. This work led toboth new understanding and sug-gested methodologies to improveelectroplating uniformity. We initiatedtesting on the new, improved method-ology.

(4) Implemented a LIGA softwarearchitecture that included Web-sitedesign and installation, image librarywith remote upload and downloadcapability, and remote Web-browserversion of LEX (LIGA exposure) codes.

(5) Explored options fornonsynchrotron-exposure high-aspect-ratio structures. This work led toalternatives for structures that are 50to 100 microns in depth.

Publications

Refereed

Griffiths, S. K., R. H. Nilson, R. W.Bradshaw, A. Ting, W. D. Bonivert, J. T.Hachman, and J. M. Hruby. 1998.“Transport Limitations in Electrodepo-sition for LIGA Microdevice Fabrica-tion.” Proc. SPIE, Micromachining andMicrofabrication Process Technol. IV3511 (Santa Clara, CA, 21–22 Septem-ber): 364–375.

3534.040

Applied MicrofluidicsScience

E. B. Cummings, T. L. Prast, A. J. Salmi,S. K. Griffiths, R. H. Nilson, P. H. Paul

We developed a microparticle-image-velocimetry system and analysissoftware for measuring fluid velocityfields, electric fields, and viscosity fieldsin microchannels. We developed ameans of rapidly and inexpensivelymicrofabricating microfluidic systemsusing SU-8, a photopatternable clearepoxy. Our theoretical and numericalinvestigations into electrokineticallypumped microfluidics reveal that, in a


wide class of geometries, these flows areirrotational and subject to simplenumerical and even analytical treat-ment. We also derived analyticalexpressions for hydrodynamic disper-sion in capillaries with applications tooptimizing the design of electrophoreticand capillary electrochromatographiccolumns. In collaboration with col-leagues from the University of Floridaand Washington State University, westudied boiling in microchannelsnumerically and experimentally.

(1) Developed experimentaltechniques. To supplement our caged-dye fluorescence imaging tool, wedeveloped an epifluorescence multiple-camera video microscopy system forperforming particle-image velocimetry(PIV) and ratiometric fluorescenceimaging measurements in opticallyaccessible microchannels. The PIVsystem uses dyed latex nanospheres(20–200 nm-diameter) that fluorescestrongly enough that individuals canbe tracked. Behaving like macromol-ecules in solution, these particlespermit measurement of electro-phoretic, convective, and Brownianmotion fields via PIV. Because many ofthe flows of interest are electricallydriven, a component of the particlemotion arises from electrophoresis.The contributions of convection andelectrophoresis to the motion of theparticles are independently inferred bysimultaneously observing with twocameras the motion of particles withdifferent electrophoretic mobilitiesand fluorescence wavelengths.

To analyze the particle-imagedata, we utilized µPIV, an in-houseinteractive and automated graphicaluser interface (GUI)–based image-

processing code written in C++ for thisprogram. This code utilizes fastFourier transforms to perform imagecross-correlation. An arbitrary numberof sequential images can be incorpo-rated into the same analysis, allowingaveraging of the correlation functionsfor stationary flows. The innovativefeatures of the code are automatic gridrefinement, averaging of the correla-tion, and an ability to measure gradi-ents and curvature in the velocityprofile in the unresolved direction(normal to the imaging plane).

(2) Developed fabricationmethods. We developed a capacity todesign and microfabricate microfluidictest structures in house. Microelec-tronics at Sandia provides a photoplotof our computer-aided design (CAD)with ~ 30 µm resolution that we use asa mask for patterning SU-8, a photo-definable epoxy. We fabricatedchannels with SU-8 walls, floors, andceilings by (a) spinning SU-8 (~ 1 µm)onto the surface of a wafer, photo-patterning the desired channel floor,dissolving the undesired sections, andcuring at ~ 130°C; (b) spinning the walllayer (typically 50 µm thick) of SU-8onto this coated wafer or slide,photopatterning the channels, dissolv-ing the channels, and curing at~ 130°C; and (c) spinning SU-8 onto amicroscope cover slip for the channelceiling, baking out excess solvent,assembling the top and bottom pieces,placing in a vacuum bag, and baking at~ 130°C, producing a sealed, all-epoxychannel. The SU-8 is chemically inertand nonfluorescent and features high-aspect-ratio walls (50:1). The develop-ment of this rapid and inexpensivefabrication technique is ongoing.

(3) Developed theory ofmicrofluidics. We made strides inunderstanding the nature of electroki-netic (EK) flows when the electricaldouble layer is much smaller thanboundary dimensions, as is typical formicrofabricated devices. We showedtheoretically and numerically thatpurely EK flow away from conductingsurfaces and surface and fluid inhomo-geneities is irrotational except in theelectrical double layer. Thus bulkelectrokinetically pumped flows arepotential flows, a much-studied andtractable class of flows that are exactsolutions to the Navier-Stokes equa-tions for all Reynolds numbers. Wealso explored how inhomogeneitiesand conducting walls can producevorticity and pressure fields.

We also derived analyticalexpressions for hydrodynamic disper-sion in an open cylindrical channel.These solutions will assist designerswith understanding the optimumscaling for electrophoresis columnsand capillary electrochromatographiccolumns.

(4) Investigated boiling inmicrochannels. In our ongoing univer-sity collaboration, we began to explorephenomena related to boiling inmicrochannels. We experimentallyexplored the boiling of water, FC-72,and pentane in capillaries andmicrochannels using standard resis-tance heaters and a novel 100-elementfeedback-controlled microheater arrayprovided by one colleague. Anothercolleague helped with physicallymodeling the liquid-vapor meniscus inboiling. Boiling and bubble formationare either useful or problematic for awide range of microdevices.


3535.130

Computational Simulationsof Self-Assembling Macro-Systems by DirectFabrication of MicroscopicStructured Materials

S. Istrail, J. Cesarano, III, V. Tikare

Sandia is modeling and testing theprocesses that direct self-assembly ofmacroscopic components in an effort tounderstand and establish control overspontaneous structure formation ofsmall Janus bricks. (The simplest Janusparticle has one side hydrophobic, theother hydrophilic.) Janus bricks can beprogrammed with varying affinities foreach other on their faces and edges sothat red surfaces (e.g., hydrophobic)stick to red but not to blue (e.g., hydro-philic). With unlimited colors, anymacroshape could be self-assembled ifthe bricks had sufficient mobility andtime to find their proper neighbors bylow-temperature direct fabrication in aparallel self-assembling mode. Disparatematerials could be accommodated inneighboring bricks, and near-net-shapestructures could be formed out of fullydense bricks with minimal shrinkingfrom sintering. It is an open questionwhat shapes are possible with just twocolors and only one or two brick shapes.Moreover, since it is not clear whatprocess is required to sinter a Janusassembly, we are developing a phase-field sintering model to predict the end-state structures. We are using small,experimental systems to discover thephenomenology of simple Janus tiles,which have the attractive possibility ofself-assembling very simple virus-likecapsules from only six triangular tiles.

We explored isomorphismbetween Janus and Potts models. As aspecific case of hydrophobic-hydro-philic interactions, we found theboundary of computational tractability

for obtaining analytic, closed-formpartitions functions for the Isingmodel, specifically for the Ising Spin-Glass problem. In the process, wemade progress solving long-standingconjectures due to Onsager, Fisher,and Feynman related to the 3-D Isingproblem, the 2-D versus planarityproblem, and the second-neighborinteraction models. Using a phase-fieldformalism, we began to study thespecial problems that arise in sinteringan assembly of ceramic Janus bricks.

As a simple realization of Janusobjects, we worked experimentallywith glass microballoons. We coatedthese 100-micron-diameter bubbleswith a hydrophobic agent, thencrushed them into approximately flatplates having one side hydrophobic,the other (interior side) hydrophilic.We examined the interactions betweenuncrushed microballoons with bothtreated and pristine surfaces in waterby optical microscopy, then studiedthe behavior of shards in and on water.By far the strongest driving forceswere found when we captured par-ticles at a water-air interface: We foundJanus plates to be oriented hydropho-bic-side up regardless of initialdeposition method. Somehow theplates spontaneously flipped over,even though their width greatlyexceeds their thickness (exceeding100:1). On a water surface, these Janusplates attracted very strongly, appar-ently via long-range capillary interac-tions. Untreated plates had little or nointeraction. We have begun experi-ments to make LIGA-defined ceramicbricks.

Publications

Refereed

Hurd, A., and S. Istrail. 1997. “Predic-tion Algorithms for Nanobrick Self-Assembly.” Presentation to theAmerican Mathematics Society,Albuquerque, NM, 8 November.

3535.140

Self-Stabilizing OpticalSolitons and High-IntensityLaser Plasma Channels forDiffraction-Free Propagationand Robust PowerCompression

S. M. Cameron, D. E. Bliss

Optical channeling or refractiveguiding processes involving the non-linear interaction of intense femto-second optical pulses with matter in theself-focusing regime have createdexciting opportunities for next-genera-tion laser plasma–based x-ray sourcesand atmospheric remote-sensingapplications. This fundamentally newform of extended paraxial electromag-netic (EM) propagation in nonlineardispersive media such as clear air orunderdense plasma is attributed to theinterplay between normal opticaldiffraction and intensity-dependentnonlinear focusing and refractioncontributions in the dielectric response.Superposition of these mechanisms onthe intrinsic index profile acts to definethe propagating energy in a dynamicself-guiding longitudinal waveguidestructure, which is stable for powertransmission and robust compression.The laser-driven channels are hypoth-esized to support a degree of solitonictransport behavior, simultaneouslystable in the space and time domains(group velocity dispersion balances self-phase modulation), and are believed tobe self-compensating for diffraction anddispersion over many Rayleigh lengthsin contrast to the defining characteristicsof conventional diffractive imaging andbeamforming. By combining concen-trated power deposition with well-ordered spatial localization, thisphenomenon will also create newpossibilities for production and regula-tion of physical interactions, includingelectron beams, enhanced material


coupling, and modulated wakefields,over extended gain distances withunprecedented energy densities.Harmonious combination of short-pulsex-ray production with plasma channelingresulting from a relativistic charge-displacement nonlinearity mechanism inthe terawatt regime has been shown togenerate high-field conditions conduciveto efficient multikilovolt x-ray amplifica-tion and peak spectral brightness. Werecently utilized white-light conicalemission generated by Kerr-inducedatmospheric filamentation to collectremote backscatter spectrum fromaltitudes exceeding 10 kilometers.Channeled optical propagation withintense short-pulse lasers will impactseveral critical mission areas at Sandia,including x-ray backlighting of pinchimplosions, nondestructive radiographicimaging of aging weapons components,high-power ultra–wide-bandwidth(UWB) single-cycle EM pulse generation,remote sensing, and lasermicromachining.

In collaboration with researchersat the University of Illinois–Chicago,we used a self-focused femtosecondultraviolet (UV) terawatt-class laserwith a focused irradiance of 1018 W/cm2 to produce L-shell x-ray emissionfrom gold targets. We acquired spectrausing an imaging crystal spectrometerof von Hamos type in mica (7th order)with an aluminized polycarbonate/kapton titanium filter set. The single-shot integrated x-ray yield near 10–14keV exceeded our predicted value of 1mJ/2p sr, and the observed spectrum,although occurring generally in theexpected spectral region for the neon(Ne)-like gold (Au) transitions, exhib-ited a predominant asymmetricalbroadband feature (~ 700 eV) superim-posed on Bremsstrahlung continuumand line emission (La,b,g). Such acharacteristic nonthermal emissionsignature arises from core-excitedionic state configurations (3d-2p, n > 3)and is direct evidence of a dynamicalhollow atom excitation mechanism in

which the energetic laser field collec-tively drives correlated multi-electronmotion to produce anomalously strongcoupling in the propagation channel.To our knowledge, this is the firstreported measurement of gold L-shellemission from a laser-producedplasma and is the direct result of theunique interaction conditions that canbe produced with high-intensity, short-pulse lasers. The achievable spectralradiances scaled to an existing hybridNd:glass laser deployed on the Zaccelerator using our experimentallymeasured conversion efficiency (~ 1%)above 10 keV would facilitate anefficient, ultrabright, hard x-raybacklighting source capable of opacitypenetration of pinch/capsule implo-sions with compressed area densities(rr ~ l–10). Corroborative measure-ments of the self-trapping channelingmorphology with spatially resolvedThomson scattering and x-ray pinholeimagery indicated the presence of alongitudinally extended multifocifilament structure exceeding 50Rayleigh lengths with < 5 mm radialextent characteristic of the relativisticself-focusing/charge-displacementmechanism. We also observed strongEM transients and coherent far-infrared (IR) emission at terahertzfrequencies as the result of space-charge fields generated at the focus ofthe optical pulse due to the largepondermotive force. We recordedpreliminary evidence of hot electronfilaments or streamers generated by awakefield or current pulse mechanismassociated with the channelingprocess in xenon. As part of theexperimental campaign, we also usedthe short picosecond x-ray bursts(recombination time < 5 ps) created byM-shell xenon (~ 1 keV) and L-shellbarium fluoride (~ 4–5 keV) to directlymeasure the impulse response of x-raydetector (XRD) and photoconductivedevice (PCD) devices. The measuredrisetime for both devices, deconvolvedfor instrument response, was found to

be approximately 100 ps, which mayhave important implications fordiagnostic analysis of mix andRayleigh-Taylor contributions in recenthydrodynamic evolution studies.

In parallel with experiments,modeling efforts have been ongoingtoward spectroscopic analysis anddeveloping predictive capability andstability criteria for the channelingmechanism. The theoretical analysisseeks to define stable eigenmodes inthe nonlinear Schrödinger equationgoverning the guiding process andelectrostatic force balance in thechannel. By correlating the modelresults with our experimental data,such as x-ray spectra and spatiallyresolved images, we established first-order optimization parameters andstability maps for efficient x-rayconversion. The basic computationalprocedure developed in this work willfind general usefulness in a variety ofcases involving propagation in satu-rable nonlinear media different fromplasma, including Kerr self-focusing inatmosphere. High-intensity, short-pulse experiments in this regime inconjunction with adaptive pulseshaping are being pursued underanother project for remote-sensing anddirected-energy applications.

Publications

Refereed

Borisov, A. B., J. W. Longworth, K.Boyer, and C. K. Rhodes. 1998. “StableRelativistic/Charge-DisplacementChannels in Ultrahigh-Power-DensityPlasmas.” Proc. Nat. Academy ofSciences 95 (June).

Cameron, S. M., D. E. Bliss, and C. K.Rhodes. 1998. “Self-Guided LaserOptical Channeling in Air with High-Intensity Ultrashort Pulses: Applica-tions to Remote Sensing.” Paperpresented to the International Work-shop on Ultrafast Intense Laser PulsePropagation and Its Applications,Quebec City, Quebec, Canada, 19–20June.


3535.160

Optical CommunicationSystem for RemoteMonitoring and AdaptiveControl of DistributedGround Sensors ExhibitingCollective Intelligence

J. S. Wagner, K. M. Stantz, G. M.Loubriel, S. M. Cameron, M. W. Trahan

Comprehensive management ofthe battlespace has created newrequirements in information manage-ment, communication, andinteroperability as they affect surveil-lance and situational awareness. Theobjective of this project is to expandintelligent controls theory to produce auniquely powerful implementation ofdistributed ground–based measurementincorporating both local collectivebehavior and interoperative globaloptimization for sensor fusion andmission oversight. By using a layeredhierarchical control architecture toorchestrate adaptive reconfiguration ofsemiautonomous robotic agents, Sandiacan improve overall robustness andfunctionality in dynamic tacticalenvironments without informationbottlenecking. In this concept, eachsensor is equipped with a miniaturizedoptical reflectance modulator that isinteractively monitored as a remotetransponder using a covert lasercommunication protocol from a remotemothership or operative. We canleverage robot data-sharing at theground level with global evaluationcriteria, including terrain overlays andremote imaging data. Informationsharing and distributed intelligence openup a new class of remote-sensingapplications in which small, single-

function autonomous observers at thelocal level can collectively optimize andmeasure large-scale, ground-levelsignals. As the need for coverage andthe number of agents grow to improvespatial resolution, cooperative behaviororchestrated by a global situationalawareness umbrella will be an essentialingredient to offset increasing bandwidthrequirements within the net. A system ofthe type used in this project will becapable of sensitively detecting,tracking, and mapping spatial distribu-tions of measurement signatures that arenonstationary or obscured by clutter andinterfering obstacles by virtue ofadaptive reconfiguration. This methodol-ogy could be used, for example, to fieldan adaptive ground-penetrating radar(GPR) for detection of undergroundstructures in urban environments and todetect chemical species concentrationsin migrating plumes.

Highlighted achievementsconcerning the theoretical compo-nents are the development of twophysics–based collective behaviorsimulation codes, the development ofa parallelized genetic algorithm (GA)for optimization of behavioral charac-teristics, and new results focused onlocal/global coordination of collectivebehavior and adaptive reconfigurationof swarms looking at plumes andunderground structures. Two newphysics–based collective models, alattice gas (LG) and a particle-in-cell(PIC) (plasma–based) code, modelcollective behavior in a validatedframework that enables theoreticalcomparisons with statistical mechani-cal behavioral theory, taking advan-tage of well-benchmarked physicsmodels as an overall design tool. Eachrobot’s potential fields modeled by theLG or PIC simulations provide fast trip-

wire responses to an immediate targetor event, point-sensor information/transformation for further processing(targets vector direction), applicationof pseudo-potential fields (linked togenetically trained [recurrent] neuralnetwork decisions) to adapt to localdisturbances, and global imaging-likecapabilities to study and respond tothe environment. We developed andimplemented a parallel GA on top ofthese collective behavior models tooptimize spatial- and time-dependentnearest-neighbor potential interactionsthat realize adaptability in the swarm’sperformance (obstacle avoidance,GPR, remediation). We also studiedbehavioral performance versus otherphysical parameters, such as frictionand drag during flight dynamics, todetermine swarm behavioral changesfor the ballistic missile (PIC) andfighter-planes in dog-fight scenarios.

Laser optical communicationpotentially offers significant advan-tages for remote coordination and dataexfiltration from covert distributedground-sensing networks. The spatialcoherence of laser transmitters offersfavorable gain scaling with lowprobability of intercept, and therelative temporal coherence of theoptical carrier can support tremen-dous information bandwidth withoutbaseband interference or frequencyallocation problems. A major weaknesslimiting the operational utility ofnonideal optical communicationchannels propagating in atmosphere,however, has been adverse effects ofextinction (loss), scattering (disper-sion), turbulence (degraded coher-ency), and fade, which degraderealizable transmission bandwidth andgain aperture for acceptable bit errorrate. We investigated the use of a


previously developed active reflec-tance imaging technique based on anoptical parametric amplifier (OPA)receiver to enhance detector sensitiv-ity and error rate performance forunguided digital communication linksaffected by cloudlike conditions. Usinga kilohertz repetition-rate femtosecondlaser system operating at eyesafewavelengths, we evaluated the role ofsignal-spontaneous OPA beat noiseamplified spontaneous emission (s-ASE) on amplified signal, noise figure,and channel sampling capacity forvarious binary modulation formats inboth direct and coherent detectionmodes to establish fundamentalresponse limitations as a function ofturbidity.

As an example of the new type ofcooperative remote sensing andsynchronization that can be addressedwith a distributed collective operatingsynergistically at local and expertlevels, we completed a field test in astationary sandbox configuration thatemulates an adaptive ground-penetrat-ing impulse radar that is capable ofdetecting underground structures incluttered or propagationally dispersivebackgrounds. In these experiments, weused a fiber-coupled avalanche diodeto trigger multiple ultra–wide-band-width (UWB) RF transceivers (Yagi) atvarious time/phase delays (simulatinga distributed aperture of dipolepulsers optically triggered by photo-conductive switches) to study electro-magnetic (EM) superposition andtarget detection as a function of range(depth) and aspect (obliqueness). Weused UWB waveforms because ofpotential advantages associated withsignal interaction and extraction andimproved imaging discrimination. Byproperly assembling the array in

phase, amplitude, and spatial orienta-tion, a directive illumination patternwith adjustable transfer function canbe created to match the local measure-ment environment, including terrainobstacles and soil-layer attenuation.We compared experimental iterativesolutions qualitatively with the resultsobtained from intelligent (genetic)optimization algorithms for designvariables of the radiating structure,including element spacing, sensordensity, and sidelobe characteristics inrelation to detection criteria. Weexamined the general synthesisproblem of a sparse array of active EMelements subject to a fitness functionthat optimizes a matched filter for thescattering topology of plane waves inthe context of joint finite-difference,time-domain, frequency-domainanalysis.

Publications

Other

Cameron, S. M., and R. D. Robinett, III.1998. “Adaptively ReconfigurableGround–Based Remote-Sensing Systemfor Monitoring Migrating Chemical/Biological Plumes and Detection ofUnderground Structures.” DARPAproposal in response to BAA 98-18(miniature, unattended ground sensorsand related technologies) (25 Febru-ary).

Cameron, S. M., R. B. Asher, G. M.Loubriel, R. D. Robinett, III, K. M.Stantz, M. W. Trahan, and J. S. Wagner.1998. “Adaptive Remote-SensingTechniques Implementing Swarms ofMobile Agents.” Paper presented toWSD ’98, 4th Joint Workshop onStandoff Detection for Chemical andBiological Defense, Williamsburg, VA,30 October.

Stantz, K. M., C. G. Diniz, M. W. Trahan,and J. S. Wagner. 1998. “CharacterRecognition Using Genetically TrainedNeural Networks.” Sandia TechnicalReport SAND98-2145 (October). SandiaNational Laboratories, Albuquerque,NM.

Stantz, K. M., S. M. Cameron, G. M.Loubriel, M. W. Trahan, and J. S.Wagner. 1998. “Optical CommunicationSystem for Remote Monitoring andAdaptive Control of DistributedGround Sensors Exhibiting CollectiveIntelligence.” Sandia Technical ReportSAND98-2752 (November). SandiaNational Laboratories, Albuquerque,NM.

Stantz, K. M., S. M. Cameron, M. W.Trahan, and J. S. Wagner. 1998.“Adaptive Remote-Sensing TechniquesImplementing Swarms of IntelligentMobile Agents Guided by Physics–Based Models.” Technical Advance SD-6225 (21 July).

Trahan, M. W., J. S. Wagner, K. M.Stantz, P. C. Gray, and R. D. Robinett,III. 1998. “Swarms of UAVs and FighterAircraft.” Paper presented to ICNPAA,The International Conference onNonlinear Problems in Aviation andAerospace, Daytona Beach, FL, 29April.

Wagner, J. S., and M. W. Trahan. 1998.“A Method of Designing, Controlling,and Simulating the Collective Behaviorof Autonomous, HeterogeneousActors, Robots, UAVs and MobileVehicles.” Technical Advance SD-6230/S-91404 (5 August).


3534.020

Low-Cost Cadmium ZincTelluride Radiation DetectorsBased on Electron-Transport-Only Designs

J. C. Lund, N. R. Hilton, B. A. Brunett, E.Y. Lee

The goal of this project is to utilizea novel device design to build acompact, high-resolution, room-tempera-ture–operated semiconductor gamma-ray sensor. Sandia constructed thisimproved sensor from a cadmium zinctelluride (CZT) crystal. It was able toboth detect radiation and determine theparticular isotopes responsible for theemitted radiation. CZT detectorsproduced today have excellent electroncharge carrier collection, but suffer frompoor hole collection. For conventionalgamma-ray spectrometers, both theelectrons and holes must be collectedwith high efficiency to preserve energyresolution. The requirement to collectthe hole carriers, which have relativelylow lifetimes, limits the efficiency andperformance of existing experimentaldevices. By implementing novel devicedesigns such that the devices rely onlyon the electron signal for energyinformation, we substantially increasedthe sensitivity of the sensors for detect-ing radiation. The availability of newCZT sensors with enhanced sensitivitywould find immediate application in thesafeguarding of stored nuclear materials,detecting nuclear smuggling andweapons facilities, enhancing arms-control and treaty-verification opera-tions, detecting landmines andunexploded ordnance (UXO), and

improving environmental monitoringand remediation activities.

We designed, built, and testedseveral electron-only devices of twogeneral new designs. We also devel-oped computational methods fordesigning devices. These computa-tional methods are a vast improvementover the qualitative methods used todesign our first device and allowed usto design optimized device structures.The computational methods include afull 3-D finite-element code and asimpler 2-D code for rapid executionand quick idea trials. We developedexperimental methods to characterizethe behavior of the devices and thecrystalline semiconductor materialfrom which the devices were built.These experimental methods includedtechniques to map the electrical andtransport properties of the crystalused to construct the device. We alsodeveloped a method of reading outthese new devices that provides bothposition resolution and pulse-heightenergy resolution. We also developed anovel method for rejecting unwantedsignals arising in the detector, whichwas simple to implement yet extremelyeffective.

Publications

Refereed

Yoon, H., J. M. Van Scyoc, M. S.Goorsky, H. Hermon, M. Schieber, J. C.Lund, and R. B. James. 1997. “Investi-gation of the Effects of Polishing andEtching on the Quality of CadmiumZinc Telluride Crystals and DetectorsUsing Spatial Mapping Techniques.” J.Electron. Mater. 26 (December): 529–533.

3535.150

Novel Materials for HydrogenStorage

B. P. Somerday, S. E. Guthrie, R. A.Causey

A professor at Chuo Universitydemonstrated that exposure of nickel(Ni) to extremely high-pressure (5 GPa,diamond anvil) hydrogen (H) and hightemperature (800°C) produces amaterial with up to 20% isolatedvacancies. Such atomically porousmaterials have potential applications asH-storage devices. Sandia is investigat-ing the feasibility of producing anatomically porous structure in a low-density material such as aluminum (Al).In addition, we will identify the salientfactors that affect the stability ofatomically porous materials by examin-ing a well-characterized system, i.e., Ni.This work relies on numerical simula-tions to assess the stability of theatomically porous Al and Ni structures.

We conducted numericalsimulations of Al and Ni latticescontaining high concentrations ofvacancies (0.05 to 0.20 vacancies/lattice site) using the Embedded AtomMethod (EAM). The salient conclu-sions are as follows:

• High-vacancy concentrationscause the Al lattice to disorder at300°K. Al is not a viable candidate fordevelopment as an atomically porousH-storage material.


• Vacancy concentration and Hcontent are important variables indetermining the lattice stability of Ni at300°K.

– Ni retains the face-centeredcubic structure for vacancy concentra-tions up to 0.15/lattice site, but latticeswith 0.15 vacancies are more stablethan lattices with 0.10 or 0.20 vacan-cies.

– Ni lattices with 0.15 vacanciesare more stable with random vacan-cies compared to ordered vacancies.This finding is contrary to experimen-tal results that suggest the stablestructure in Ni is an ordered array ofvacancies.

– Ni lattices with 0.15 vacanciesexhibit rotations. This unexpectedresult may provide insight into thebehavior of other systems that containelevated vacancy concentrations, i.e.,heavily cold-worked structures.

• Lattice structures of Ni and Alcontaining vacancies and H are lessstable compared to structures withvacancies only at 300°K.

Publications

Other

Somerday, B. P., and M. I. Baskes. 1998.“Numerical Modeling of the Stability ofFace-Centered Cubic Metals with High-Vacancy Concentrations.” Presentationto Hiroshima University (Invited),Hiroshima, Japan, September. SandiaTechnical Report SAND98-8624A.

3535.170

Inversion of PassiveElectromagnetic Fields toLocate Weapons of MassDestruction

G. A. Newman, D. M. Day

Weapons of mass destruction(WMD) pose grave threats to thesecurity of the U.S. and the rest of thefree world. Identifying and locating thesefacilities are therefore of criticalimportance. Because many facilities areburied at depths greater than severaltens of meters, remote-sensing methodsmay be necessary for their detection.Here Sandia will focus on very lowfrequency (VLF) electromagnetic (EM)fields (< 10k Hz) to detect, locate, andcharacterize WMD facilities. The use ofVLF fields is required since the Earth is ahigh-loss medium, and higher-frequencyfields such as synthetic aperture radar(SAR) cannot effectively penetrate to therequired depths. While passive seismicmonitoring methods are currently underinvestigation for the WMD problem, theuse of VLF fields is also now receivingattention.

Two types of VLF passive mea-surements are most promising fordetecting WMD facilities. The first,addressed by this project, uses naturalVLF emissions or magnetotelluric (MT)fields that arise from interaction of thesolar wind with the Earth’s ionosphere.The second employs emissions from thepowerlines directly feeding the facility.

A major obstacle in employingpassive VLF fields to image WMDfacilities has been the inability tointerpret the data. The observed VLFfield depends on both the facility and thelocal geology. To accurately locate andcharacterize the facility, we must alsocharacterize the geology. Unfortunatelythe facility response is coupled to thegeology in a nonlinear fashion, and thegeology, including the topography, ofWMD sites is often complex and rugged.Another problem is that the (minimal)

amount of data sufficient to reliablycharacterize and locate buried WMDfacilities is unknown. Data sets withhigh spatial sampling are desirable, butare not practical to collect.

We carried out a resolution studyto examine the applicability of usingpassive MT fields to locate andcharacterize facilities housing WMD.The key questions this studyattempted to answer were (1) theability to locate buried facilities in thepresence of topography and localvariations in near-surface geology, and(2) the minimum amount of data andquality necessary to characterize WMDfacilities. Using nonlinear 3-D optimiza-tion techniques, we found that a singleMT sounding, if properly located, canrecover critical information on facilitylocation, including its depth of burial.To provide enhanced resolution,however, requires much greater fieldsampling, which may not be practical.The findings also demonstrated that ifsounding stations could be set up onthe perimeter of a facility such that thesounding stations surround the facility,it is also possible to infer criticalinformation on facility location and itsdepth of burial. Results from thisinvestigation show that the use ofpassive MT fields to locate andcharacterize WMD facilities hassignificant potential.

Publications

Refereed

Newman, G. A., and D. L. Alumbaugh.1998. “Three-DimensionalMagnetotelluric Inversion UsingNonlinear Conjugate Gradients.” Proc.Copper Mountain Conf. on IterativeMeth. II (Copper Mountain, CO, 30March–4 April): 1.

Other

Newman, G. A., and D. L. Alumbaugh.1998. “Three-DimensionalMagnetotelluric Inversion UsingNonlinear Conjugate Gradients.”Geophys. J. Internat., submitted.


3535.180

Z-Pinch–Driven IsentropicCompression

S. A. Slutz, J. R. Asay, R. B. Spielman

The attainment of controlledfusion has to be one of the grandchallenges of this century. The economicand environmental impact of commer-cial fusion would be enormous. In thenear term, inertial fusion would beinvaluable to the study of weaponsphysics and effects in the absence ofnuclear testing. The achievement ofinertial confinement fusion (ICF)requires the compression of hydrogenisotopes (deuterium-tritium [DT]) tohigh density and temperatures. Highdensities can be achieved most effi-ciently by isentropic compression, whichrequires relatively slow pressure pulses(~ 10-8 s). In contrast, high temperaturescan be reached most efficiently withshort, high-power pulses (~ 10-11 s).Z-pinches and lasers currently are beingdeveloped as alternative routes toinertial fusion. The purpose of thisproject is to determine if fusion could bereached more efficiently by using az-pinch to compress the fuel, and a laserto heat and ignite this compressed fuel.This approach would use the strengthsof these two technologies and coulddramatically reduce the cost of a high-gain inertial fusion facility, which isimportant for stockpile stewardship.Furthermore, isentropic compressioncould provide valuable equation-of-state(EOS) information at high pressures anddensities. This information is importantfor weapons physics, astrophysics, andplanetary interiors, and may provide ameans of generating new materialstates. We show that the laser energyneeded to ignite a propagating burn isproportional to the reciprocal of the DTdensity squared and that trapping alphaparticles with a magnetic field does notchange this result. We performednumerical simulations that indicate aquasi-spherical z-pinch implosion usingmagnetic flux compression can effi-

ciently compress DT to high densities.Furthermore, we performed experimentsshowing that high currents can bedelivered to loads the small size of ICFtargets.

The minimum hot-spot energyrequired for ignition is determined bythe requirement that a significantfraction of the alpha particles beabsorbed within the hot spot. Thus theradius of the hot spot, Rh < Ra/r, wherethe range of an alpha particle, Ra ~ 0.4gm/cm2. The hot-spot mass is Mh=(4/3)prr3. The temperature of the hot spotmust be raised above the ideal ignitiontemperature. Assuming 3 kT/2 ofenergy/particle at 10 keV, the minimumhot-spot energy is Eh=320/r2 MJ. Thisyields approximately 3 kJ at a density1200 times the solid density of frozenDT. Numerical simulations indicatethat hot electrons can be generated atabout 40% efficiency by a high-intensity laser, Il2 = 1020 W cm-2 mm2.Thus at this density approximately 7.5kJ of laser energy would be required.This laser energy must be delivered inless time than the hot-spot disassem-bly time, tD ~ Ra/csr, which is about 10ps at r = 300 gm/cm2.

The natural geometry of z-pinchimplosions is cylindrical. The conver-gence ratio h = r0/r is limited by theRayleigh-Taylor instability. Values of10–20 are generally believed to bepossible, even assuming h = 20, Eh ~ 40kJ, which would require approximately100 kJ of laser energy. This is a ratherlarge laser. We considered the applica-tion of a strong magnetic field toinhibit the transport of the alphaparticles and thus lower the hot-spotenergy requirement. Numericalsimulations show that although thegain within the hot spot is improvedby the presence of the magnetic field,the propagation of the burn into thesurrounding cold fuel is inhibited. Weconclude that high densities areneeded to keep the laser energy at anaffordable level.

High densities with acceptableconvergence ratios can be achievedonly with quasi-spherical z-pinch

implosions. Numerical simulationsshow that the current profile typical ofa pulsed-power accelerator does notproduce an isentropic compressionbecause the current rises too quicklyearly in the pulse and not fast enoughlate in the pulse. This generates shockwaves that increase the entropy of thefuel, and relatively low densities areobtained. Analytic modeling andnumerical simulations show that anappropriate current profile can begenerated by a z-pinch compressing apreviously generated magnetic field.This is termed flux compression andworks in a manner analogous toexplosive generators. Ideal 1-Dsimulations of this approach yieldcompressed fuel densities of 300 gm/cm2, with an accelerator drive currentof only 20 MA, which can be deliveredby the Z-accelerator. Of course, 2-Deffects will degrade this performance,but the approach looks promising.

Current must be delivered to avery small load (1–2 mm) as comparedto typical z-pinch loads, with an initialradius ~ 1 cm. To address the power-flow issue, we carried out experimentsdriving small cylindrical targets.Current was efficiently delivered to a 3mm-radius tube. We diagnosed thepressure generated by the magneticfield near the tube using VISAR(velocity interferometer system forany reflector). For the first time, weobserved high-pressure phase transi-tion data in iron. These data indicatethat valuable EOS information shouldbe attainable with this technique.Further shots to measure isentropiccompression are in the shot schedule.

Publications

Refereed

Slutz, S. A., R. Spielman, and J. Asay.1999. “Z-Pinch–Driven IsentropicCompression for Inertial Fusion.” Proc.8th Internat. Conf. on Megagauss Mag-netic Field Generation and RelatedTopics (Tallahassee, FL, 18–23 Octo-ber).


3535.190

Covert, DistributedBiosensors for UXO/CWBased on AmplifiedImmunoassays Conducted inPorous Inorganic Media

C. J. Brinker, C. S. Ashley, A. K. Singh, J.S. Schoeniger, R. J. Simonson

Sandia’s goal in this project is todemonstrate a revolutionary bio-inorganic sensor for UXO/CW(unexploded ordnance/chemicalwarfare) with the potential to combinesample preconcentration, molecularrecognition, amplification, and opticaltransduction in a porous, inorganicmedia (SiO2 aerogel or xerogel) with norequirement for external power. Thisapproach exploits the unparalleledselectivity and sensitivity of antibody/antigen molecular recognition andamplified luminescent immunoassays(ALI) with the advantage of deploymentby practical, dispersible means. Weprepared samples in granular form foranalysis by immunoassay of their localvapor or liquid environment. Weincorporated commercially availableantibodies along with correspondingantigen-enzyme complexes and dyeprecursors into a silica gel host usingbiocompatible aqueous processing. Weexamined enzyme activity and enzyme-catalyzed dye production over the rangeof relative humidities encountered inreal-world environments. We identifiedcommercial assays for the specificdetection of small analytes that may besimilar in size and solubility to commonUXO agents and determined assaydetection limits.

This project focused on threemajor areas: (1) development of a sol-gel host matrix compatible (i.e., withregard to structure and chemistry)with biomolecules of interest, (2)stability of host-enzyme-dye systems,and (3) identification, synthesis, andincorporation of TNT-specific enzymesystems and assay methods.

Specific accomplishmentsinclude the following:

(1) We established synthesismethods of an inorganic silica matrixfor encapsulation of enzymes. Theseaqueous sol-gel processing methodscompletely eliminate the use of alcohol(deleterious to most biomolecules) aswell as the formation of alcohol as areaction by-product. We demonstratedenzyme-catalyzed dye production,which signals the formation of theenzyme-substrate complex, andresponse amplification of the dyesignal. Enzyme-doped aerogels,prepared using the aqueous sol-gelprocess, showed bioactivity followingprocessing. Retention of activity iscritical in biosensor applicationswhere the sensor is exposed to a rangeof temperature and humidity condi-tions.

(2) We dried silica gels (aerogelsand xerogels) containing encapsulatedenzymes and dye precursor moleculesat humidities ranging from 1%–50%.The enzymes retained completeactivity over a three-week period.

(3) To test the concept of vapor-phase sensing with these sol-gelsensors, we incorporated alcoholdehydrogenase into the silica matrix.This enzyme, which catalyzes reactionwith alcohol, showed bioactivity whenencapsulated within the inorganic sol-

gel matrix and exposed to alcoholvapor. To extend this work to UXOapplications, we identified commercialassays for the specific detection ofsmall analytes that may be comparablein size and solubility to common UXOagents. EMIT assays are specificallydesigned for detection of analytes withmolecular weights < 2000 daltons.EMIT assays have extensive applica-tions in drug screening (e.g., digoxin,theophylline) and are robust to thepresence of complex sample matricessuch as blood, plasma, or urine. Weused digoxin as a model analyte andmodified the commercial assay towork in solution in a format directlyapplicable to our sensor format. Thedetection limit demonstrated in thistest was 0.2 ng/ml, which correlateswell with 0.1–0.5 ng/ml reported in theliterature for systems using automatedanalyzers. We also identified a com-mercial source for specific antibodiesagainst TNT and various TNT-enzymeconjugates. We synthesized a TNT-glucose PDH (phosphate dehydroge-nase) conjugate (the enzyme of choicefor most commercial EMIT assays) forpotential use in a modified EMIT assayfor TNT.

Publications

Refereed

Bhatia, R. B. (UNM), C. J. Brinker, C. S.Ashley, and T. M. Harris (U. Tulsa).1998. “Synthesis of Sol-Gel Matrices forEncapsulation of Enzymes Using anAqueous Route.” Organic/InorganicHybrid Materials, Proc. MRS (SanFrancisco, CA, 13–17 April).


3535.210

Semiconductor FilamentLasers

F. J. Zutavern, S. M. Cameron, G. L.Benavides, A. G. Baca

Miniature, short-pulse lasers arebeing developed for use in at least threegeneral applications that are veryimportant to Sandia: (1) active opticalsensors for Defense Programs (DP) andDoD weapons systems in limited-visibility environments (optical fuzing,LADAR [laser radar], 3-D imaging, andsecure communications), (2) directoptical ignition (DOI) of fuels andexplosives for military and commercialapplications, and (3) micromachiningmicron-size features patterned overlarge areas of metals and alloys. Atpresent, the highest-energy short-pulsesemiconductor lasers deliver only 100 nJin 100 ps and 130 mrad.

Sandia will make a new type ofhigh-beam-quality semiconductor laserthat can potentially produce over 1000times more peak-power or short-pulseenergy than the conventional semicon-ductor laser. We would create these newlasers from the current filaments that areformed in high-gain photoconductivesemiconductor switches (PCSS). Low-field, avalanche-carrier generation is themechanism by which lightning bolt-likechannels of high-density, charge-neutralplasma are formed across the semi-insulating gap of the switch. We plan tomake a completely revolutionarysemiconductor laser from the electron-hole plasma inside these filaments.

We tested this new concept bybuilding some devices that allowed us toproduce a filament in a reflecting cavityand observe optical emission from theends of the current filaments. Wemeasured the optical and electricalproperties of these devices and obtainedvery convincing evidence of lasing. Wesee low divergence (2.5 degrees), highenergy (30–100 nJ), spectral (0.5 nm),and temporal (0.5 ns) narrowing, whichare characteristic of lasing. However, theconclusive test is to resolve the lasermode structure. Because these lasers arelarger than conventional semiconductor

lasers, their modes are much closertogether, and we were not able toresolve them with our presentspectrometer.

We have started to test this newconcept with some small devices thatallowed us to produce a currentfilament in a reflecting cavity andobserve optical emission from theends of the filament. When we fabri-cated our first devices, we encoun-tered stability problems with filamentformation and contact degradation. Wesignificantly improved stability byreducing the optical trigger imagewidth from approximately 200 to 30microns. We significantly improvedcontacts to high-gain PCSS with a deepdiffusion process.

From the end of a 20–40 Acurrent filament, we observed a roundspot of light being emitted from theedge of the switch with relatively lowdivergence (2.5 degrees). The spot is50–75 microns in diameter andapproximately 50 times brighter thanthe emission that we observed fromthe surface of the switch. We measured75 nJ emitted from one end of thefilament in a subnanosecond pulse.This is more energy than has beenobtained from the highest-energy,short-pulse conventional semiconduc-tor lasers (CSL). (Wide-stripe, edge-emitting lasers can produce 10–50 nJin subnanosecond pulses.) Thesemiconductor filament laser appearsto be Q or gain switching because itspulsewidth is less than 500 ps, whilethe current pulse that forms thefilament is 18 ns wide. We claim onlystrong evidence because the acceptedcriterion to demonstrate lasing is theresolution of cavity mode structure inthe optical spectrum. Our spectrumshows an instrument-limited linewidthof 0.5 nm or 0.7 meV. The modespacing for this 1 mm-long cavity is 0.1nm, which is presently beyond thecapability of our spectrometer.However, the spontaneous surface-emission spectrum is 50 nm wide dueto the high temperature of the carriersin the filaments. The most likelyexplanation for this narrowing islasing.

3537.010

Development of MembraneDevices Using AlN and SiCFilms

W. K. Schubert

The objective of this project is todevelop membrane devices for sensorapplications. Researchers at Sandiashowed that thin, freestanding mem-branes can be fabricated on silicon (Si)substrates. Using an appropriatetransduction scheme, the membrane canbe excited into a resonant mode. Sincethe membrane’s resonant frequency isextremely sensitive to membranetension and areal mass density, it can beconfigured as a sensor for pressure,strain, acceleration, or chemical species(using a sorptive film).

Researchers at Howard University(HU) developed deposition processesfor crystalline aluminum nitride (AlN)and silicon carbide (SiC) films. Whenthe AlN layer is oriented with c-axisnormal to the surface, it is piezoelectricand can be used, along with an interdigi-tated electrode pattern, to form atransducer on the resonant membranestructure. SiC is an extremely tough layerthat can be used as a support for the AlNlayer to form thin, freestanding mem-branes. SiC films can also serve as anetch-mask layer for the siliconmicromachining required to fabricatethe sensors. Alternatively, using a newmagnetic excitation scheme thatobviates the need for a piezoelectriclayer, the nonpiezoelectric SiC layercould be used alone to form the mem-brane device. This excitation schemerelies on Lorentz forces generated by thecurrent lines on the membrane incombination with an externally appliedmagnetic field.

Researchers at HU, in collabora-tion with Sandia, developed a photo-lithographic mask set to implement theprocess of depositing SiC thin filmsranging from 0.6 to 1.2 microns inthickness on 50 mm-diameter silicon(Si) wafers. Sandia wants to develop aprocess flow for fabricating flexuralplate-wave (FPW) devices. Thisprocess involves bulk micromachiningof the Si wafer using an anisotropic


etch solution (potassium hydroxide[KOH]) to release the precisely sizedSiC membrane from the underlying Si.The area exposed to the KOH solutionis defined with a photopatternedchrome/gold-masking layer on thebackside of the wafer. We will definemetal transducers used to impose astanding FPW on the front side of thereleased membranes. Process optimi-zation of the membrane definition andrelease steps has begun.

In addition to the processdevelopment, we received two SiC-coated wafers for fabrication of FPWdevices using existing photomasks.The Sandia process will define themetal transducers on the front sidefirst, then use a photoresist mask anddry-etch process to release themembranes. We are currently testingminor adjustments to the membranerelease process required to accommo-date the SiC film. (Sandia’s FPWdevices normally use silicon nitride[SiN] films.)

The objective of this project wasto test the suitability of SiC and AlNthin films for use in FPW devices. Wehave not yet met this objective,although we have made progress.Earlier work on these materialsdeposited the films in small researchreactors on substrates that were toosmall for meaningful process develop-ment (about 1 cm). We succeeded intransferring the SiC process to larger-scale reactors and producing filmswith reasonable thickness uniformityon 50 mm-diameter wafers. We havebegun the work required to test thesuitability of the SiC films for FPWdevices. Critical questions that mustbe answered to determine suitabilityinclude whether or not the films arecompatible with the bulk micro-machining methods used to release themembranes, and whether intrinsicstress levels in the films are compat-ible with membrane devices. If thefilms are under compressive stress,they will buckle when released, andthe FPW device will not function. Ifstress levels are tensile but too high,the films fracture when the underlyingSi is removed. The quality factor ofFPW devices (resonant frequency/bandwidth) is highest when the

membrane stress is below 100megapascals.

These questions will beanswered for the SiC films when thefirst membranes are released.

3537.020

Spectral Information Contentin Ion-Mobility Spectra forExplosives, Interferants, andOther Negative-IonizingChemicals

J. E. Parmeter

Ion-mobility spectrometry (IMS) isone of the most powerful techniquescurrently available for the trace chemi-cal detection of several importantclasses of compounds, includingexplosives and drugs. In IMS, analytemolecules are first ionized, thenidentified based on their time of flight(TOF) through an electric field. Attrac-tive features of IMS include parts-per-trillion sensitivity, good selectivity, andnear instantaneous response time.However, theoretical understanding ofIMS lags behind practice, and there iscurrently no known way to abstract froman unknown IMS spectrum informationabout the type of molecule represented.However, some recent work at NewMexico State University (NMSU)indicates that it may be possible toabstract information on the chemicalmoieties present in an IMS spectrum byusing artificial intelligence (AI) toolssuch as neural networks. In collabora-tion with NMSU, Sandia will focus onnegative-ion IMS spectra (the mode ofoperation relevant to explosivesdetection), and investigate the ability oftrained neural networks to classifyspectra of chemicals that the networkshave not been exposed to duringtraining.

(1) To initiate the project, weconstructed an experimental appara-tus consisting of an IMS interfaced to agas chromatograph (GC). The use ofthe GC allowed IMS spectra of testcompounds to be obtained withoutconcerns about interference fromimpurities, since the GC afforded ameans of prefractioning the sample

and delivering clean standards to theIMS. In the experiments carried out inthis study, we ran the IMS at 160°Cusing carbon-tetrachloride reagentgas.

(2) We developed a referencelibrary of negative polarity IMS spectraby obtaining spectra for 13 chosencompounds: o-nitrophenol, p-nitrophenol, 2,4-dinitrophenol,2-nitrotoluene, 4-nitrotoluene, 2,4-dinitrotoluene, 2,6-dinitrotoluene,3,4-dinitrotoluene, 1-chloro-2-nitroben-zene, 1-chloro-3-nitrobenzene,1-chloro-4-nitrobenzene, pentachloro-nitrobenzene, and 2,4,6-trinitrotoluene.In most cases, we obtained 8–15 IMSspectra at different concentrations foreach compound. The resulting librarycontains a total of 163 original IMSspectra for study using neural net-works. The spectra followed reason-able interpretations of structure andstability for the ions created for eachchemical.

(3) We used over 150 spectrafrom 13 chemicals (drawn from theGC/IMS library created here) to train aneural network, using a 400 MHzPentium–based computer andNeuralWare II software.

(4) We subsequently challengedthe neural net with additional spectrafrom the library, which had notpreviously been seen by the neuralnet, and attempted chemical identifica-tion. We found that the neural networkwas able to successfully identify thesespectra as to compound. Thus, thesystem was able to use AI to identifyIMS spectra of a given compound atone concentration, when the networkhad already been trained with aspectrum of the same compound at adifferent concentration.

(5) In another set of studies, wetrained the network according tochemical class (nitrotoluenes,nitrophenols, and chloronitroben-zenes). The purpose of this training isto conduct experiments to seewhether the neural network canclassify compounds whose spectra ithas never seen (at any concentration)according to chemical class. Prelimi-nary results suggest that this ispossible.


3537.040

Picosecond Particle VelocityMeasurements

K. G. Holland

Sandia plans to develop anexperimental capability to obtainsubnanosecond particle velocitymeasurements in single-event shock-wave experiments. Such a capabilitywill permit examination of fast transientphenomena at the continuum level incollaboration with the picosecondoptical spectroscopy work being carriedout at Washington State University(WSU).

Currently, we use both EMV(electromagnetic velocity) gauges (~ 10ns risetime and restricted to nonmetallicsolids) and laser interferometry (VISAR[velocity interferometer system for anyreflector]) developed at Sandia toobtain particle velocity histories inshocked samples. The time resolution ofelectronic recording VISAR measure-ments is currently limited to 1–2 ns.

The development of asubnanosecond-velocity recordingcapability will enable strong interactionswith comparable efforts currently underway in Sandia’s shock physics programs.

The configuration used toacquire signals on the streak camerafrom the existing VISAR systemconsisted of the following compo-nents. We placed a beam splitter neareach of the three photomultipliertubes (PMTs) such that a portion ofthe light incident on the PMT photo-cathodes was diverted to a lens-coupled optical fiber (100/140-microncore/clad diameter, 0.29 numericalaperture [NA] gradient index fiber).The fibers from the two VISAR signallegs were equal length (230 cm), andthe fiber carrying the beam intensitymonitor (BIM) signal was 305 cm long,to compensate for the propagationtime delay in the signal legs relative tothe BIM sample location. We cementedthe three fibers into a brass block in alinear array and polished the signal legfibers on either side of the centeredBIM. The assembly was mounted onthe streak camera frame and the fibers

imaged onto the streak cameraphotocathode with a Nikon 50 mm,f/1.4 lens at 1:1 magnification. Thisconfiguration allowed for simultaneousrecording of VISAR data via the streakcamera and the PMTs.

The charge-coupled device(CCD) ordered for use in this systemdid not arrive in time to be used forthe feasibility demonstration; instead,we mated an existing CCD and imageintensifier to the IMACON 790 streakcamera for the test shot. The CCDarray consisted of 24-micron squarepixels on a 1024 x 1024 array. Theimage of each input fiber had a five-pixel full-width half-medium (FWHM) inthe two orthogonal directions. At thesetting selected for the first test shot,the overall streak rate on the CCD was1.12 ns per pixel over an 800 nsrecording window.

We used a simple impactor/target configuration in the feasibilitydemonstration shot. The lapped frontsurface of an aluminum (Al) projectileimpacted a nominal 3 mm-thick Al disk,which was backed by apolymethylmethacrylate (PMMA)window. The PMMA window had ahighly specular mirror surface at thePMMA/Al interface. The shot was firedin the ISP 2.5-inch light-gas gun. Theexpected velocity profile of themonitored surface consisted of thearrival of an elastic precursor followedby a plastic wave approximately 80 nslater, with a final particle velocity of0.32 mm/msec within the recordinginterval. The streak/CCD records werefit by eye to a quadrature ellipse. Wereferred to the PMT records forguidance in the fit analysis, but did notuse them to correct the velocity profileobtained from the streak data. Theresulting velocity histories obtainedvia the two recording techniquesshowed excellent agreement in eventtiming and velocity magnitude. Thelargest deviations occurred after thefinal velocity was nearly reached, withmaximum deviations of approximately3%. The mean values for the finalvelocity plateau from the two measure-ments agreed to 1.3%.

We did not realize the highestpossible time resolution in this first

feasibility demonstration, but the testwas nevertheless successful. Furtherwork will consist of adapting the newCCD, improving the camera streak ratethrough the purchase of a faster plug-in streak unit, reducing the diameter ofthe coupling fibers, and optimizing thelight-coupling scheme for light-collecting efficiency.

3537.050

Particle-Level Modeling ofFlows of ConcentratedSuspensions

A. J. Hurd

It is well established that the flowof concentrated suspensions of particlescannot be modeled in a satisfactorymanner using currently availablemacroscopic constitutive equationsbecause particles in the suspension mayform structures that are flow-dependent.In addition, particle migration/segrega-tion may occur under certain conditions.Modeling the interactions between largenumbers of particles in a flowingsuspension is essential to understandthe above phenomena and to be able toconstruct accurate macroscopic constitu-tive equations. The boundary elementmethod (BEM) is ideal for solving thisclass of problem. However, untilrecently, large dynamic particle-levelsimulations were not practical due to theO(N2) to O(N3) scaling of the necessarycomputational resources. The applica-tion of fat multipole methods (FMM) tothe BEM results in O(N) scaling. Incollaboration with researchers at theUniversity of New Mexico, Sandia willuse FMM combined with the scalabilityof BEM for parallel processing to enablelarge-scale, particle-level simulations tobe performed.

We used the BEM to model theflow of highly loaded particle suspen-sions. This approach allows thesimulation of particles of any shape inarbitrary flow geometries. Currently,the simulations are in two dimensions;however, a 3-D code is under construc-tion.

The use of the BEM for thispurpose has so far been limited to


relatively small numbers of particlesdue to the high computational cost ofthis technique, which scales as N2,where N is the number of collocationpoints used in the boundarydiscretization. In this work, we used amultipole acceleration technique toreduce the computational cost fromO(N2) to O(N log N). This allows thesimulation of much larger systems.

The ability to simulate largenumbers of particles is essential inunderstanding the macroscopicbehavior of suspensions. Being able tosimulate large systems eliminates theneed for repeat cell simulations, whereeffects such as structure formationmay be artificially induced.

The solution of boundaryintegral equations using the BEMinvolves the calculation of integrals,which become nearly singular whenthe collocation point is very close tothe surface where the integration istaking place. This situation is inevita-bly encountered in the simulation ofhighly concentrated systems. A largepart of the current work was thedevelopment of coordinate transfor-mations that provide accurate integra-tions by reducing the singularity withappropriate jacobians. The efficacy ofthis technique is demonstrated by thequality of solutions produced by thesimulations. The error in the calcula-tion of the velocity for each particle isless than one percent with a 12-nodeparticle discretization.

A practical application ofimmediate concern is the simulation ofthe extrusion of highly loaded suspen-sions of fine ceramic particles. Thistype of operation is used to producecomplex-shaped ceramic componentswithout the use of a mold. Because ofthe size of the particles, Brownianforces and colloidal forces act on eachparticle in the suspension in additionto the hydrodynamic interactions. Weadded the capacity to model suchforces, as well as body forces such asgravity, to the BEM code.

We performed initial simulationsusing a wide-gap Couette geometry.Experimental data are available for thistype of geometry, and the BEM codecorrectly predicted experimentally

observed phenomena such as irrevers-ible particle migration. We alsocorrectly predicted sedimentationpatterns. The shape of the sedimentedparticle bed predicted by the BEMcode is very similar to the experimen-tally determined shape.

Currently, we are implementinggeometries of more practical interestfor the abovementioned application. Inparticular, the flow of a highly loadedsuspension through a contraction is ofimmediate interest. In addition, the 3-Dversion of the BEM code is underdevelopment. While 2-D simulationshave been shown to provide accuratequalitative predictions, quantitativepredictions will require fully 3-Dgeometries.

Publications

Other

Mammoli, A. I. 1998. “Particle-LevelModeling of Flows of ConcentratedSuspensions.” Web site www.unm.edu,September.

3537.060

Efficient Processing ofMaterials Microstructureswith Intelligent FeatureExtraction for QuantitativeStereology

E. A. Holm

In collaboration with LehighUniversity, Sandia will develop method-ologies for the analysis of electronmicrographs that will substantiallyenhance the acquisition of terascalemicrostructural information (e.g.,distributions of grain size and shape) ina variety of systems. This project seeksto dramatically improve on the currentsituation by creating new deterministicand stochastic algorithms of sufficientgenerality that mitigate the contrastambiguities peculiar to a number ofmicroscopies. Such algorithms willnecessarily complement many existingimage-processing techniques and will beemployed in conjunction with them to

develop robust, systematic, automatedtools. This research addresses the issueof image data reduction in the use of theAccelerated Strategic ComputingInitiative’s (ASCI’s) microstructuralevolution models.

The primary difficulty in analyz-ing and interpreting transmissionelectron micrographs (TEM) is thatcontrast variations in these images areoften complex, owing to multiplecontrast sources, which results in alarge amount of spurious information.This project focuses on developingcomputational algorithms that mini-mize and eliminate erroneouslyidentified microstructural features.Our strategy for attacking this problemincludes both standard image-processing techniques and our ownimage filters, combined in optimal andnovel ways. We utilize standard noisereduction, edge, and thresholdingfilters with newly developed auto-mated thresholding, segment, tangle,and cluster filters. We developed thenew filters with the geometry andtopology of grain structures in mind.The microstructural investigation ofsome metallic systems presentsadditional challenges due to highproportions of low-angle twin bound-aries, which should not be consideredin a grain-size or topology analysis. Webegan work in developing new filtersthat use the geometric and topologicalcharacteristics of twins to eliminatetwin boundaries during automatedimage analysis.

Publications

Refereed

Carpenter, D. T., J. M. Rickman, and K.Barmak. 1998. “A Methodology forAutomated Quantitative Microstruc-tural Analysis of Transmission Elec-tron Micrographs.” J. Appl. Phys.,accepted.


3537.030

Magnetic Field ProfileMeasurements in Wire-ArrayZ-Pinches by FaradayRotation

R. B. Spielman

This research was directed towardthe implementation of laser–baseddiagnostics for wire-array z-pinches.Sandia was able to carry out all thenecessary preparations to set up thelaser diagnostics to complement ourx-ray backlighting measurements of theearly phase of exploding-wire z-pinchplasma formation.

These new diagnostics willaugment the capabilities of our presentx-ray backlighting diagnostic to allowsimultaneous laser illumination andx-ray backlighting of wire plasmas.Initially, schlieren imaging and interfer-ometry with the laser will allow mea-surement of lower plasma densities thanthe x-ray backlighter. Eventually wehope to implement polarimetry (Fara-day rotation) to determine the magnetic-field profile and therefore the currentdensity profile flowing in the wireplasmas.

Diagnostic development. Wedetermined the laser parametersneeded for these laser–based tech-niques in combination. Although thenominal minimum laser pulsewidth is 4ns, we were able to arrange with themanufacturer for an operating proce-dure that permits a 2 ns pulse infrequency-tripled light to be includedwithin the warranted operatingconditions because of our low in-tended pulse repetition rate (1 pps).

The Nd-YAG laser is set up tooperate in either the fundamental,first, or second harmonic modes, andwe can also use any of them incombination. After we establishedsatisfactory laser operation in the firstharmonic, we made measurements of

laser-trigger throughput delay todetermine possible approaches for thedesign of a system to trigger the laserwith minimum possible time jitter withrespect to the wire-array current pulseand the x-ray backlighter. This designwas not straightforward because thislaser, which was the only one availablewithin our budget constraint havingthe required optical parameter for ourapplications, is supplied only in aconfiguration that is intended to beused in a free-run, repetitive-pulsemode of operation. However, we mustsynchronize a single laser pulse withthe x-ray backlighter pulsed-powersystem. We chose a design for thetrigger system that selects a pulsefrom the free-running repetitive firingof the laser flashlamp to trigger thewire-array current pulse and the x-raybacklighter driver when both are fullycharged. The trigger for the laser Q-switch (Pockels cell) is then generatedfrom a current monitor located afterthe main output switch of the x-raybacklighter driver, which minimizesjitter between the backlighter and thelaser. We determined that the Pockelscell-trigger throughput delay is justshort enough to allow this ideal low-jitter mode of operation. This systemis presently under construction.

We were able to carry out all thenecessary preparations to set up thelaser diagnostics to complement our x-ray backlighting measurements of theearly phase of exploding-wire, z-pinchplasma formation. We are now takingthe initial steps to integrate the laserinto the existing experimental system.

Publications

Other

Greenley, J. B. 1998. “Faraday RotationMeasurements on Z-Pinches FinalReport.” Sandia Technical ReportSAND98-2372 (November). SandiaNational Laboratories, Albuquerque,NM.

3537.070

Nondestructive Evaluation ofWind Turbine Blades

T. W. Simmermacher

The failure of a wind turbine bladein the field is usually accompanied bydamage to other wind turbine compo-nents and sometimes to other windturbines. The event means loss ofrevenue, loss of equipment, usuallynegative public relations, and, at thevery least, a hit on the credibility of thewind turbine manufacturer. It would beadvantageous to avoid these outcomesaltogether. There will be an increasingneed, as a fleet of wind turbines ages, tobe able to assess the health of thestructures, particularly wind turbineblades.

Sandia is conducting an ongoingstudy in the nondestructive evaluation ofwind turbine blades. Efforts concen-trated on in-service evaluations thatcreate minimal interference withoperations in the field. Inherent in thesestudies is the need for algorithms thatwill quickly evaluate a set of data todetermine the structural state of a blade.

Modal–based evaluation tech-niques and algorithms developed atNorth Carolina A&T State Universityprovide a type of nondestructiveevaluation that is particularly well suitedfor structurally simple systems such aswind turbines. These methods utilizedata that are typically gathered in thecourse of a modal test. These datainclude frequency response functions(FRFs), mode shapes, damping, andnatural frequencies. Changes in thesedata, as compared to a set of assumedundamaged set of data, can indicate thepresence of damage and possibly thelocation of the damage. We can use thisinformation to signal a problem with aparticular blade that would indicate theneed for maintenance.


These techniques offer thepotential for application to weaponsystems and other more complicatedstructures. Changes in modal parameterscould indicate critical variations intolerances of such parameters as bolttension, metal fatigue of supportingbrackets, and debonds in the aeroshellof a reentry vehicle, for example.

We used a scanning laservibrometer and piezoceramic actua-tors to detect damage on a section of awind turbine blade. The laser is anoncontact sensor that can measurevibration at a large number of pointson a structure over a wide frequencyrange. We used piezoceramic patchesto generate the vibration without massloading the structure. We used threedifferent methods for detectingdamage, based on changes in transmit-tance functions, FRFs, and operationaldeflection shapes. We detecteddamage simulated by a steel plateclamped to the blade by the threetechniques.

This experiment indicated thefeasibility of using piezoceramicpatches for excitation and a scanninglaser vibrometer to measure vibrationto detect damage. To increase thefrequency range of the test andrepeatability, we could place a secondlarge piezoceramic patch on theopposite side of the blade and use aslower sweep input. A finer measure-ment grid would also increase theresolution of damage.

Publications

Other

Sundaresan, M. J., M. J. Schulz, J. Hill,E. A. Wheater, and F. Ferguson. 1998.“Damage Detection on a Wind TurbineSection.” Proc. 17th Internat. Modal Anal.Conf. 1 (Orlando, FL, 8 February 1999).

3537.080

Very Small Arrays: DesigningSelf-Assembled Systems ofLight-Antennae and ReactionCenters for ArtificialPhotosynthesis

J. A. Shelnutt

The goal of this project is todevelop structure-function relationshipsto guide computer-aided design (CAD)of improved molecular elements for verysmall arrays. The photosyntheticapparatus is composed of a reactioncenter protein, containing six porphyrin–based pigments and other moleculessurrounded by hundreds of similarporphyrins that act as a light antenna.The antenna collects light energy andfeeds the reaction center by energytransfer. These pigment molecules arehighly organized to bring about theefficient capture and conversion of lightenergy in the form of chemical fuels,principally ATP (adenosine triphos-phate). Researchers at Arizona StateUniversity (ASU) are developing highlyorganized structures that mimic thephotosynthetic apparatus. Theseamazing structures enable singletelectron transfer much like the pigmentsin the biological photosynthetic reactioncenter. Singlet transfer is importantbecause more of the light energyabsorbed by antennae pigments is madeavailable for conversion to chemicalenergy than for triplet electron transfer.In collaboration with ASU researchers,we will perform molecular simulationson porphyrin-fullerene electron-transportcomplexes and validate the calculationswith resonance Raman measurements.

We completed initial molecularsimulations of porphyrin-fullerene andporphyrin-porphyrin dyads and usedexperimental studies using resonance

Raman to validate the calculatedstructures of the dyads. For thefullerene systems, covalently boundfullerene-porphyrin dyads in which thenature of the porphyrin substituentswas varied were energy-optimized todetermine the stable conformations ofthe molecules. We performed similarmolecular mechanics calculations forwhich the porphyrin substituents werevaried for porphyrin-porphyrincovalently bound dyads. Theseincluded octaethyl-, etio-, and copro-porphyrins. We found multipleconformers for some of these dyads. Insome cases, the conformationalenergies are nearly equal, indicatingthe possibility that they will coexist atambient temperatures. Initial reso-nance Raman studies of the dyadsshow spectral differences that validatethe structural differences for differentporphyrin substituents. Thus, wedemonstrated the potential for usingresonance Raman spectroscopy incombination with molecular simula-tions methods for designing smallarrays.

Publications

Refereed

Ma, J. G., J. Zhang, R. Franco, S. L. Jia,I. Moura, J. G. Moura, P. M. H. Kroneck,and J. A. Shelnutt. 1998. “The Struc-tural Origin of Nonplanar HemeDistortions in TetrahemeFerricytochromes c3.” Biochemistry 37(1 September): 12431–12442.

Other

Ma, J. G., J. Zhang, R. Franco, S. L. Jia,and J. A. Shelnutt. 1998. “StructuralOrigin of the Nonplanar Hemes inCytochromes c3.” Papers of the Amer.Chem. Soc. 215 (Dallas, TX, 29 March):308.


3537.110

Enzyme-MediatedElectrochemical RedoxPolymer Biosensor for V- andG-Type Chemical Weapons

R. P. Janek, A. W. Flounders, K. Wally

This work seeks to furtherunderstand the direct intersection ofbiology and microelectronics. Thebenefits of such an understanding can beexploited to make robust sensors forbiological and chemical weapons (BW/CW). Nature has successfully solved theproblem of surviving in complexenvironments by miniaturizing task-specific enzymes and communicatingwith those enzymes via electronicpathways. One example of this schemeis the operation of the human brain. Thefield of bioelectronics is quite large and,although research efforts can require asubstantial investment in resources, thework proposed here can be executedreadily to yield high-quality informationabout the electrified interface. Sandiaplans to embed organophosphatehydrolase (OPH) in a matrix of siloxanepolymers containing naphthoquinone(NQ) and benzylviologen (BV) subunits.We will immobilize the polymers oncarbon electrodes exposed to a solutionof organophosphate. The NQ and BVform a redox couple that is capable oftransporting charge from the polymer tothe carbon electrode. This chargetransport mechanism is mediated by thelocal pH of the polymer network. If anorganophosphate agent is present, theOPH will hydrolyze this compound toform protons and therefore change theconductivity of the polymer.

The OPH enzyme used in thisstudy is available from an internalSandia source, as are methods fortesting the electrical properties of theelectrode materials. We will synthesizethe redox polymer in collaboration withthe University of California–Davis. Wewill probe the electrical properties of theinterface with impedance spectroscopyand cyclic voltammetry as a function oforganophosphate activity to evaluate theresponse of this sensor to analyteconcentration.

Samples of NQ- and BV-contain-ing siloxanes were synthesized and thecompounds characterized using cyclicvoltammetry and impedance spectros-copy. Although NQ/BV siloxanes werepreviously studied, this project is theirfirst known use as bioelectronic sensorplatforms.

We performed successfullaboratory experiments using NQ-siloxane deposited on glassy carbonelectrode surfaces with immobilizedOPH enzyme. Data supported thehypothesis tested in this study. Wetested this novel sensor with theorganophosphate nerve agentparaoxon (commercial pesticide), andit responded to five micromolarconcentration levels (about 1 ppm).This test result was garnered with littleoptimization of coating chemistry andshould be considered as an upperdetection limit of the sensor.

We immobilized the OPH enzymethat selectively cleaves paraoxon toform protons onto the carbon elec-trode surface with aminopropyltri-methoxysilane and glutaraldehydeprior to NQ-siloxane treatment. Weprepared the pH-sensitive NQ-siloxanefilm in aqueous solution and depositedit in approximately 25 minutes. Wemonitored the film growth electro-chemically and verified the presence ofOPH enzyme and NQ redox polymer inan independent experiment. Wemeasured the impedance of the carbonelectrode at 200 Hz to yield theparaoxon-dependent signal.

3537.120

Novel Biosensor FabricationTechniques

A. W. Flounders

Most chemical sensors consist of arecognition element that provides sensorspecificity and a transduction platformthat translates chemical presence into ameasurable signal. The term biosensordescribes a specific class of chemicalsensors that utilize a biological compo-nent (usually a protein such as anantibody or enzyme) as the chemical

recognition element. Biological compo-nents are paired with optical, piezoelec-tric, and microelectronic transductionplatforms.

To date, all biosensor fabricationhas been a two-step process. Automatedwafer-scale microelectronic fabricationis followed by dicing, packaging, andmanual chip-scale biochemical process-ing. Chip-scale biochemical processingis tedious, difficult to reproduce, andexpensive; it completely negates alleconomy-of-scale advantages of thesemiconductor manufacturing process.

Sandia is developing techniquesthat will enable wafer-scale processingof biochemical components. Recently,we demonstrated the ability to etchimmobilized protein layers with anoxygen plasma system. We will investi-gate the compatibility of other semicon-ductor processing tools with biochemicalcomponents. We will investigate the useof a photoresist priming oven fordeposition of organosilane monolayersin collaboration with University ofCalifornia, Berkeley (UC–Berkeley).This process would enable wafer-scalepreparation of surface layers ideallysuited for biochemical attachment. Thissurface will then be reacted with proteinsolutions applied from a spray-headphotoresist development station. Thecombination of vapor-phase monolayerformation followed by spray-dispenseprotein attachment and oxygen-plasmaetching may enable a fully integratablewafer-scale protein process flow.

Silicon (Si) substrates withthermally grown Si dioxide (SiO2) orthermally grown SiO2 plus low-pressure chemical vapor-deposited Sinitride (SiN) films were prepared at theUC–Berkeley Microfabrication Labora-tory. These films were then character-ized via ellipsometry, static contactangle, and electrolyte insulatorsemiconductor (EIS) impedancespectroscopy. We selectedaminopropyltriethoxysilane (APTS)and glycidoxypropyltriethoxysilane asbest candidates for silane surfacemodification and protein immobiliza-tion based on their solubility andflammability properties.


We identified an equipmentvendor with demonstration equipmentsuitable for the silane depositiontesting, and vapor-phase silanetreatment is under way.

Process compatibility also madeimpossible the use of the photoresistdispense station for application ofprotein solutions. Protein solutionstypically have a high sodium contentthat is a significant contaminant for Siprocessing.

Process compatibility issues notpreviously considered precluded theuse of already committed equipment.We prepared test substrates andidentified an alternate path for testingvapor-phase silane; testing is underway. We have not addressed theadditional component of spraydispense of proteins.

3537.140

Enhancing Multilevel LinearEquation Solvers UsingDomain DecompositionStrategies

J. R. Red-Horse

Sandia’s Accelerated StrategicComputing Initiative (ASCI)-fundedstructural dynamics finite-element (FE)software package, SALINAS, is anaccurate scalable linear equation solversuitable for a massively parallel (MP)computing platform. One approach thathas proven itself as a candidate is theso-called Finite Element Tearing andInterconnecting (FETI) solver conceivedand developed by researchers at theUniversity of Colorado (UC).

The FETI method is a domaindecomposition–based iterative solverthat has gained wide acceptance in thestructural analysis community forsolving large-scale FE problems of ASCItype. It is also an important componentof the SALINAS project. In collaborationwith UC’s FETI group, we will improvethe performance of the FETI solver for

the highly heterogeneous problems thatare often encountered at DOE.

• Partitioning a structure along itsmaterials boundaries. The moduledomain decomposition module,DOMDEC, of UC’s parallel FE structuralmechanics code, TOP/DOMDEC, hasbeen upgraded to understand theconcept of substructures (each ofthem corresponding to a differentmaterial zone), and to incorporate apartitioning scheme for the globalstructure on a substructure-by-substructure basis. We are currentlyvalidating this module.

• Constructing an edge–basedcoarse problem for improving the initialresidual. We developed a generaltheoretical framework for a FETImethod with enriched search direc-tions. This framework improved ourinsight into convergence issues andguided our construction of a new setof search directions for improving theinitial residual obtained for heteroge-neous problems. We programmed thisnew development into the existingFETI code, and will validate it andbenchmark it on SALINAS problems.

3537.130

Design for 100-Year-LifePrototype

T. W. Simmermacher

The great majority of designspecifications are based on meetingquantitative performance objectives(e.g., structural, electrical, thermal,radiation). Exhaustive studies and testsare typically performed to ensure thestated performance. Design optimizationfocuses on the ability of the product tomeet its prescribed function for thelowest acquisition cost. A new designapproach for increasing the long-termversatility of complex structures wasdeveloped recently at MIT. Titled“Design for 100-Year Life,” this noveldesign methodology (D100) directly

addresses life-cycle issues in an engi-neering design. Robust optimization ofcost and performance over extremeservice lives are key innovations in thisapproach. In collaboration with MIT,Sandia will (1) identify life-cycle designtrade-off criteria and (2) demonstratethe principles in the design of a proto-type structure. We will also review manyof the surety (reliability, safety, andsecurity) design approaches developedat Sandia, and compare and contrastthem with the D100 methodology. Thislooks at extremely long life cycles. Thisis a radical approach in that it involvesconsideration of new types of materials,construction techniques, embeddedsensors, and novel maintenance anddismantlement techniques.

Our success in nuclear weaponstockpile stewardship requires that weutilize new technology to evaluatesystem performance over extended lifecycles.

The three scenarios developed inthis research build on the developingcapabilities of Sandia’s StructuralHealth Monitoring program and theconcepts within the ArchitecturalSurety program, envisioning thecapability within a structure tomonitor and respond to the dynamicforces acting upon it. The scenariosexplored the potential time to applica-tion to construction, ranging from thenearer term for the componentperformance database to the long termfor the active control system. Webased the scenarios on a system–based approach to structural monitor-ing and active control versus thecomponent–based approach, wherethe latter approach defines a majorityof the current research and develop-ment activities. The complementarytechnologies within Sandia couldprovide other essential elements of thesystem, and their existence displaysthe potential opportunities forcreation of a larger system relating toother subsystems and controls withinthe home.


3537.150

In Situ and Ex SituInvestigations of LateralComposition

S. R. Lee

Spontaneous lateral compositionmodulation during short-periodsuperlattice (SPS) growth shows greatpotential as an alternative method toobtain quantum-size features in com-pound semiconductor alloys. Recentwork elucidated some of the growthconditions required for the spontaneousmodulation to occur, but the specificphysical mechanisms producing lateralcomposition modulation formation arenot fully understood.

In collaboration with researchersat the University of Michigan (UM), webegan the process of examining thegrowth surface of SPS structures that areknown to exhibit lateral compositionmodulation with in situ scanning-tunneling microscopy (STM). Oncesuccessful, this technique will provide afirst examination of the growing surfaceof the SPS.

We undertook further ex situstudies to examine the role of specificgrowth conditions on lateral composi-tion modulation formation using X-RayDiffraction Reciprocal Space Mapping(K-Mapping). These data resulted inimproved understanding of lateralcomposition modulation formation andaided in the development of thesematerials and structures for use in novel,low-dimensional device applications.

The scope of this project was toinvestigate some specific proposedformation mechanisms associated withlateral composition modulation inAlAs-InAs SPSs grown on (001) InP. Wesuccessfully characterized numeroussamples ex situ using x-ray reciprocalspace mapping to test the latesthypotheses concerning spontaneouslateral composition modulationformation. We made more limitedprogress during attempts to grow andimage modulated structures in situusing STM due to technical difficultieswith the STM instrumentation over thecourse of the project.

One major hypothesis examinedin the present ex situ experiments isthe idea that the lateral modulationperiod is controlled by the growthtemperature in a manner consistentwith a nucleation-and-growth/diffu-sion-length argument. X-ray diffractionreciprocal space maps of samplesgrown at temperatures ranging fromT=500°C to T=555°C show that lateralmodulation is present at all tempera-tures above T ~ 515°C. The periodicityof the modulation, however, remainsapproximately constant at a value of~ 25 nm for all temperatures examined.Therefore, we demonstrated that themodulation wavelength is, in fact, notcontrolled by surface-diffusion lengtheffects associated with the growthtemperature as previously believed.

A second hypothesis examinedin the ex situ experiments was the ideathat lateral composition modulationforms only for those structures where

the InAs-layer thickness in thesuperlattice exceeds some criticalthickness. This hypothesis came aboutas a result of previous experimentsthat strongly suggested that a mini-mum of 1.65 ml of InAs is required forAlAs-InAs SPS structures to developlateral composition modulation. X-rayreciprocal space maps of samplesgrown to explicitly test this hypothesisshow that in spite of sufficiently thickInAs layers, lateral compositionmodulation does not occur for SPSsamples where the average InAscomposition deviates by more than± 0.10 from the InP-lattice–matchedcomposition of 0.52 (these composi-tion bounds correspond to averagelattice mismatches of approximately± 0.7%). Thus, we demonstrated thatsimply exceeding an InAs critical layerthickness of 1.65 ml during SPS growthwill not alone lead to compositionalmodulation. An overriding parameterthat determines whether modulationoccurs is the average alloy composi-tion (or the associated average in-plane biaxial strain) of the SPS.

Publications

Refereed

Lee, S. R., J. M. Millunchick, R. D.Twesten, D. M. Follstaedt, J. L. Reno, S.P. Ahrehkiel, and A. G. Norman. 1998.“Reciprocal-Space Analysis of Compo-sitional Modulation in Short-PeriodSuperlattices Using Position-SensitiveX-Ray Detection.” J. Mater. Sci.: Mater.in Electron., submitted.


3537.160

Approximate Methods forComputing EigensolutionsUsing Automated MultilevelSubstructuring

J. R. Red-Horse

Recently, Sandia developed amethod for frequency response analysisof structures, known as Automated Multi-Level Substructuring (AMLS). Thismethod divides a large finite-element(FE) model automatically into thou-sands of substructures and transforms itso that response is represented in termsof the modal models for these substruc-tures. Apparently, AMLS is suitable forobtaining very accurate approximationsof global eigenpairs in a massivelyparallel (MP) environment with poten-tially large savings in computation timeand memory requirements. In collabora-tion with researchers at the University ofTexas–Austin, Sandia will develop aninitial interface between SALINAS andAMLS software and explore the feasi-bility of incorporating AMLS directly intothe SALINAS package. We will direct ourefforts toward coupling SALINAS-generated global mass and stiffnessmatrices from the serial version of thecode with the stand-alone AMLS codeand subsequently calculating approxi-mate global eigenvalue/eigenvectorpairs using it.

(1) We modified existing AMLSsoftware to enable the input of globalstructural matrices (those associatedwith the system stiffness and mass)from data files produced by Sandia’sASCI-funded structural dynamics FEcode, SALINAS. Now it is possible tocalculate approximate globaleigenpairs, in stand-alone fashion, forthe generalized eigenvalue problemassociated with those matrices.

(2) We performed an in-depthinvestigation into how SALINAShandles connectivity betweensubdomains in a parallel computingenvironment. The result was theproduction of a document that

describes how stiffness, mass, andconnectivity data associated withindividual subdomains can be writtento files by SALINAS, in either serial orparallel mode, so that AMLS softwarecan read these files, then process theFE model. This document will alsoprovide information on the feasibilityof incorporating AMLS as a solutionsequence that can be called fromwithin SALINAS itself.

3537.170

Living Tissue Engineering

S. N. Kempka

Living tissue engineering is thedevelopment of biological substitutesthrough the use of living cells andmaterials of synthetic or natural originand the fostering of tissue regenerationand/or remodeling to repair, replace, orenhance function. This area is beingdriven by patient needs since there areinsufficient native tissues to addressexisting needs. A new industry isemerging in this area. Techniques fortissue growth and preservation arepresently categorized as art forms; thatis, they are not determined using ascientific or engineering basis. Thiswork will apply the formidable capabili-ties of numerical analysis on thedevelopment of two important tissueengineering processes: bioreactor designand cryopreservation.

It is not known how to mostefficiently operate bioreactors, soSandia will explore the use of numericalsimulation to engineer the best operat-ing parameters. Another area to beexamined is cryopreservation, whichhas been successfully achieved forsingle cells, but attempts at cryo-preservation of multicellular massessuch as organs have not been successful.

The dominant physics thatdominate the bioreactor operation andcryopreservation are convection anddiffusion, for which numerical algo-rithms have been developed. In collabo-ration with researchers at the Georgia

Institute of Technology, we will use thesenumerical algorithms in conjunctionwith experiments to optimize bioreactoroperation and cryopreservation tech-niques for multicellular bodies.

Discussions with Georgia Techstaff and literature surveys in theseareas allowed us to focus on the cryo-preservation topic and eliminate the bio-reactor topic. The cryopreservation areawill focus on the inclusion of complexphase diagrams for the fluids involved,which describe highly complex behav-ior. This approach will benefit thecryopreservation project by providing amuch more detailed predictive capabil-ity than is presently used in the industry.

Our efforts resulted in thedecision to focus on cryopreservation.We based this decision on our findingsthat the phenomena associated withcryopreservation are more suitable tomake significant progress in a rela-tively short time, which is important indeveloping an initial program. Inparticular, our numerical simulationcapabilities in the cryopreservationarea are more mature than in thebioreactor area. This allows us tofocus on the implementation of highlyadvanced details of cryopreservationwithin a well-developed numericaltechnology.

We initiated an extensiveliterature review and developed aresearch plan. The literature reviewindicates that many of the data neededto describe cryopreservation areavailable, and that much of thecomplexity of cryopreservationphenomena has not yet been includedin numerical models. This situationprovides us with a unique opportunityto help remove the art associated withcryopreservation by using simulationto provide understanding of thecomplex phenomena associated withcryopreservation, and to use thisunderstanding to design new proce-dures to preserve multicellular massessuch as organs.

Our approach is to use adiffusion–based model in whichconvection is omitted and includecomplex phase phenomena.



Appendix A: Author Index


AAdams, D. P. 106, 192Adolf, D. B. 91Adriaans, M. J. 178Ahrens, E. H. 209Aidun, J. B. 90Alam, M. K. 148Alber, E. S. 90Allen, J. J. 102Allendorf, S. W. 92Allerman, A. A. 57, 58, 60, 62, 64, 65,

74, 76, 198, 202Alvin, K. F. 46, 94Ames, A. L. 114, 116Ammerlahn, H. R. 113Anderson, C. 68Anderson, D. J. 165Anderson, R. A. 26Anderson, R. J. 111, 118Anex, D. S. 19, 136, 148Arguello, J. G., Jr. 207Armstrong, R. C. 52, 130Asay, J. R. 224Asbill, R. E. 64Ashby, C. I. H. 60, 70, 105Asher, R. B. 210Ashley, C. S. 225Aselage, T. L. 190Attaway, S. W. 177Atwood, C. L. 98Aurand, J. F. 70, 206

BBaca, A. G. 73, 75, 156, 226Baer, M. R. 25, 90Baeza, A. R. 179Baker, A. B. 211Baldwin, J. M. 107Baldwin, M. D. 198Ballard, S. 212Bammann, D. J. 83, 86Barker, G. T. 212Barnaby, M. L. 38Bartel, L. C. 138, 212Bartelt, N. C. 22Bartholomew, J. W. 67Barton, D. L. 167Battaile, C. C. 42Baty, R. S. 44Baucom, K. C. 59Benavides, G. L. 102, 106, 192, 226Bennett, P. C. 171Benson, D. A. 66, 167

Berg, T. M. 194Bespalko, S. J. 123Bickel, D. L. 138Biefeld, R. M. 20, 62Bieg, L. F. 102Blair, D. S. 154Blake, R. J. 136Bliss, D. E. 192, 218Boehme, D. R. 216Boettcher, G. E. 182Bogdan, C. W. 165Bonivert, W. D. 216Borns, D. J. 150Boslough, M. B. 200Bouchard, A. M. 20Bow, W. J. 142Boyack, K. W. 53Boyle, T. J. 10Brady, P. V. 150Brainard, J. P. 183Braithwaite, J. W. 166Brandt, J. M. 124Brazee, J. L. 114Breiland, W. G. 70Brightwell, R. B. 50Brinker, C. J. 10, 135, 152, 186, 225Brockmann, J. E. 24, 165Brooks, J. A. 29Brown, K. H. 84Brown, R. G. 114, 116, 117Brunett, B. A. 222Buchheit, T. E. 42, 104Bujewski, G. E. 154Burchett, S. N. 66Burns, A. R. 15Burns, S. P. 34, 44Buss, R. J. 105Butler, M. A. 191Butler, P. C. 160, 168Byrne, R. H. 68

CCaffey, T. W. 212Calton, T. L. 114, 118Cameron, S. M. 192, 198, 199, 204, 218,

220, 226Campbell, A. N. 106Campbell, J. E. 162Campbell, P. L. 126Carichner, S. A. 172Carlson, D. C. 179Carlson, J. J. 103, 149, 180Carr, M. J. 26, 148

Carr, R. D. 50Casalnuovo, S. A. 14, 75, 77, 78Causey, R. A. 222Cesarano, J., III 25, 191, 218Chambers, R. S. 91Chambers, W. B. 172Chang, H. 198Chen, H. Y. 124, 130Chen, K. S. 93Chhabildas, L. C. 90Choquette, K. D. 57, 58, 60, 74, 76Chow, W. W. 10, 57, 65, 74Christenson, T. R. 68, 78, 97Christon, M. A. 44Chrzan, D. C. 12Chu, D. D. 142Claassen, J. P. 138Coats, R. S. 38Cochran, R. J. 34Cole, E. I., Jr. 167, 179Coleman, P. D. 206Collins, E. W. 106Coltrin, M. E. 59, 93Cordaro, J. T. 137Craft, R. L. 162Crawford, M. H. 10, 58, 73, 77, 171Crowder, S. V. 106Crowther, J. I., Jr. 210Cummings, E. B. 216Current, K. 61Curro, J. G. 41, 100, 148, 184

DDaniels, J. W. 136Day, D. M. 36, 223Dean, L. B. 126, 198De Boer, M. P. 21, 102Dec, J. E. 150Denison, G. J. 156De Sapio, V. 102, 107Desiena, T. H. 179Desjardin, P. E. 88Devine, K. D. 34, 36Diegert, C. F. 35Diegert, K. V. 46Dike, J. J. 82Dimos, D. B. 16Dison, H. L. 123Dodd, P. E. 70Dohner, J. L. 171Dohrmann, C. R. 84, 100Doran, L. M. 35Douglas, M. R. 201

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Doyle, B. L. 106Draelos, T. J. 130Draper, B. L. 62Dreeben, T. D. 89Drennen, T. E. 196Dron, S. B. 206Drummond, T. J. 59, 77Dugger, M. T. 12, 15Durant, J. L., Jr. 34Dykhuizen, R. C. 24

EEaton, W. P. 159Echekki, T. 89Eichel, P. H. 142Einfeld, W. 203Elbring, G. J. 138Emerson, J. A. 100Engi, D. 196Ensz, M. T. 25, 104Espinoza, J. 128Evans, G. H. 93Ewsuk, K. G. 207

FFalcone, P. K. 203Fan, D. 52Fang, H. E. 42Farino, A. J. 66Faulon, J. M. 43Feddema, J. T. 97, 103, 194Federico, P. J. 206Feibelman, P. J. 22, 184Fellerhoff, J. R. 138, 210Filter, W. F. 160Fisk, L. A. 52Fleetwood, D. M. 62Fleming, J. G. 66, 77Fleming, R. P. 179Flores, R. S. 70Floro, J. A. 22, 71Flounders, A. W. 142, 232Foiles, S. M. 86Follstaedt, D. M. 12, 58, 71, 77, 202Ford, D. M. 33Fossum, A. F. 207Fredrich, J. T. 84Friedman-Hill, E. J. 34Friedmann, T. A. 12, 188Friesen, J. A. 124, 125Frink, L. J. D. 36Fritz, I. J. 9Frye-Mason, G. C. 75, 135, 172Fuerschbach, P. W. 27Funkhouser, D. R. 162Fye, R. M. 41, 42, 52

GGarbin, H. D. 138Garcia, E. J. 61Gardner, T. J. 10, 152Garino, T. J. 68Garrett, S. E. 214Gee, J. M. 198, 202, 214Geib, K. M. 74, 76Gentile, A. C. 52Gentry, S. M. 136Gilliom, L. R. 194Gilmore, D. L. 24Gladwell, T. S. 111, 118Glass, S. J. 42Godfrey, A. W. 86Goeke, R. S. 183Goldsborough, S. S. 153Goldsmith, S. Y. 119, 194, 204Gonzales, R. A. 130Gourley, P. L. 9Griffith, M. L. 25, 98, 104Griffiths, S. K. 216Gritzo, L. A. 88, 92, 165Grotbeck, C. L. 179Guess, T. R. 91, 148Guthrie, S. E. 222

HHaaland, D. M. 148Hadley, G. R. 57, 65Hamilton, J. C. 17, 22, 43Hamilton, V. A. 130Hammons, B. E. 9, 74, 76Han, J. 10, 73, 77Harmony, D. W. 142Haroldsen, B. L. 203Harrington, J. J. 180Harris, D. L. 164, 196Hart, W. E. 48, 50, 108Harwell, L. D. 104Haynes, R. A. 38Hebner, G. A. 105Heffelfinger, G. S. 33Heinstein, M. W. 84Heller, E. J. 68, 75Helms, C. J. 58Henderson, C. L. 61Hendrickson, B. A. 53Henry, T. R. 123Hess, B. V. 216Heustess, J. E. 178Hicken, G. K. 107Hickerson, D. 114Hickox, C. E., Jr. 84Hiebert-Dodd, K. L. 196Hietala, S. L. 75

Hietala, V. M. 58, 75Hillaire, R. G. 107Hilton, N. R. 222Hinckley, M. K. 136Ho, C. K. 81Hobbs, D. J. 33Holcomb, D. J. 209Holland, K. G. 228Hollowell, J. A. 137Holm, E. A. 42, 86, 229Hopkins, P. L. 212Horn, K. M. 20, 59Horstemeyer, M. F. 43Hosking, F. M. 64Hough, P. D. 129Houston, J. E. 15, 17Hruby, J. M. 216Hu, T. C. 130Hughes, D. A. 83, 86Hughes, R. C. 10, 74, 142, 182Hunter, K. O. 48Hurd, A. J. 228Hurtado, J. E. 47Hutchinson, R. L. 119, 126Hwang, R. Q. 17, 28Hwang, Y. K. 123

IIngersoll, D. 198Irwin, L. W. 159, 160Istrail, S. 141, 218

JJackson, N. B. 196Jacobs, J. A. 199Jakowatz, C. V., Jr. 137Jamison, G. M. 26Janek, R. P. 142, 232Janssen, C. L. 40Jefferson, K. J. 179Jennison, D. R. 20, 26, 28Johnsen, H. A. 92Johnson, A. J. 106Johnson, D. K. 53Johnson, M. M. 113, 129Johnston, A. M. 130Jones, D. A. 50, 108Jones, E. D. 9, 10, 188Jortner, J. N. 125Jung, J. 100

KKasunic, K. J. 154Keck, J. D. 99Keefe, R. G. 212Kegelmeyer, W. P. 131



Kellogg, G. L. 22Kelly, M. J. 154Kemme, S. A. 154Kempka, S. N. 235Kent, M. S. 18Kern, J. P. 198Kerstein, A. R. 34, 89Key, S. W. 84Kiefer, M. L. 38King, C. 102King, D. B. 214King, R. K. 204Kjeldgaard, E. A. 50Klarer, P. R. 171Klein, P. A. 90Klem, J. F. 9, 59, 60, 71, 202Kliner, D. A. 208Knapp, J. A. 12, 21Knorovsky, G. A. 42Koch, M. W. 140Koller, M. H. 53Kottenstette, R. J. 75, 135Kozlowski, D. M. 102Kravitz, S. H. 58, 66, 78, 139, 142, 172Krumel, L. J. 136Kurtz, S. R. 9, 62, 72, 202

LLadd, M. D. 138Lafarge, R. A. 49, 123Laguna, G. A. 114Lanes, K. R. 179Larson, R. S. 93Larson, W. L. 160Lavigne, G. F. 192Lee, E. Y. 222Lee, S. R. 10, 71, 77, 202, 234Lemen, E. K. 113Leonard, C. M., Jr. 107Leung, K. 45Leung, V. J. 100Lewis, C. L. 49, 171Lewis, P. R. 135Lin, S. Y. 9, 72Lindgren, E. R. 36Link, H. E. 194Little, C. Q. 103, 114, 116, 149, 180Lo, C. S. 91Lockwood, S. J. 99Loehman, R. E. 185Lopez, E. P. 100Loubriel, G. M. 156, 199, 220Loy, D. A. 26, 148Lu, W. 82Ludowise, P. D. 92Lund, J. C. 222

Lyo, S. K. 9, 72

MMacCallum, D. O. 104Mah, B. A. 128Mansure, A. J. 212Mar, A. 65Marder, B. M. 210Marlman, K. S. 106Marozas, D. C. 164Martin, J. E. 26Martin, M. F. 106Martinez, L. G., Jr. 128Martinez, M. J. 212Martino, A. 19, 154Marx, K. D. 162Matalucci, R. V. 177Mayer, T. M. 14, 15, 21Mazarakis, M. G. 199McCarty, K. F. 12McDonald, M. J. 112McWhorter, P. J. 15Medlin, D. L. 12Meirans, L. 123Melius, C. F. 34, 40Meyers, C. E. 1Michalske, T. A. 15, 171Miles, P. C. 150Miller, J. C. 193Miller, J. E. 154, 196Miller, P. A. 105Miller, S. L. 15, 192Miodownik, M. A. 86Missert, N. A. 12, 189Mitchell, E. A. 114Mix, L. P., Jr. 38Modine, N. A. 45Moen, C. D. 51Moffat, H. K. 59Montague, S. 66Montoya, T. V. 99Moody, N. R. 17, 83Moore, R. H. 99Morales, A. M. 216Morgan, W. P. 214Mosher, D. A. 83Moya, M. M. 140Moyer, R. D. 178Murray, J. R. 62Myers, S. M., Jr. 73, 183

NNapolitano, L. M. 194Neilsen, M. K. 42Neiser, R. A., Jr. 24Nelson, C. L. 149, 180

Nelson, J. S. 20Nenoff, T. M. 147Nevers, J. A. 76Newman, G. A. 223Neyer, D. W. 136, 148Ngujo, M. A. 126Nicolette, V. F. 165Nilsen, V. 89Nilson, R. H. 216Noble, D. R. 84Nowlen, S. P. 165

OOberkampf, W. L. 46O’Connor, R. M. 84Olson, C. L. 199Osbourn, G. C. 20, 135, 171, 194Ottesen, D. K. 92

PPaez, T. L. 88Palmer, D. W. 124Paradiso, N. J., Jr. 153Parmeter, J. E. 227Pasik, M. F. 38Pate, R. C. 206Patterson, P. E. 206Paul, P. H. 201, 216Peace, G. L. 156Peña, E. A. 114Peña, J. G. 126Peng, L. W. 82Peters, R. R. 114, 118Peterson, D. W. 166Peterson, K. A. 159Phillips, C. A. 48, 50, 108Phillips, L. R. 194Pierson, L. G. 58, 126, 198Plantenga, T. D. 40, 113Plimpton, S. J. 17, 38, 40, 45, 50, 52Plymale, D. L. 102, 106Polosky, M. A. 97Prast, T. L. 216Provencio, P. N. 12, 26Pryor, R. J. 47, 164, 194

RRader, D. J. 139Rakestraw, D. J. 172Ray, L. P. 123Red-Horse, J. R. 88, 233, 235Redmond, J. M. 21Reed, K. W. 210Reedy, E. D., Jr. 18, 91, 100Reese, G. M. 36



Reeves, P. C. 212Renlund, A. M. 193Reno, J. L. 72, 75Renzi, R. F. 139Ricco, A. J. 14, 62, 67, 142Rieger, D. J. 105Riesen, R. E. 50Riley, D. J. 38, 206Rinehart, L. F. 206Rintoul, M. D. 42Rivord, G. E. 119Roach, D. W. 44Robertson, P. J. 58, 124, 126Robino, C. V. 66Robinson, A. C. 51Robinson, D. G. 88, 160, 166, 168, 211Rodacy, P. J. 191Rodgers, M. S. 61, 102Roe, D. C. 141, 203Romero, V. J. 88, 94Rondeau, D. M. 210Ross, J. R. 92Ruby, D. S. 105Ruffner, J. A. 16, 28, 214Rupley, F. M. 93Rutherford, B. M. 46, 94Ryba, G. N. 172

SSackos, J. T. 35Salazar, J. S. 140Salinger, A. G. 34, 36Salmi, A. J. 216Sands, D. N. 38Sarfaty, R. A. 119Sasaki, D. Y. 135Sault, A. G. 10, 28, 152, 196Saunders, R. S. 26, 148Schimmel, W. P. 210Schlienger, M. E. 98, 180Schmidt, R. C. 34, 89Schmitt, D. J. 25, 102, 111, 149Schmitt, R. G. 203Schneider, L. X. 210Schoeneman, J. L. 198Schoeniger, J. S. 136, 141, 142, 148, 225Schriner, H. K. 61Schubert, W. K. 16, 78, 226Schultz, P. A. 45Schunk, P. R. 51Schwank, J. R. 62Schwegel, J. 125Scofield, T. W. 99Scott, S. H. 148Seager, C. H. 73Sears, M. P. 20, 45, 50

Seidel, D. B. 38Seidl, E. T. 34Sellinger, A. 135Sexton, F. W. 70Shadid, J. N. 34, 51Shaddix, C. R. 92, 165Shaneyfelt, M. R. 62Shea, L. E. 58Sheaffer, D. A., Jr. 107Shelnutt, J. A. 26, 147, 154, 187, 231Shepodd, T. J. 19Shinn, N. D. 17Sholander, P. E. 128Shope, S. L. 199, 210Shul, R. J. 73, 77, 78Siebers, D. L. 150Siegel, M. D. 150Silva, B. L. 105Simmermacher, T. W. 230, 233Simmons, J. A. 72Simonson, K. M. 142Simonson, R. J. 225Singh, A. K. 225Sipola, D. L. 99Sleefe, G. E. 138Slutz, S. A. 224Small, D. E. 149, 180Smith, A. V. 60Smith, D. A. 136Smith, J. H. 16, 64, 192Smith, M. F. 24Smith, N. F. 159Smith, T. M. 34Smithberger, G. L. 179Smugeresky, J. E. 98Sniegowski, J. J. 15, 21, 61, 66Somerday, B. P. 222Sorensen, N. R. 166Spahn, O. B. 60, 64Spielman, R. B. 201, 224, 230Spires, S. V. 119, 194Spletzer, B. L. 47, 171, 194Spooner, J. T. 106Stallard, B. R. 136Stans, L. 130Stantz, K. M. 220Staple, B. D. 66Staton, A. W. 67Stechel, E. B. 45Stevens, M. J. 15, 18Stockman, H. W. 84Stone, C. M. 84Strickland, J. H. 88Sturtevant, J. E. 38Sullivan, C. T. 60, 198, 204Sullivan, J. P. 60, 188, 189

Swanson, B. E. 210Swartzentruber, B. S. 14, 22, 28Sweatt, W. C. 136, 154Sweet, J. N. 166Swiler, L. P. 88

TTan, M. X. 97, 139, 216Tanaka, T. J. 165Tangyunyong, P. 159, 167Tanner, D. M. 159Tappan, A. S. 193Tarbell, W. W. 204Tarman, T. D. 126, 130Thacher, P. D. 178Thomas, D. H. 136Thomas, E. V. 130Thomas, G. A. 203Thompson, A. P. 33Thompson, B. M. 162Thorne, L. R. 92Tigges, C. P. 59Tikare, V. 52, 104, 218Tolendino, L. F. 128Tong, C. H. 40, 51, 129Toth, R. P. 205Trahan, M. W. 220Trinkle, J. C. 114, 118Trott, W. M. 90Trucano, T. G. 94Tsang, R. P. 124Tsao, J. Y. 71Tuminaro, R. S. 36, 51Turman, B. N. 199Tuttle, B. A. 16, 99

UUlibarri, T. A. 148

VVan Blarigan, P. 153Vandernoot, V. A. 136Vandewart, R. L. 162Van Leeuwen, B. P. 128Van Swol, F. B. 41Vawter, G. A. 9, 60, 64, 65, 70Vedula, V. R. 42Venturini, E. L. 68Voigt, J. A. 99Volponi, J. V. 136Voth, T. E. 44

WWagner, J. F. 199Wagner, J. S. 48, 220



Walker, T. R. 107Walkup, J. W. 179Wally, K. 139, 142, 232Walsh, D. S. 70, 202Warren, M. E. 19, 58, 64, 76, 171Warren, W. L. 62Watterberg, P. A. 117Webb, S. W. 81Weber, T. M. 171Wehlburg, J. C. 179, 199Weinbrecht, E. A. 210Wellman, G. W. 42Wendt, J. R. 9, 64, 72Wessendorf, K. O. 78Wheeler, D. R. 26, 148Wilcoxon, J. P. 26Williams, A. B. 51Williams, J. S. 179Witkowski, W. R. 100Witzke, E. L. 126Wolfer, W. 171Womble, D. E. 44Wong, C. C. 171Woodworth, J. R. 70Wright. A. F. 10, 45, 73Wright, S. A. 172Wu, J. 153Wu, K. L. 153Wunsch, S. E. 89Wyckoff, P. S. 130Wylie, B. N. 53Wyss, G. D. 162

XXavier, P. G. 116, 123, 171

YYang, P. 105, 106Yarberry, V. R. 102, 192Yazzie, S. H. 160Yee, A. A. 138Yee, M. L. 138Yelton, W. G. 67Yocky, D. A. 140Yoshimura, A. S. 113Young, W. F. 119

ZZanini, D. V. 153Zavadil, K. R. 214Zhang, P. 150Zutavern, F. J. 65, 226



Appendix B: Project Number/Title Index

Page ProjectNumber Title Number



10 Catalytic Membrane Sensors 3502.030

9 Photonic Bandgap Structures asa Gateway to Nanophotonics 3502.040

10 Wide-Bandgap CompoundSemiconductors to Enable NovelSemiconductor Devices 3502.050

12 Ultra-Hard Multilayer Coatings 3502.080

14 Scanning Probe–Based Processesfor Nanometer-Scale DeviceFabrication 3502.090

15 Molecular-Scale Lubricants forMicromachine Applications 3502.110

16 Surface-Micromachined FlexuralPlate-Wave Device Integrated onSilicon 3502.120

17 Smart Interface Bonding Alloys(SIBA): Tailoring Thin-FilmMechanical Properties 3502.140

20 Recognizing Atoms in AtomicallyEngineered Nanostructures: AnInterdisciplinary Approach 3502.170

18 Molecular-to-Continuum FractureAnalysis of Thermoset Polymer/SolidInterfaces 3502.190

19 Monolithic Structures forNanoseparation 3502.210

21 Fundamental Aspects of Micro-machine Reliability 3502.220

24 Enabling Science and Technology forCold-Spray Direct Fabrication 3502.230

22 Atomic-Level Studies of Surfactant-Directed Materials Growth 3502.240

26 Intelligent Polymers for NanodevicePerformance Control 3502.250

25 Freeforming of Ceramics and Compo-sites from Colloidal Slurries 3502.260

26 Quantum Dot Arrays 3502.270

27 Laser-Assisted Arc Welding forAluminum Alloys 3502.280

28 Reactivity of Metal-Oxide Surfaces 3502.310

29 Exploiting LENS TechnologyThrough Novel Materials 3502.320

34 Parallel Quantum Chemistry forMaterial Aging and Synthesis 3504.010

34 Modeling Complex TurbulentChemically Reacting Flows onMassively Parallel Supercomputers 3504.020

35 Automated Geometric ModelBuilder Using Range Image SensorData 3504.050

36 A Massively Parallel SparseEigensolver for Structural DynamicsFinite Element 3504.060

36 Density-Functional Theory forClassical Fluids at ComplexInterfaces 3504.070

33 Gradient-Driven Diffusion of Multi-Atom Molecules Through Macro-molecules and Membranes 3504.090

38 Fast and Easy Parallel I/O forEfficient Scientific Computing 3504.120

38 Novel Load-Balancing for Scalable,Parallel Electromagnetic and PlasmaPhysics Simulation Software 3504.130

40 Parallel Computational ChemistryUsing Constraints 3504.140

40 Massively Parallel Ab InitioValidation for ASCI Materials Aging 3504.160

42 Computational Methods forCoupling Microstructural andMicromechanical MaterialsResponse Simulations 3504.170





44 An Investigation of Wavelet Bases forMultiscale, Grid–Based Simulation 3504.180

41 Integrated Quantum/ClassicalModeling of Hydrogenic Materials 3504.190

45 The Next Generation of TeraflopDensity-Functional ElectronicStructure Codes 3504.210

46 Methodology for CharacterizingModeling and DiscretizationUncertainties in ComputationalSimulation 3504.220

48 Global Optimization for EngineeringScience Problems 3504.230

49 Dynamic Simulation of MechanicalSystems with Intermittent Contacts 3504.240

43 From Atom-Picoseconds toCentimeter-Years in Simulation andExperiment 3504.250

47 Emergent Behavior of Large Swarmsof Intelligent Agents 3504.260

50 Parallel Combinatorial Optimizationfor Scheduling Problems 3504.270

50 Programming Paradigms forMassively Parallel Computers 3504.280

51 Multilevel Techniques forUnstructured Grid Problems onMassively Parallel Computers 3504.290

52 Scalable Tools for Massively ParallelDistributed Computing 3504.310

52 Massively Parallel Methods forSimulating the Phase Field Model 3504.320

53 Visual Explanation and Insight 3504.330

58 Wafer Fusion for Integration ofSemiconductor Materials and Devices 3506.110

58 Highly Parallel, Low-Power, PhotonicInterconnects for Inter-Board SignalDistribution 3506.120

59 Virtual Reactor for the SemiconductorManufacturing Plant of the Future 3506.140

60 Selective Oxidation Technology andIts Applications Toward Electronicand Optoelectronic Devices 3506.160

61 Agile Prototyping of Microelectro-mechanical Systems (MEMS) 3506.180

57 Advanced Concepts for High-PowerVCSELs and VCSEL Arrays 3506.190

62 Midwave-Infrared (2–6 µm) Emitter–Based Chemical Sensor Systems 3506.210

62 A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory 3506.230

64 Integration of Optoelectronics andMEMS by Free-Space Microoptics 3506.240

65 Advanced Laser Structures for Short-Pulsed Power in Active OpticalSensor Systems 3506.250

66 Metal Micro-Heat-Pipe Substrates forHigh-Power-Density Electronics 3506.260

68 Integration of MicrosensorTechnology into a Miniature RoboticVehicle 3506.270

66 Vacuum Encapsulation of MEMSStructures 3506.280

67 Massively Parallel Sensor Arrays forVolatile Organic Detection 3506.290

70 Agile Dry Etching of CompoundSemiconductors for Science–BasedManufacturing Using In Situ ProcessControl 3506.310

68 Precision-Formed Micromagnets 3506.320

70 Time-Resolved Ion-Beam–InducedCharge-Collection (TRIBICC) Imaging 3506.330

74 Composite-Resonator Surface-Emitting Lasers 3506.340





73 Role of Defects in III-Nitride–BasedElectronics 3506.350

74 Ultra–Low-Power Sensors forMicrotelemetry Systems 3506.360

72 Double Quantum-Well Long-Wavelength Optoelectronic Devices 3506.370

75 The Development of IntegratedChemical Microsensors in GaAs 3506.380

76 Monolithic Integration of VCSELs andDetectors for Microsystems 3506.410

77 AlGaN Materials Engineering forIntegrated Multifunction Systems 3506.420

71 Compliant Substrates for EpitaxialIntegration of Dissimilar Materials 3506.430

78 Post-Processed IntegratedMicrosystems 3506.440

83 Using Higher-Order Gradients toModeling Localization Phenomena 3508.040

81 Enhanced Vapor-Phase Diffusion inPorous Media 3508.060

82 Stress Evaluation and ModelValidation Using Laser Ultrasonics 3508.110

84 Altered Simulation Properties forTetrahedral Finite Elements for Usein Engineering Simulation 3508.120

84 Development, Implementation, andExperimental Validation of the LatticeBoltzmann Method for ModelingThree-Dimensional Complex Flows 3508.130

86 Capturing Recrystallization of Metalswith a Multiscale Material Model 3508.140

88 Nondeterministic Modeling inEngineering Science 3508.150

88 Lagrangian Modeling of RadiativeTransport 3508.160

89 High-Resolution Modeling ofMultiscale Transient Phenomena inTurbulent Boundary Layers 3508.170

90 Dispersive Measurements of Velocity in Heterogeneous Materials 3508.180

90 A Physically–Based ComputationalMethod for Predicting GeneralizedFracture 3508.190

92 Development of In Situ Diagnosticsfor Simultaneous Measurement ofTransient Gas Species and Soot inLarge Fires 3508.210

91 Micromechanical Failure Analysesfor Finite-Element Polymer Modeling 3508.220

94 Methodology Optimal Selection ofTest and Simulation Levels forProblems Involving ComputationalSimulation 3508.230

93 A Phenomenological Model forMulticomponent Transport withElectrochemical Reactions inConcentrated Solutions 3508.240

98 Laser-Spray Fabrication for Net-ShapeRapid Product Realization 3510.460

99 Solution Synthesis and Processing ofPZT Materials for Neutron-GeneratorApplications 3510.510

97 Ultra-Precise Assembly of Micro-electromechanical Systems (MEMS) 3510.540

100 Finite-Element Meshing Approachedas a Global Minimization Process 3510.570

102 Application of Parallel MechanismTechnology to Manufacturing 3510.580

100 Investigation of the Impact ofCleaning on Adhesive Bond and theProcess Implications 3510.590

102 Standard Cells for Microelectro-mechanical Systems (MEMS) 3510.610





104 Laser Wire Deposition for Fully DenseShapes 3510.620

105 High-Throughput Dry Processes forLarge-Area Devices 3510.630

106 Assuring High Reliability andProduction Readiness in Low-VolumeManufacturing 3510.640

103 Scripting for Video Inspection 3510.660

106 Advanced Machining Processes forMicrofabrication 3510.670

107 Fusion of Product and Process DataUsing Real-Time StreamingVisualization 3510.680

108 Advanced Production PlanningModels 3510.690

112 Automatic Generation of MultimediaDocumentation for AssemblyOperations 3511.010

113 Distributed Life-Cycle Models inEnterprise Simulations to AnswerSystem Questions 3511.020

114 Immersive CAD 3511.040

114 Automatic Planning of Life-CycleAssembly Processes 3511.050

116 Analysis of Very Large Assemblies 3511.070

111 Enabling Human Skills withCooperative Automation 3511.080

116 Cloud To CAD 3511.090

118 Ergonomics in Life-Cycle AssemblyProcesses 3511.110

117 Feature Reduction of Geometric SolidModels for Analysis Tools 3511.120

119 System Surety Life-Cycle Engineering 3511.130

123 Content–Based Search of GeometricDatabases 3512.160

124 Integrated Service Provisioning in an“IPv6 over ATM” Research Network 3512.170

125 Virtual Desktop Engineering with Integrated Multimedia Data 3512.180

123 Mission Surety for Large-Scale Real-Time Information Systems 3512.190

126 Scaled ATM End-to-End Encryption 3512.220

128 Network Surety Modeling forWireless ATM Networks 3512.230

130 Low-Power, Reduced-Computation,Public-Key Protocols 3512.240

126 Ten-to-One-Hundred-Gigabit/SecondNetwork Enabling R&D 3512.250

130 High-Performance CommodityInterconnects for Clustered Scientificand Engineering Computing 3512.260

131 AVATAR—Navigating and Mining inMassive Data 3512.270

129 Algorithm–Based Fault Tolerance onHeterogeneous Massively ParallelComputers 3512.280

136 Electrokinetic ImmunoaffinityChemical Sensors 3516.050

136 Information-Efficient SpectralImaging System (ISIS) 3516.060

137 Imaging of Moving Targets UsingSimultaneous Synthetic ApertureRadar (SAR) and Moving TargetIndicator (MTI) Radar 3516.070

135 Sampling and Sensing Systems forHigh-Priority Analytes 3516.080

138 Automated Vegetation HeightMeasurement for Automatic TerrainMapping 3516.090





138 Sparse Geophysical Networks forMonitoring Deep Targets 3516.110

139 Miniature Bioaerosol Concentrator 3516.120

140 Recognizing Partially ObscuredTargets by Combining Multiple DataSources Using Evidential Reasoning 3516.130

141 Computational Engineering of SensorMaterials and Integration with aNovel Biological Weapon DetectionSystem 3516.140

142 Biological Weapon Detector UsingBioaffinity Array Impedance Analysiswith Chemical Amplification Through Redox Recycling 3516.150

142 ATR / Exploitation Utilizing Ultra–High-Resolution, Complex SARImaging 3516.160

147 Designed Molecular RecognitionMaterials for Chiral Sensors,Separations, and Catalytic Materials 3518.030

148 Rapid Screening of Complex ChemicalSamples Via Capillary Array Analysis 3518.050

148 Designed Synthesis of ControlledDegradative Materials 3518.060

150 Mechanistic Models for RadionuclideDesorption from Soils 3518.070

150 Development of InnovativeCombustion Processes for a Direct-Injection Diesel Engine 3518.080

152 Hydrogen Production for Fuel Cellsby Selective Dehydrogenation ofAlkanes in Catalytic MembraneReactors 3518.090

153 Hybrid Vehicle Engine Development 3518.110

149 Adaptive 3-D Sensing 3518.120

154 Aqueous Organic Sensor 3518.130

154 Designed Ionophores for Liquid-Membrane Separation and Extraction of Metal Ions 3518.140

156 An Electromagnetic Imaging Systemfor Environmental SiteReconnaissance 3518.150

160 Reliability Degradation Due toStockpile Aging 3520.210

159 Integrated Approach to DevelopMicroelectromechanical (MEMS)Reliability Tools 3520.220

160 Precursors to Failure of Oxides andMetal Lines in CMOS Technology 3520.230

162 An Extensible Object-OrientedFramework for Risk and ReliabilityAnalysis 3520.240

162 Simulation/Optimization Tools forSystem Variability Analysis 3520.270

164 A Massively Parallel MicrosimulationModel of InfrastructureInterdependency 3520.280

166 Physical Models for Predicting theEffect of Atmospheric Corrosion onMicroelectronic Reliability 3520.290

167 Backside Localization of Open andShorted IC (Integrated Circuits)Interconnections 3520.310

165 Reliability Predictions for AdvancedElectronics in Smoke Environments 3520.320

168 Security of Bulk Power Systems 3520.330

171 Science on the Microdomain 3522.010

172 Autonomous MicroChemLaboratory (µChemLab) 3522.020

171 Cooperative, Distributed Sensing andAction Using Microminiature,Intelligent Agents 3522.030





177 Computational Methods forPredicting the Response of CriticalAs-Built Infrastructure to DynamicLoads (Architectural Surety) 3530.030

178 Background Radiation AnisotropyMeasurement Sensor (BRAMS) 3530.050

178 Exploitation of SatelliteCommunications Systems andNetworks for IntelligenceApplications 3530.090

179 Microcode Evaluation 3530.110

179 Real-Time Image Analysis Using Field-Programmable Gate Arrays 3530.120

180 Advanced 3-D Sensing andVisualization System for UnattendedMonitoring 3530.130

180 System-of-Labs Direct FabricationTechnology 3531.020

182 Poco Switch Tubes 3531.140

182 Chemiresistors Based on Metal-Loaded Polymers for Solvent SpillDetection 3531.150

183 Advanced Neutron-Tube Design andProducibility 3531.160

183 Surface Hardening by NanoparticlePrecipitation and Atomic Clusteringin Ni(Al,O) 3531.170

184 Dynamical Properties of Polymers:Computational Modeling 3531.180

188 Broadening Mechanism in 2-DExcitonic and Electron Gases 3531.190

184 Calculation and Interpretation of theEnergies that Underlie Transition-Metal Surface Structure 3531.210

185 Interfacial Reactions in CeramicSystems 3531.220

186 Direct Fabrication of MultifunctionalNanocomposites Via SupramolecularSelf-Assembly 3531.230

187 Biophotonic Materials for OpticalEncryption and Noncomputing 3531.240

188 Low-Stress Amorphous Diamond:A New Material for Sensors 3531.250

189 Nanoengineered Cu-Al Defects in Al:A Prototype System for Corrosion 3531.260

190 Novel Energy-Conversion Devices ofIcosahedral Borides 3531.270

191 Ion-Mobility Spectroscopy ofBiological Materials 3531.280

192 Visualization Tools for MEMS Designsin a Virtual 3-D World 3531.290

191 Direct Fabrication of Planar Solid-Oxide Fuel Cells 3531.310

192 Micromachining with Ultra-ShortPulsewidth Lasers 3531.320

193 Molecular Characterization ofEnergetic Material Initiation 3531.330

196 Chemical Feedstocks for the Future:Oxidative Dehydrogenation 3532.010

196 Global Approaches to InfrastructuralAnalysis (GAIA) 3532.030

194 Engineering Complex DistributedSystems 3532.070

198 Laser Communication Nanosatellites 3532.080

200 Collection and Data Synthesis ofAtmospheric Explosion Ground Truthfor Global Monitoring Systems 3532.090

201 Advanced Radiation Sources:Rayleigh-Taylor Mitigation ViaPerturbation Reduction 3532.110





201 Microfluidic Engineering 3532.120

199 Accelerator Technologies forEmerging Threats 3532.130

204 Technologies for System-LevelInnovations in Ballistic MissileDefense 3532.140

202 InGaAsN: A Novel Material for High-Efficiency Solar Cells and AdvancedPhotonic Devices 3532.150

203 Technologies for Countering C/BTerrorism 3532.160

205 Aerosol Stand-Off Detection Test-Bed 3532.170

206 Design and Optimization of High-Power Electromagnetic SourceSystems and Engagement Scenariosfor Achieving Functional Upset orDamage in Specific Target ElectronicSystems 3532.180

207 Real-Time Design of Improved PowderPressing Dies Using Finite-ElementMethod Modeling 3532.190

208 Development of Fiber-Laser–BasedLIF for Detection of SO2 3532.210

209 Penetration and Defeat of HardenedUnderground Facilities Using aMicrohole Drilling Robot 3532.220

210 IFSAR Tree Phenomenology andCoherence Normalization 3532.230

210 Electric Launcher for DefenseApplications 3532.240

212 SAM Telemetry for MeasurementsWhile Drilling 3533.050

214 Design-for-Manufacturability Appliedto Photovoltaic Modules 3533.070

212 Advanced Geosphere TransportSimulation 3533.160

214 Low-Work-Function ThermionicEmission Materials 3533.170

211 Power-Grid Reliability andRestructuring Policy Changes 3533.180

222 Low-Cost Cadmium Zinc TellurideRadiation Detectors Based onElectron-Transport-Only Designs 3534.020

216 LIGA Micromachining 3534.030

216 Applied Microfluidics Science 3534.040

218 Computational Simulations of Self-Assembling Macro-Systems by DirectFabrication of Microscopic StructuredMaterials 3535.130

218 Self-Stabilizing Optical Solitons andHigh-Intensity Laser Plasma Channelsfor Diffraction-Free Propagation andRobust Power Compression 3535.140

222 Novel Materials for HydrogenStorage 3535.150

220 Optical Communication System forRemote Monitoring and AdaptiveControl of Distributed GroundSensors Exhibiting CollectiveIntelligence 3535.160

223 Inversion of Passive ElectromagneticFields to Locate Weapons of MassDestruction 3535.170

224 Z-Pinch–Driven IsentropicCompression 3535.180

225 Covert, Distributed Biosensors forUXO/CW Based on AmplifiedImmunoassays Conducted in PorousInorganic Media 3535.190

226 Semiconductor Filament Lasers 3535.210

226 Development of Membrane DevicesUsing AlN and SiC Films 3537.010





227 Spectral Information Content in Ion-Mobility Spectra for Explosives,Interferants, and Other Negative-Ionizing Chemicals 3537.020

230 Magnetic Field Profile Measurementsin Wire-Array Z-Pinches by FaradayRotation 3537.030

228 Picosecond Particle VelocityMeasurements 3537.040

228 Particle-Level Modeling of Flows ofConcentrated Suspensions 3537.050

229 Efficient Processing of MaterialsMicrostructures with IntelligentFeature Extraction for QuantitativeStereology 3537.060

230 Nondestructive Evaluation of WindTurbine Blades 3537.070

231 Very Small Arrays: Designing Self-Assembled Systems of Light-Antennaeand Reaction Centers for ArtificialPhotosynthesis 3537.080

232 Enzyme-Mediated ElectrochemicalRedox Polymer Biosensor for V- andG-Type Chemical Weapons 3537.110

232 Novel Biosensor FabricationTechniques 3537.120

233 Design for 100-Year-Life Prototype 3537.130

233 Enhancing Multilevel Linear EquationSolvers Using Domain DecompositionStrategies 3537.140

234 In Situ and Ex Situ Investigations ofLateral Composition 3537.150

235 Approximate Methods for ComputingEigensolutions Using AutomatedMultilevel Substructuring 3537.160

235 Living Tissue Engineering 3537.170

Appendix C: Awards/Recognition List

Awards/Recognition Project Number Project Title


Peter Mark Award of the AmericanVacuum Society: Brian Swartzentruber

Discover Magazine Technology Award:Computer Hardware and Electronics (protonic memory)

1997 Industry Week Technology Award

New Mexico Inventor of the Year Award

1998 Award for Excellence: The GunterWittenberg Award for Best(Outstanding) Paper, on AssemblyAutomation, from the Literati Club

Paper selected for Best of the Best Papersession, Transportation Research Boardof the National Research Council, 1998Winter Meeting

1998 VeriBest Superior Systems Award,for most unusual circuit board design

Distinguished Lecturer for the AmericanVacuum Society

R&D 100 Award, R&D Magazine:COMRAD

Discover Magazine Award: protonicmemory

BES Materials Science Award:Microcavity Laser

3502.240

3506.230

3506.280

3511.050

3512.190

3512.220

3522.010

3534.020

3536.250

3539.220

Atomic-Level Studies of Surfactant-Directed Materials Growth

A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory

Vacuum Encapsulation of MEMSStructures

Automatic Planning of Life-CycleAssembly Processes

Mission Surety for Large-Scale Real-TimeInformation Systems

Scaled ATM End-to-End Encryption

Science on the Microdomain

Low-Cost Cadmium Zinc TellurideRadiation Detectors Based on Electron-Transport-Only Designs

Silicon–Based Nondestructive Read-outMemories

Biocavity Laser Microscopy/Spectros-copy of Cells



Performance Statistics (Number of)

Project Title Project # Ref

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* Permanent Staff Hired. Laboratories operate under manpower cap. Therre are no increases in

permanent staff.

** Goals Status

1 - Goals Met

2 - Goals Substantially Met

3 - Goals Partially Modified

4 - Goals Substantially Modified

5 - Goals Not Met

11- Project Terminated

***Hypothesis Status

6 - Hypothesis Proved

7 - Hypothesis Remains Unchanged

8 - Hypothesis Modified

9 - Hypothesis Redefined

10 - Hypothesis Disproved

11 - Project Terminated


Project Qualitative Assessment

Legend

Appendix D: Project Performance Measures



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Catalytic Membrane Sensors 3502.030 3 1 1 90% 2 7

Photonic Bandgap Structures as a Gateway to Nanophotonics 3502.040 2 2 100% 1 6

Wide-Bandgap Compound Semiconductors to Enable Novel Semiconductor Devices

3502.050 9 80% 2 6

Ultra-Hard Multilayer Coatings 3502.080 34 1 1 1 100% 2 8

Scanning Probe–Based Processes for Nanometer-Scale Device Fabrication 3502.090 2 1 50% 3 7

Molecular-Scale Lubricants for Micromachine Applications 3502.110 5 2 90% 2 6

Surface-Micromachined Flexural Plate-Wave Device Integrated on Silicon 3502.120 5 2 1 1 70% 2 7

Smart Interface Bonding Alloys (SIBA): Tailoring Thin-Film Mechanical Properties

3502.140 2 1 83% 1 7

Recognizing Atoms in Atomically Engineered Nanostructures: An Interdisciplinary Approach

3502.170 1 90% 2 6

Molecular-to-Continuum Fracture Analysis of Thermoset Polymer/Solid Interfaces

3502.190 1 4 2 1 70% 2 7

Monolithic Structures for Nanoseparation 3502.210 2 2 75% 3 8

Fundamental Aspects of Micromachine Reliability 3502.220 2 1 1 85% 2 7

Enabling Science and Technology for Cold-Spray Direct Fabrication 3502.230 2 1 1 100% 1 7

Atomic-Level Studies of Surfactant-Directed Materials Growth 3502.240 23 14 1 100% 2 7

Intelligent Polymers for Nanodevice Performance Control 3502.250 1 90% 2 7

Freeforming of Ceramics and Composites from Colloidal Slurries 3502.260 4 2 1 1 2 1 100% 1 7

Quantum Dot Arrays 3502.270 5 1 1 100% 1 6

Laser-Assisted Arc Welding for Aluminum Alloys 3502.280 1 1 2 100% 2 7

Reactivity of Metal Oxide Surfaces 3502.310 1 100% 1 7

Exploiting LENS Technology Through Novel Materials 3502.320 3 100% 1 7

Parallel Quantum Chemistry for Material Aging and Synthesis 3504.010 100% 1 6

Modeling Complex Turbulent Chemically Reacting Flows on Massively Parallel Supercomputers

3504.020 2 1 2 60% 3 7

Automated Geometric Model Builder Using Range-Image Sensor Data 3504.050 100% 1 7






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A Massively Parallel Sparse Eigensolver for Structural Dynamics Finite Element

3504.060 1 1 80% 2 6

Density Functional Theory for Classical Fluids at Complex Interfaces 3504.070 4 5 80% 2 6

Gradient-Driven Diffusion of Multi-Atom Molecules Through Macromolecules and Membranes

3504.090 5 7 1 3 80% 2 6

Fast and Easy Parallel I/O for Efficient Scientific Computing 3504.120 1 60% 3 7

Novel Load-Balancing for Scalable, Parallel Electromagnetic and Plasma Physics Simulation Software

3504.130 1 85% 2 7

Parallel Computational Chemistry Using Constraints 3504.140 3 5 100% 1 8

Massively Parallel Ab Initio Validation for ASCI Materials Aging 3504.160 100% 1 7

Computational Methods for Coupling Microstructural and Micromechanical Materials Response Simulations

3504.170 17 1 1 3 85% 1 7

An Investigation of Wavelet Bases for Multiscale, Grid–Based Simulation 3504.180 4 5 2 1 90% 2 6

Integrated Quantum/Classical Modeling of Hydrogenic Materials 3504.190 4 1 1 90% 2 7

The Next Generation of Teraflop Density Functional Electronic Structure Codes

3504.210 4 1 2 95% 2 7

Methodology for Characterizing Modeling and Discretization Uncertainties in Computational Simulation

3504.220 4 1 70% 3 7

Global Optimization for Engineering Science Problems 3504.230 8 14 1 1 90% 2 7

Dynamic Simulation of Mechanical Systems with Intermittent Contacts 3504.240 3 3 100% 1 7

From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment

3504.250 90% 1 7

Emergent Behavior of Large Swarms of Intelligent Agents 3504.260 1 100% 1 7

Parallel Combinatorial Optimization for Scheduling Problems 3504.270 1 82% 2 7

Programming Paradigms for Massively Parallel Computers 3504.280 80% 3 7

Multilevel Techniques for Unstructured Grid Problems on Massively Parallel Computers

3504.290 3 90% 2 7

Scalable Tools for Massively Parallel Distributed Computing 3504.310 2 1 1 100% 1 7

Massively Parallel Methods for Simulating the Phase Field Model 3504.320 1 100% 1 6




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Visual Explanation and Insight 3504.330 1 2 2 1 1 100% 1 7

Wafer Fusion for Integration of Semiconductor Materials and Devices 3506.110 3 1 80% 2 7

Highly Parallel, Low-Power, Photonic Interconnects for Inter-Board Signal Distribution

3506.120 1 85% 2 6

Virtual Reactor for the Semiconductor Manufacturing Plant of the Future 3506.140 1 100% 1 7

Selective Oxidation Technology and Its Applications Toward Electronic and Optoelectronic Devices

3506.160 16 4 80% 2 6

Agile Prototyping of Microelectromechanical Systems (MEMS) 3506.180 2 95% 1 6

Advanced Concepts for High-Power VCSELs and VCSEL Arrays 3506.190 10 1 1 100% 1 6

Midwave-Infrared (2-6 µm) Emitter–Based Chemical Sensor Systems 3506.210 2 1 1 80% 2 7

A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory 3506.230 7 2 1 3 100% 3 7

Integration of Optoelectronics and MEMS by Free-Space Microoptics 3506.240 2 1 1 1 1 75% 2 7

Advanced Laser Structures for Short-Pulsed Power in Active Optical Sensor Systems

3506.250 2 2 1 1 85% 2 8

Metal Micro-Heat-Pipe Substrates for High-Power-Density Electronics 3506.260 2 2 1 1 1 1 100% 1 6

Integration of Microsensor Technology into a Miniature Robotic Vehicle 3506.270 1 1 100% 1 7

Vacuum Encapsulation of MEMS Structures 3506.280 2 2 1 1 100% 1 7

Massively Parallel Sensor Arrays for Volatile Organic Detection 3506.290 1 1 80% 2 6

Agile Dry Etching of Compound Semiconductors for Science–Based Manufacturing Using In Situ Process Control

3506.310 100% 1 7

Precision-Formed Micromagnets 3506.320 1 1 2 80% 2 7

Time-Resolved Ion-Beam–Induced Charge-Collection (TRIBICC) Imaging 3506.330 1 1 90% 2 7

Composite-Resonator Surface-Emitting Lasers 3506.340 2 1 1 80% 2 7

Role of Defects in III-Nitride–Based Electronics 3506.350 9 90% 1 7

Ultra–Low-Power Sensors for Microtelemetry Systems 3506.360 1 1 1 1 1 90% 2 7

Double Quantum-Well Long-Wavelength Optoelectronic Devices 3506.370 3 1 1 1 2 1 60% 3 8




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The Development of Integrated Chemical Microsensors in GaAs 3506.380 1 1 100% 1 7

Monolithic Integrated of VCSELs and Detectors for Microsystems 3506.410 6 1 1 1 4 100% 1 7

AlGaN Materials Engineering for Integrated Multifunction Systems 3506.420 4 90% 2 6

Compliant Substrates for Epitaxial Integration of Dissimilar Materials 3506.430 50% 3 7

Post-Processed Integrated Microsystems 3506.440 1 35% 2 7

Using Higher-Order Gradients to Modeling Localization Phenomena 3508.040 6 1 90% 2 6

Enhanced Vapor-Phase Diffusion in Porous Media 3508.060 7 3 1 100% 1 6

Stress Evaluation and Model Validation Using Laser Ultrasonics 3508.110 6 1 2 95% 2 6

Altered Simulation Properties for Tetrahedral Finite Elements for Use in Engineering Simulation

3508.120 4 100% 2 6

Development, Implementation, and Experimental Validation of the Lattice Boltzmann Method for Modeling Three-Dimensional Complex Flows

3508.130 6 12 1 3 2 1 3 100% 1 6

Capturing Recrystallization of Metals with a Multiscale Material Model 3508.140 6 16 1 2 80% 2 7

Nondeterministic Modeling in Engineering Science 3508.150 2 90% 2 7

Lagrangian Modeling of Radiative Transport 3508.160 3 1 90% 2 7

High-Resolution Modeling of Multiscale Transient Phenomena in Turbulent Boundary Layers

3508.170 3 100% 1 7

Dispersive Measurements of Velocity in Heterogeneous Materials 3508.180 1 100% 1 6

A Physically–Based Computational Method for Predicting Generalized Fracture

3508.190 1 1 100% 2 7

Development of In Situ Diagnostics for Simultaneous Measurement of Transient Gas Species and Soot in Large Fires

3508.210 1 1 80% 2 7

Micromechanical Failure Analyses for Finite-Element Polymer Modeling 3508.220 95% 1 7

Methodology Optimal Selection of Test and Simulation Levels for Problems Involving Computational Simulation

3508.230 2 90% 2 7

A Phenomenological Model for Multicomponent Transport with Electrochemical Reactions in Concentrated Solutions

3508.240 85% 2 7




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Laser-Spray Fabrication for Net-Shape Rapid Product Realization 3510.460 5 2 4 1 2 1 1 3 95% 1 6

Solution Synthesis and Processing of PZT Materials for Neutron-Generator Applications

3510.510 1 1 1 1 1 100% 1 6

Ultra-Precise Assembly of Microelectromechanical Systems (MEMS) 3510.540 4 2 1 1 100% 1 6

Finite-Element Meshing Approached as a Global Minimization Process 3510.570 1 1 1 1 75% 3 8

Application of Parallel Mechanism Technology to Manufacturing 3510.580 2 5 4 2 1 95% 1 7

Investigation of the Impact of Cleaning on Adhesive Bond and the Process Implications

3510.590 2 2 5 1 1 100% 1 7

Standard Cells for Microelectromechanical Systems (MEMS) 3510.610 3 1 1 2 1 100% 2 7

Laser Wire Deposition for Fully Dense Shapes 3510.620 1 2 1 1 1 1 100% 2 9

High-Throughput Dry Processes for Large-Area Devices 3510.630 2 2 2 80% 3 7

Assuring High Reliability and Production Readiness in Low-Volume Manufacturing

3510.640 1 1 90% 2 6

Scripting for Video Inspection 3510.660 1 90% 4 8

Advanced Machining Processes for Microfabrication 3510.670 1 1 95% 2 7

Fusion of Product and Process Data Using Real-Time Streaming Visualization

3510.680 90% 2 7

Advanced Production Planning Models 3510.690 1 1 1 100% 1 7

Automatic Generation of Multimedia Documentation for Assembly Operations

3511.010 1 100% 2 6

Distributed Life-Cycle Models in Enterprise Simulations to Answer System Questions

3511.020 1 100% 1 6

Immersive CAD 3511.040 1 70% 2 6

Automatic Planning of Life-Cycle Assembly Processes 3511.050 3 8 1 1 1 100% 2 7

Analysis of Very Large Assemblies 3511.070 100% 1 7

Enabling Human Skills with Cooperative Automation 3511.080 100% 1 7

Cloud To CAD 3511.090 1 100% 1 7

Ergonomics in Life-Cycle Assembly Processes 3511.110 80% 3 7

Feature Reduction of Geometric Solid Models for Analysis Tools 3511.120 100% 2 7

System Surety Life-Cycle Engineering 3511.130 100% 2 7

Content–Based Search of Geometric Databases 3512.160 1 1 1 80% 2 7




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Integrated Service Provisioning in an “IPv6 over ATM” Research Network 3512.170 2 2 100% 4 6

Virtual Desktop Engineering with Integrated Multimedia Data 3512.180 2 80% 2 9

Mission Surety for Large-Scale Real-Time Information Systems 3512.190 2 1 1 1 100% 1 6

Scaled ATM End-to-End Encryption 3512.220 1 3 1 90% 2 7

Network Surety Modeling for Wireless ATM Networks 3512.230 1 3 95% 1 7

Low-Power, Reduced-Computation, Public-Key Protocols 3512.240 90% 2 7

Ten-to-One-Hundred-Gigabit/Second Network Enabling R&D 3512.250 1 1 100% 2 7

High-Performance Commodity Interconnects for Clustered Scientific and Engineering Computing

3512.260 1 100% 2 7

AVATAR—Navigating and Mining in Massive Data 3512.270 2 2 90% 1 7

Algorithm–Based Fault Tolerance on Heterogeneous Massively Parallel Computers

3512.280 90% 2 7

Electrokinetic Immunoaffinity Chemical Sensors 3516.050 1 1 1 1 85% 2 7

Information Efficient Spectral Imaging System (ISIS) 3516.060 4 1 1 3 1 100% 1 6

Imaging of Moving Targets Using Simultaneous Synthetic Aperture Radar (SAR) and Moving Target Indicator (MTI) Radar

3516.070 100% 1 7

Sampling and Sensing Systems for High-Priority Analytes 3516.080 2 1 1 80% 2 6

Automated Vegetation Height Measurement for Automatic Terrain Mapping

3516.090 1 1 50% 3 7

Sparse Geophysical Networks for Monitoring Deep Targets 3516.110 100% 1 7

Miniature Bioaerosol Concentrator 3516.120 1 90% 2 7

Recognizing Partially Obscured Targets by Combining Multiple Data Sources Using Evidential Reasoning

3516.130 3 95% 1 7

Computational Engineering of Sensor Materials and Integration with a Novel Biological Weapon Detection System

3516.140 1 1 1 100% 2 7

Biological Weapon Detector Using Bioaffinity Array Impedance Analysis with Chemical Amplification Through Redox Recycling

3516.150 1 95% 2 7

ATR / Exploitation Utilizing Ultra–High-Resolution, Complex SAR Imaging

3516.160 98% 2 7




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Designed Molecular Recognition Materials for Chiral Sensors, Separations, and Catalytic Materials

3518.030 9 1 2 1 1 95% 1 6

Rapid Screening of Complex Chemical Samples Via Capillary Array Analysis

3518.050 5 1 1 80% 2 6

Designed Synthesis of Controlled Degradative Materials 3518.060 100% 1 8

Mechanistic Models for Radionuclide Desorption from Soils 3518.070 6 1 100% 1 7

Development of Innovative Combustion Processes for a Direct-Injection Diesel Engine

3518.080 3 1 3 100% 1 7

Hydrogen Production for Fuel Cells by Selective Dehydrogenation of Alkanes in Catalytic Membrane Reactors

3518.090 3 1 1 50% 3 8

Hybrid Vehicle Engine Development 3518.110 4 1 1 1 3 1 90% 2 7

Adaptive 3-D Sensing 3518.120 5 100% 1 7

Aqueous Organic Sensor 3518.130 1 2 100% 1 7

Designed Ionophores for Liquid-Membrane Separation and Extraction of Metal Ions

3518.140 1 1 2 1 90% 2 6

An Electromagnetic Imaging System for Environmental Site Reconnaissance

3518.150 1 1 100% 1 7

Reliability Degradation Due to Stockpile Aging 3520.210 2 1 1 100% 1 6

Integrated Approach to Develop Microelectromechanical (MEMS) Reliability Tools

3520.220 1 6 1 78% 2 7

Precursors to Failure of Oxides and Metal Lines in CMOS Technology 3520.230 2 30% 3 9

An Extensible Object-Oriented Framework for Risk & Reliability Analysis 3520.240 2 1 75% 3 6

Simulation/Optimization Tools for System Variability Analysis 3520.270 75% 2 7

A Massively Parallel Microsimulation Model of Infrastructure Interdependency

3520.280 1 5 1 3 90% 1 7

Physical Models for Predicting the Effect of Atmospheric Corrosion on Microelectronic Reliability

3520.290 1 2 90% 2 7

Backside Localization of Open and Shorted IC (Integrated Circuits) Interconnections

3520.310 2 1 1 4 1 100% 1 6

Reliability Predictions for Advanced Electronics in Smoke Environments 3520.320 1 1 1 80% 3 8

Security of Bulk Power Systems 3520.330 50% 3 7

Science on the Microdomain 3522.010 7 2 1 1 90% 2 6

Autonomous MicroChem Laboratory (µChemLab) 3522.020 26 5 3 1 6 6 3 5 90% 2 7




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Cooperative, Distributed Sensing and Action Using Microminiature, Intelligent Agents

3522.030 5 100% 1 7

Computational Methods for Predicting the Response of Critical As-Built Infrastructure to Dynamic Loads (Architectural Surety)

3530.030 2 80% 2 7

Background Radiation Anisotropy Measurement Sensor (BRAMS) 3530.050 1 2 1 70% 2 8

Exploitation of Satellite Communications Systems and Networks for Intelligence Applications

3530.090 2 100% 1 6

Microcode Evaluation 3530.110 100% 2 7

Real-Time Image Analysis Using Field Programmable Gate Arrays 3530.120 1 1 1 1 80% 2 8

Advanced 3-D Sensing and Visualization System for Unattended Monitoring

3530.130 2 2 100% 1 6

System-of-Labs Direct Fabrication Technology 3531.020 4 1 2 75% 2 8

Poco Switch Tubes 3531.140 50% 2 6

Chemiresistors Based on Metal-Loaded Polymers for Solvent Spill Detection

3531.150 100% 1 7

Advanced Neutron-Tube Design and Producibility 3531.160 70% 3 7

Surface Hardening by Nanoparticle Precipitation and Atomic Clustering in Ni(Al,O)

3531.170 100% 1 6

Dynamical Properties of Polymers; Computational Modeling 3531.180 1 100% 1 7

Broadening Mechanism in 2-D Excitonic and Electron Gases 3531.190 100% 1 7

Calculation and Interpretation of the Energies That Underlie Transition-Metal Surface Structure

3531.210 1 1 1 100% 3 7

Interfacial Reactions in Ceramic Systems 3531.220 1 1 1 90% 2 7

Direct Fabrication of Multifunctional Nanocomposites Via Supramolecular Self-Assembly

3531.230 1 1 1 1 90% 1 6

Biophotonic Materials for Optical Encryption and Noncomputing 3531.240 1 3 1 1 90% 2 6

Low-Stress Amorphous Diamond: A New Material for Sensors 3531.250 1 1 100% 1 6

Nanoengineered Cu-Al Defects in Al: A Prototype System for Corrosion 3531.260 70% 2 7

Novel Energy Conversion Devices of Icosahedral Borides 3531.270 1 1 100% 1 7

Ion-Mobility Spectroscopy of Biological Materials 3531.280 1 1 100% 1 7




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Visualization Tools for MEMS Designs in a Virtual 3-D World 3531.290 1 1 100% 1 6

Direct Fabrication of Planar Solid Oxide Fuel Cells 3531.310 100% 1 6

Micromachining with Ultra-Short Pulsewidth Lasers 3531.320 1 90% 2 6

Molecular Characterization of Energetic Material Initiation 3531.330 1 1 100% 1 7

Chemical Feedstocks for the Future: Oxidative Dehydrogenation 3532.010 2 2 2 100% 1 7

Global Approaches to Infrastructural Analysis (GAIA) 3532.030 100% 1 7

Engineering Complex Distributed Systems 3532.070 10 4 3 1 80% 2 7

Laser Communication Nanosatellites 3532.080 1 1 6 3 90% 2 7

Collection and Data Synthesis of Atmospheric Explosion Ground Truth for Global Monitoring Systems

3532.090 1 80% 2 7

Advanced Radiation Sources: Rayleigh-Taylor Mitigation Via Perturbation Reduction

3532.110 1 1 90% 2 7

Microfluidic Engineering 3532.120 6 3 100% 1 6

Accelerator Technologies for Emerging Threats 3532.130 1 100% 1 7

Technologies for System-Level Innovations in Ballistic Missile Defense 3532.140 1 100% 2 7

InGaAsN: A Novel Material for High-Efficiency Solar Cells and Advanced Photonic Devices

3532.150 2 1 2 100% 1 7

Technologies for Countering C/B Terrorism 3532.160 2 100% 1 6

Aerosol Stand-Off Detection Test-Bed 3532.170 1 2 1 100% 1 7

Design and Optimization of High-Power Electromagnetic Source Systems and Engagement Scenarios for Achieving Functional Upset or Damage in Specific Target Electronic Systems

3532.180 1 100% 1 7

Real-Time Design of Improved Powder Pressing Dies Using Finite-Element Method Modeling

3532.190 1 1 80% 2 6

Development of Fiber-Laser-Based LIF for Detection of SO2 3532.210 1 75% 2 7

Penetration and Defeat of Hardened Underground Facilities Using a Microhole Drilling Robot

3532.220 1 100% 1 6

IFSAR Tree Phenomenology and Coherence Normalization 3532.230 1 1 50% 4 9

Electric Launcher for Defense Applications 3532.240 1 1 100% 1 6

SAM Telemetry for Measurements While Drilling 3533.050 1 3 1 100% 1 7




eree

d Pu

blic

atio

ns

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Oth

er R

epor

ts a

nd P

ublic

atio

ns

Pat

ent D

iscl

osur

es

Pat

ent A

pplic

atio

ns

Pat

ents

Cop

yrig

hts

Stu

dent

s

Pos

t-do

cs

Per

man

ent S

taff

Hir

ed*

Aw

ards

New

Non

-LD

RD

-Fun

ded

Proj

ects

†

% M

ilest

ones

Com

plet

ed

Goa

ls S

tatu

s**

Hyp

othe

ses

Stat

us**

*



Design-for-Manufacturability Applied to Photovoltaic Modules 3533.070 1 2 2 100% 1 6

Advanced Geosphere Transport Simulation 3533.160 2 2 1 1 90% 2 7

Low-Work-Function Thermionic Emission Materials 3533.170 1 2 75% 2 7

Power-Grid Reliability and Restructuring Policy Changes 3533.180 1 1 100% 1 6

Low-Cost Cadmium Zinc Telluride Radiation Detectors Based on Electron-Transport-Only Designs

3534.020 1 4 2 1 3 1 1 100% 1 6

LIGA Micromachining 3534.030 1 2 2 90% 1 6

Applied Microfluidics Science 3534.040 1 1 80% 2 7

Computational Simulations of Self-Assembling Macro-Systems by Direct Fabrication of Microscopic Structured Materials

3535.130 1 1 1 1 30% 1 9

Self-Stabilizing Optical Solitons and High-Intensity Laser Plasma Channels for Diffraction-Free Propagation and Robust Power Compression

3535.140 2 1 2 100% 2 6

Novel Materials for Hydrogen Storage 3535.150 1 50% 3 8

Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

3535.160 7 2 1 1 5 4 90% 1 6

Inversion of Passive Electromagnetic Fields to Locate Weapons of Mass Destruction

3535.170 1 1 2 1 90% 2 6

Z-Pinch-Driven Isentropic Compression 3535.180 1 75% 3 7

Covert, Distributed Biosensors for UXO/CW Based on Amplified Immunoassays Conducted in Porous Inorganic Media

3535.190 1 2 1 80% 2 7

Semiconductor Filament Lasers 3535.210 1 1 90% 1 6

Development of Membrane Devices Using AlN and SiC Films 3537.010 1 50% 3 7

Spectral Information Content in Ion-Mobility Spectra for Explosives, Interferants, and Other Negative-Ionizing Chemicals

3537.020 1 70% 3 7

Magnetic-Field Profile Measurements in Wire-Array Z-Pinches by Faraday Rotation

3537.030 1 100% 1 7

Picosecond Particle Velocity Measurements 3537.040 2 95% 1 6

Particle-Level Modeling of Flows of Concentrated Suspensions 3537.050 1 1 100% 1 6

Efficient Processing of Materials Microstructures with Intelligent Feature Extraction for Quantitative Stereology

3537.060 1 1 100% 1 7




eree

d Pu

blic

atio

ns

All

Oth

er R

epor

ts a

nd P

ublic

atio

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ent D

iscl

osur

es

Pat

ent A

pplic

atio

ns

Pat

ents

Cop

yrig

hts

Stu

dent

s

Pos

t-do

cs

Per

man

ent S

taff

Hir

ed*

Aw

ards

New

Non

-LD

RD

-Fun

ded

Proj

ects

†

% M

ilest

ones

Com

plet

ed

Goa

ls S

tatu

s**

Hyp

othe

ses

Stat

us**

*



Nondestructive Evaluation of Wind Turbine Blades 3537.070 1 1 1 100% 1 7

Very Small Arrays: Designing Self-Assembled Systems of Light-Antennae and Reaction Centers for Artificial Photosynthesis

3537.080 1 1 1 100% 1 6

Enzyme-Mediated Electrochemical Redox Polymer Biosensor for V- and G-Type Chemical Weapons

3537.110 1 100% 1 6

Novel Biosensor Fabrication Techniques 3537.120 75% 3 7

Design for 100-Year-Life Prototype 3537.130 1 100% 1 7

Enhancing Multilevel Linear Equation Solvers Using Domain Decomposition Strategies

3537.140 100% 1 6

In Situ and Ex Situ Investigations of Lateral Composition 3537.150 1 1 75% 3 8

Approximate Methods for Computing Eigensolutions Using Automated Multilevel Substructuring

3537.160 100% 1 6

Living Tissue Engineering 3537.170 100% 1 8

407 223 79 48 7 12 124 58 51 16 87

† Identification of new non-LDRD-funded projects is now completed in the fiscal year following the annual report.


Pg # Title Case Number Sci

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10 Catalytic Membrane Sensors3502.030

• •

9 Photonic Bandgap Structures as a Gateway to Nanophotonics 3502.040 • • • • • •

10Wide-Bandgap Compound Semiconductors to Enable Novel Semiconductor Devices

3502.050 • • • • • •

12 Ultra-Hard Multilayer Coatings 3502.080 • • • •

14 Scanning Probe–Based Processes for Nanometer-Scale Device Fabrication 3502.090 •

15 Molecular-Scale Lubricants for Micromachine Applications 3502.110 • •

16 Surface-Micromachined Flexural Plate-Wave Device Integrated on Silicon 3502.120 • • •

17Smart Interface Bonding Alloys (SIBA): Tailoring Thin-Film Mechanical Properties

3502.140 • •

20Recognizing Atoms in Atomically Engineered Nanostructures: An Interdisciplinary Approach

3502.170 • •

18Molecular-to-Continuum Fracture Analysis of Thermoset Polymer/Solid Interfaces

3502.190 • • • • • •

19 Monolithic Structures for Nanoseparation 3502.210 • • • • • • • • • • • • •

21 Fundamental Aspects of Micromachine Reliability 3502.220 • •

24 Enabling Science and Technology for Cold-Spray Direct Fabrication 3502.230 • • • • • • •

22 Atomic-Level Studies of Surfactant-Directed Materials Growth 3502.240 • •

26 Intelligent Polymers for Nanodevice Performance Control 3502.250 • •

25 Freeforming of Ceramics and Composites from Colloidal Slurries 3502.260 • • • •

Appendix E: DOE Critical Technologies



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26 Quantum Dot Arrays 3502.270 •

27 Laser-Assisted Arc Welding for Aluminum Alloys 3502.280 • • •

28 Reactivity of Metal Oxide Surfaces 3502.310 • •

29 Exploiting LENS Technology Through Novel Materials 3502.320 • • • •

34 Parallel Quantum Chemistry for Material Aging and Synthesis 3504.010 • • •

34Modeling Complex Turbulent Chemically Reacting Flows on Massively Parallel Supercomputers

3504.020 • • • • • • •

35 Automated Geometric Model Builder Using Range Image Sensor Data 3504.050 • • • • •

36A Massively Parallel Sparse Eigensolver for Structural Dynamics Finite Element

3504.060 • • • • • • •

36 Density-Functional Theory for Classical Fluids at Complex Interfaces 3504.070 • • •

33Gradient-Driven Diffusion of Multi-Atom Molecules Through Macromolecules and Membranes

3504.090 • • • • • •

38 Fast and Easy Parallel I/O for Efficient Scientific Computing 3504.120 • •

38Novel Load-Balancing for Scalable, Parallel Electromagnetic and Plasma Physics Simulation Software

3504.130 • • • • • •

40 Parallel Computational Chemistry Using Constraints 3504.140 • • •

40 Massively Parallel Ab Initio Validation for ASCI Materials Aging 3504.160 • • •

42Computational Methods for Coupling Microstructural and Micromechanical Materials Response Simulations

3504.170 • • • • •



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44 An Investigation of Wavelet Bases for Multiscale, Grid–Based Simulation 3504.180 • • • • •

41 Integrated Quantum/Classical Modeling of Hydrogenic Materials 3504.190 • • • •

45The Next Generation of Teraflop Density-Functional Electronic Structure Codes

3504.210 • •

46Methodology for Characterizing Modeling and Discretization Uncertainties in Computational Simulation

3504.220 • • • • • • •

48 Global Optimization for Engineering Science Problems 3504.230 • • • • • • • •

49 Dynamic Simulation of Mechanical Systems with Intermittent Contacts 3504.240 • • • • •

43 From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment 3504.250 • • • • • •

47 Emergent Behavior of Large Swarms of Intelligent Agents 3504.260 • • • •

50 Parallel Combinatorial Optimization for Scheduling Problems 3504.270 • •

50 Programming Paradigms for Massively Parallel Computers 3504.280 • • •

51Multilevel Techniques for Unstructured Grid Problems on Massively Parallel Computers

3504.290 • •

52 Scalable Tools for Massively Parallel Distributed Computing 3504.310 •

52 Massively Parallel Methods for Simulating the Phase Field Model 3504.320 • •

53 Visual Explanation and Insight 3504.330 • • •

58 Wafer Fusion for Integration of Semiconductor Materials and Devices 3506.110 • • • • •



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58Highly Parallel, Low-Power, Photonic Interconnects for Inter-Board Signal Distribution

3506.120 • • • •

59 Virtual Reactor for the Semiconductor Manufacturing Plant of the Future 3506.140 • • •

60Selective Oxidation Technology and Its Applications Toward Electronic and Optoelectronic Devices

3506.160 • • • • •

61 Agile Prototyping of Microelectromechanical Systems (MEMS) 3506.180 • • • • •

57 Advanced Concepts for High-Power VCSELs and VCSEL Arrays 3506.190 • • • • •

62 Midwave-Infrared (2–6 µm) Emitter–Based Chemical Sensor Systems 3506.210 • • • • •

62 A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory 3506.230 • •

64 Integration of Optoelectronics and MEMS by Free-Space Microoptics 3506.240 • • • • •

65Advanced Laser Structures for Short-Pulsed Power in Active Optical Sensor Systems

3506.250 • • •

66 Metal Micro-Heat-Pipe Substrates for High-Power-Density Electronics 3506.260 •

68 Integration of Microsensor Technology into a Miniature Robotic Vehicle 3506.270 • • • •

66 Vacuum Encapsulation of MEMS Structures 3506.280 • • • • • •

67 Massively Parallel Sensor Arrays for Volatile Organic Detection 3506.290 • •

70Agile Dry Etching of Compound Semiconductors for Science–Based Manufacturing Using In Situ Process Control

3506.310 • •

68 Precision-Formed Micromagnets 3506.320 • • • •



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70 Time-Resolved Ion-Beam–Induced Charge-Collection (TRIBICC) Imaging 3506.330 •

74 Composite-Resonator Surface-Emitting Lasers 3506.340 • •

73 Role of Defects in III-Nitride–Based Electronics 3506.350 • •

74 Ultra–Low-Power Sensors for Microtelemetry Systems 3506.360 • • • •

72 Double Quantum-Well Long-Wavelength Optoelectronic Devices 3506.370 • • • • •

75 The Development of Integrated Chemical Microsensors in GaAs 3506.380 • • •

76 Monolithic Integrated of VCSELs and Detectors for Microsystems 3506.410 • • • • •

77 AlGaN Materials Engineering for Integrated Multifunction Systems 3506.420 • • •

71 Compliant Substrates for Epitaxial Integration of Dissimilar Materials 3506.430 • • •

78 Post-Processed Integrated Microsystems 3506.440 • • • •

83 Using Higher-Order Gradients to Modeling Localization Phenomena 3508.040 • • • • • • • • •

81 Enhanced Vapor-Phase Diffusion in Porous Media 3508.060 • •

82 Stress Evaluation and Model Validation Using Laser Ultrasonics 3508.110 • • • • • • • • • •

84Altered Simulation Properties for Tetrahedral Finite Elements for Use in Engineering Simulation

3508.120 • • • • • • •

84Development, Implementation, and Experimental Validation of the Lattice Boltzmann Method for Modeling Three-Dimensional Complex Flows

3508.130 • • • • • •



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86 Capturing Recrystallization of Metals with a Multiscale Material Model 3508.140 • • • • • • • • • •

88 Nondeterministic Modeling in Engineering Science 3508.150 • • • • • • •

88 Lagrangian Modeling of Radiative Transport 3508.160 • • • •

89High-Resolution Modeling of Multiscale Transient Phenomena in Turbulent Boundary Layers

3508.170 • •

90 Dispersive Measurements of Velocity in Heterogeneous Materials 3508.180 • • • •

90A Physically–Based Computational Method for Predicting Generalized Fracture

3508.190 • • • •

92Development of In Situ Diagnostics for Simultaneous Measurement of Transient Gas Species and Soot in Large Fires

3508.210 • • • • •

91 Micromechanical Failure Analyses for Finite-Element Polymer Modeling 3508.220 • • • • • • •

94Methodology Optimal Selection of Test and Simulation Levels for Problems Involving Computational Simulation

3508.230 • • • • •

93A Phenomenological Model for Multicomponent Transport with Electrochemical Reactions in Concentrated Solutions

3508.240 • • • • • •

98 Laser-Spray Fabrication for Net-Shape Rapid Product Realization 3510.460 • • • • • • • • •

99Solution Synthesis and Processing of PZT Materials for Neutron-Generator Applications

3510.510 • •

97 Ultra-Precise Assembly of Microelectromechanical Systems (MEMS) 3510.540 • • •

100 Finite-Element Meshing Approached as a Global Minimization Process 3510.570 • • • • • • •



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102 Application of Parallel Mechanism Technology to Manufacturing 3510.580 • • • • • • •

100Investigation of the Impact of Cleaning on Adhesive Bond and the Process Implications

3510.590 • • • •

102 Standard Cells for Microelectromechanical Systems (MEMS) 3510.610 • •

104 Laser Wire Deposition for Fully Dense Shapes 3510.620 • • • •

105 High-Throughput Dry Processes for Large-Area Devices 3510.630 • • •

106Assuring High Reliability and Production Readiness in Low-Volume Manufacturing

3510.640 • • •

103 Scripting for Video Inspection 3510.660 • • •

106 Advanced Machining Processes for Microfabrication 3510.670 • • •

107Fusion of Product and Process Data Using Real-Time Streaming Visualization

3510.680 • • •

108 Advanced Production Planning Models 3510.690 • • • •

112Automatic Generation of Multimedia Documentation for Assembly Operations

3511.010 • • •

113Distributed Life-Cycle Models in Enterprise Simulations to Answer System Questions

3511.020 • • • •

114 Immersive CAD 3511.040 • • • •

114 Automatic Planning of Life-Cycle Assembly Processes 3511.050 • • • •

116 Analysis of Very Large Assemblies 3511.070 • • • • •

111 Enabling Human Skills with Cooperative Automation 3511.080 • • •



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116 Cloud To CAD 3511.090 • • • •

118 Ergonomics in Life-Cycle Assembly Processes 3511.110 • • • •

117 Feature Reduction of Geometric Solid Models for Analysis Tools 3511.120 • • • • • •

119 System Surety Life-Cycle Engineering 3511.130 • • • •

123 Content–Based Search of Geometric Databases 3512.160 • • • • •

124 Integrated Service Provisioning in an “IPv6 over ATM” Research Network 3512.170 •

125 Virtual Desktop Engineering with Integrated Multimedia Data 3512.180 • • • • •

123 Mission Surety for Large-Scale Real-Time Information Systems 3512.190 • • •

126 Scaled ATM End-to-End Encryption 3512.220 • •

128 Network Surety Modeling for Wireless ATM Networks 3512.230 • • •

130 Low-Power, Reduced-Computation, Public-Key Protocols 3512.240 • • •

126 Ten-to-One-Hundred-Gigabit/Second Network Enabling R&D 3512.250 • • • •

130High-Performance Commodity Interconnects for Clustered Scientific and Engineering Computing

3512.260 •

131 AVATAR — Navigating and Mining in Massive Data 3512.270 • • • • •

129Algorithm–Based Fault Tolerance on Heterogeneous Massively Parallel Computers

3512.280 • •

136 Electrokinetic Immunoaffinity Chemical Sensors 3516.050 • •



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136 Information-Efficient Spectral Imaging System (ISIS) 3516.060 • • • • •

137Imaging of Moving Targets Using Simultaneous Synthetic Aperture Radar (SAR) and Moving Target Indicator (MTI) Radar

3516.070 • • •

135 Sampling and Sensing Systems for High-Priority Analytes 3516.080 • • • •

138 Automated Vegetation Height Measurement for Automatic Terrain Mapping 3516.090 • •

138 Sparse Geophysical Networks for Monitoring Deep Targets 3516.110 • • •

139 Miniature Bioaerosol Concentrator 3516.120 • •

140Recognizing Partially Obscured Targets by Combining Multiple Data Sources Using Evidential Reasoning

3516.130 • •

141Computational Engineering of Sensor Materials and Integration with a Novel Biological Weapon Detection System

3516.140 • • •

142Biological Weapon Detector Using Bioaffinity Array Impedance Analysis with Chemical Amplification Through Redox Recycling

3516.150 • •

142 ATR/Exploitation Utilizing Ultra–High-Resolution, Complex SAR Imaging 3516.160 • • • •

147Designed Molecular Recognition Materials for Chiral Sensors, Separations, and Catalytic Materials

3518.030 • • •

148 Rapid Screening of Complex Chemical Samples Via Capillary Array Analysis 3518.050 • •

148 Designed Synthesis of Controlled Degradative Materials 3518.060 • •

150 Mechanistic Models for Radionuclide Desorption from Soils 3518.070 • •



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150Development of Innovative Combustion Processes for a Direct-Injection Diesel Engine

3518.080 •

152Hydrogen Production for Fuel Cells by Selective Dehydrogenation of Alkanes in Catalytic Membrane Reactors

3518.090 •

153 Hybrid Vehicle Engine Development 3518.110 •

149 Adaptive 3-D Sensing 3518.120 • • • • • • •

154 Aqueous Organic Sensor 3518.130 • • •

154Designed Ionophores for Liquid-Membrane Separation and Extraction of Metal Ions

3518.140 • • • •

156 An Electromagnetic Imaging System for Environmental Site Reconnaissance 3518.150 • • • • •

160 Reliability Degradation Due to Stockpile Aging 3520.210 • • • • • •

159Integrated Approach to Develop Microelectromechanical (MEMS) Reliability Tools

3520.220 • •

160 Precursors to Failure of Oxides and Metal Lines in CMOS Technology 3520.230 •

162 An Extensible Object-Oriented Framework for Risk and Reliability Analysis 3520.240 • •

162 Simulation/Optimization Tools for System Variability Analysis 3520.270 • • • •

164A Massively Parallel Microsimulation Model of Infrastructure Interdependency

3520.280 • • •

166Physical Models for Predicting the Effect of Atmospheric Corrosion on Microelectronic Reliability

3520.290 •

167Backside Localization of Open and Shorted IC (Integrated Circuit) Interconnections

3520.310 • •



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165 Reliability Predictions for Advanced Electronics in Smoke Environments 3520.320 • •

168 Security of Bulk Power Systems 3520.330 • • •

171 Science on the Microdomain 3522.010 • • • •

172 Autonomous MicroChem Laboratory (µChemLab) 3522.020 • • • • • • • • •

171Cooperative, Distributed Sensing and Action Using Microminiature, Intelligent Agents

3522.030 • • • •

177Computational Methods for Predicting the Response of Critical As-Built Infrastructure to Dynamic Loads (Architectural Surety)

3530.030 • • • •

178 Background Radiation Anisotropy Measurement Sensor (BRAMS) 3530.050 •

178Exploitation of Satellite Communications Systems and Networks for Intelligence Applications

3530.090 • • •

179 Microcode Evaluation 3530.110 • •

179 Real-Time Image Analysis Using Field-Programmable Gate Arrays 3530.120 • • •

180 Advanced 3-D Sensing and Visualization System for Unattended Monitoring 3530.130 • • • • • •

180 System-of-Labs Direct Fabrication Technology 3531.020 • • •

182 Poco Switch Tubes 3531.140 •

182 Chemiresistors Based on Metal-Loaded Polymers for Solvent Spill Detection 3531.150 • •

183 Advance Neutron-Tube Design and Producibility 3531.160 • •

183Surface Hardening by Nanoparticle Precipitation and Atomic Clustering in Ni(Al,O)

3531.170 • • • •



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184 Dynamical Properties of Polymers: Computational Modeling 3531.180 • • •

188 Broadening Mechanism in 2-D Excitonic and Electron Gases 3531.190 • • •

184Calculation and Interpretation of the Energies that Underlie Transition-Metal Surface Structure

3531.210 • •

185 Interfacial Reactions in Ceramic Systems 3531.220 • • •

186Direct Fabrication of Multifunctional Nanocomposites Via Supramolecular Self-Assembly

3531.230 • • •

187 Biophotonic Materials for Optical Encryption and Noncomputing 3531.240 • • • • • •

188 Low-Stress Amorphous Diamond: A New Material for Sensors 3531.250 • •

189 Nanoengineered Cu-Al Defects in Al: A Prototype System for Corrosion 3531.260 • •

190 Novel Energy-Conversion Devices of Icosahedral Borides 3531.270 •

191 Ion-Mobility Spectroscopy of Biological Materials 3531.280 • •

192 Visualization Tools for MEMs Designs in a Virtual 3-D World 3531.290 • • • • •

191 Direct Fabrication of Planar Solid-Oxide Fuel Cells 3531.310 • •

192 Micromachining with Ultra-Short Pulsewidth Lasers 3531.320 • • • •

193 Molecular Characterization of Energetic Material Initiation 3531.330 • • •

196 Chemical Feedstocks for the Future: Oxidative Dehydrogenation 3532.010 • •

196 Global Approaches to Infrastructural Analysis (GAIA) 3532.030 • • •



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194 Engineering Complex Distributed Systems 3532.070 • • • •

198 Laser Communication Nanosatellites 3532.080 • • • • • •

200Collection and Data Synthesis of Atmospheric Explosion Ground Truth for Global Monitoring Systems

3532.090 •

201Advanced Radiation Sources: Rayleigh-Taylor Mitigation Via Perturbation Reduction

3532.110 • • •

201 Microfluidic Engineering 3532.120 • •

199 Accelerator Technologies for Emerging Threats 3532.130 •

204 Technologies for System-Level Innovations in Ballistic Missile Defense 3532.140 • • • • • • • •

202InGaAsN: A Novel Material for High-Efficiency Solar Cells and Advanced Photonic Devices

3532.150 • •

203 Technologies for Countering C/B Terrorism 3532.160 • • •

205 Aerosol Stand-Off Detection Test-Bed 3532.170 •

206Design and Optimization of High-Power Electromagnetic Source Systems and Engagement Scenarios for Achieving Functional Upset or Damage in Specific Target Electronic Systems

3532.180 • • • • •

207Real-Time Design of Improved Powder Pressing Dies Using Finite-Element Method Modeling

3532.190 • • • •

208 Development of Fiber-Laser–Based LIF for Detection of SO2 3532.210 • • • • •

209Penetration and Defeat of Hardened Underground Facilities Using a Microhole Drilling Robot

3532.220 • • •

210 IFSAR Tree Phenomenology and Coherence Normalization 3532.230 • •



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Ass

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& E

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210 Electric Launcher for Defense Applications 3532.240 •

212 SAM Telemetry for Measurements While Drilling 3533.050 • •

214 Design-for-Manufacturability Applied to Photovoltaic Modules 3533.070 • • •

212 Advanced Geosphere Transport Simulation 3533.160 • •

214 Low-Work-Function Thermionic Emission Materials 3533.170 • •

211 Power-Grid Reliability and Restructuring Policy Changes 3533.180 • • •

222Low-Cost Cadmium Zinc Telluride Radiation Detectors Based on Electron-Transport-Only Designs

3534.020 • • • • •

216 LIGA Micromachining 3534.030 • •

216 Applied Microfluidics Science 3534.040 • • •

218Computational Simulations of Self-Assembling Macro-Systems by Direct Fabrication of Microscopic Structured Materials

3535.130 • • •

218Self-Stabilizing Optical Solitons and High-Intensity Laser Plasma Channels for Diffraction-Free Propagation and Robust Power Compression

3535.140 • • • •

222 Novel Materials for Hydrogen Storage 3535.150 • • • •

220Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

3535.160 • • • •

223Inversion of Passive Electromagnetic Fields to Locate Weapons of Mass Destruction

3535.170 • • • • • • •

224 Z-Pinch–Driven Isentropic Compression 3535.180 • • • •



ence

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ive

Cap

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& E

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Use

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& V

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Dyn

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225Covert, Distributed Biosensors for UXO/CW Based on Amplified Immunoassays Conducted in Porous Inorganic Media

3535.190 • •

226 Semiconductor Filament Lasers 3535.210 • • • • • • •

226 Development of Membrane Devices Using AlN and SiC Films 3537.010 • • •

227Spectral Information Content in Ion-Mobility Spectra for Explosives, Interferants, and Other Negative-Ionizing Chemicals

3537.020 • • •

230Magnetic-Field Profile Measurements in Wire-Array Z-Pinches by Faraday Rotation

3537.030 • •

228 Picosecond Particle Velocity Measurements 3537.040

228 Particle-Level Modeling of Flows of Concentrated Suspensions 3537.050 • • • •

229Efficient Processing of Materials Microstructures with Intelligent Feature Extraction for Quantitative Stereology

3537.060 • • •

230 Nondestructive Evaluation of Wind Turbine Blades 3537.070 • •

231Very Small Arrays: Designing Self-Assembled Systems of Light-Antennae and Reaction Centers for Artificial Photosynthesis

3537.080 • • • •

232Enzyme-Mediated Electrochemical Redox Polymer Biosensor for V- and G-Type Chemical Weapons

3537.110 • • •

232 Novel Biosensor Fabrication Techniques 3537.120 • •

233 Design for 100-Year-Life Prototype 3537.130 • • • • •

233Enhancing Multilevel Linear Equation Solvers Using Domain Decomposition Strategies

3537.140 • • •



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ive

Cap

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& E

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eeri

ng

Use

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& V

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icat

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atio

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Ver

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n

Dyn

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Tes

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in S

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234 In Situ and Ex Situ Investigations of Lateral Composition 3537.150 • •

235Approximate Methods for Computing Eigensolutions Using Automated Multilevel Substructuring

3537.160 • • •

235 Living Tissue Engineering 3537.170 • •


Pg # Title Case Number Was

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Ene

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Eff

icie

ncy

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ewab

le E

nerg

y

ES&

H

Env

iron

men

tal R

esto

ratio

n

Fos

sil E

nerg

y

Rad

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tive-

Was

te M

anag

emen

t

Eco

nom

ic I

mpa

ct

Ene

rgy

Res

earc

h

Int

ellig

ence

& N

atio

nal S

ecur

ity

Nuc

lear

Ene

rgy

Sci

ence

Edu

catio

n &

Tec

hnic

al I

nfor

mat

ion

Def

ense

Pro

gram

s

Dep

artm

ent o

f D

efen

se (

DoD

)

Oth

er F

eder

al A

genc

ies*

Oth

er (

Indu

stry

, Con

sort

ia,…

)**

Oth

er F

eder

al A

genc

ies*

Oth

er

(Ind

ustr

y, C

onso

rtia

…)*

*

10 Catalytic Membrane Sensors 3502.030 • •

9 Photonic Bandgap Structures as a Gateway to Nanophotonics 3502.040 • • • •


3502.050 • • •

12 Ultra-Hard Multilayer Coatings 3502.080 • • • • • • •

14Scanning Probe–Based Processes for Nanometer-Scale Device Fabrication

3502.090 • • •

15 Molecular-Scale Lubricants for Micromachine Applications 3502.110 • •

16Surface-Micromachined Flexural Plate-Wave Device Integrated on Silicon

3502.120 • • • • •


3502.140 •


3502.170 •


3502.190 • • • Industry

19 Monolithic Structures for Nanoseparation 3502.210 • • • • • • • • • • • • • • • • *EPA, NIH **auto, steel,

glass, chemical, etc.

21 Fundamental Aspects of Micromachine Reliability 3502.220 • • • •

24Enabling Science and Technology for Cold-Spray Direct Fabrication

3502.230 • • • • • • • • •*Department of

Commerce, NIST **U.S.

auto industry and other

U.S. industries

22 Atomic-Level Studies of Surfactant-Directed Materials Growth 3502.240 • •

26 Intelligent Polymers for Nanodevice Performance Control 3502.250 • •

Appendix F: Major National Programs



te M

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Eff

icie

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H

Env

iron

men

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esto

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n

Fos

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y

Rad

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rgy

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Int

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& N

atio

nal S

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ity

Nuc

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Ene

rgy

Sci

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n &

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al I

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ion

Def

ense

Pro

gram

s

Dep

artm

ent o

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25Freeforming of Ceramics and Composites from Colloidal Slurries

3502.260 • • •

26 Quantum Dot Arrays 3502.270 • •

27 Laser-Assisted Arc Welding for Aluminum Alloys 3502.280 • • • • • • • **Industry

28 Reactivity of Metal-Oxide Surfaces 3502.310 • • •

29 Exploiting LENS Technology Through Novel Materials 3502.320 • • • • • • • *DOC **Industry

34 Parallel Quantum Chemistry for Material Aging and Synthesis 3504.010 • • •


3504.020 • • • • • • •

35Automated Geometric Model Builder Using Range Image Sensor Data

3504.050 • • • • •


3504.060 • • • • • • • • •

36Density-Functional Theory for Classical Fluids at Complex Interfaces

3504.070 • • •


3504.090 • • • • • • •

38 Fast and Easy Parallel I/O for Efficient Scientific Computing 3504.120 • • • •


3504.130 • • • • • • **Microelectronics

40 Parallel Computational Chemistry Using Constraints 3504.140 • • •



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40Massively Parallel Ab Initio Validation for ASCI Materials Aging

3504.160 • •


3504.170 • • •

44An Investigation of Wavelet Bases for Multiscale, Grid–Based Simulation

3504.180 • • • • • •

41Integrated Quantum/Classical Modeling of Hydrogenic Materials

3504.190 • • • • •


3504.210 • • •


3504.220 • • • • • • • • •

48 Global Optimization for Engineering Science Problems 3504.230 • • • • • • •

49Dynamic Simulation of Mechanical Systems with Intermittent Contacts

3504.240 • • •

43From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment

3504.250 • • • • •

47 Emergent Behavior of Large Swarms of Intelligent Agents 3504.260 • • • •

50 Parallel Combinatorial Optimization for Scheduling Problems 3504.270 •

50 Programming Paradigms for Massively Parallel Computers 3504.280 • • •


3504.290 •

52 Scalable Tools for Massively Parallel Distributed Computing 3504.310 • •

52Massively Parallel Methods for Simulating the Phase Field Model

3504.320 • • • •



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53 Visual Explanation and Insight 3504.330 • • • • •

58Wafer Fusion for Integration of Semiconductor Materials and Devices

3506.110 • • • •


3506.120 • • • *NSA, CIA

59Virtual Reactor for the Semiconductor Manufacturing Plant of the Future

3506.140 • • •


3506.160 • • • •

61 Agile Prototyping of Microelectromechanical Systems (MEMS) 3506.180 • • • • **Aerospace

57Advanced Concepts for High-Power VCSELs and VCSEL Arrays

3506.190 • • • •

62Midwave-Infrared (2–6 µm) Emitter–Based Chemical Sensor Systems

3506.210 • • • •

62A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory

3506.230 • • • • • *DOE **Industry

64Integration of Optoelectronics and MEMS by Free-Space Microoptics

3506.240 • • •


3506.250 • • • • • 3-letter

66Metal Micro-Heat-Pipe Substrates for High-Power-Density Electronics

3506.260 • • • • **Electronics

manufacturers

68Integration of Microsensor Technology into a Miniature Robotic Vehicle

3506.270 • •

66 Vacuum Encapsulation of MEMS Structures 3506.280 • • • • •**Analog Devices, Inc.,

Rockwell International,

Texas Instruments

67 Massively Parallel Sensor Arrays for Volatile Organic Detection 3506.290 • • •



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3506.310 • • •

68 Precision-Formed Micromagnets 3506.320 • • • • •

70Time-Resolved Ion-Beam–Induced Charge-Collection (TRIBICC) Imaging

3506.330 • • • • • *NSA, Air Force, NASA

**IC industries

74 Composite-Resonator Surface-Emitting Lasers 3506.340 • • •

73 Role of Defects in III-Nitride–Based Electronics 3506.350 • • •

74 Ultra–Low-Power Sensors for Microtelemetry Systems 3506.360 • • • • • •

72Double Quantum-Well Long-Wavelength Optoelectronic Devices

3506.370 • • • •

75 The Development of Integrated Chemical Microsensors in GaAs 3506.380 • • • *EPA

76Monolithic Integration of VCSELs and Detectors for Microsystems

3506.410 • • • •

77AlGaN Materials Engineering for Integrated Multifunction Systems

3506.420 • • • •

71Compliant Substrates for Epitaxial Integration of Dissimilar Materials

3506.430 • • • •

78 Post-Processed Integrated Microsystems 3506.440 • • • • 3-letter

83Using Higher-Order Gradients to Modeling Localization Phenomena

3508.040 • • • • • • **NCMS, USCAR

81 Enhanced Vapor-Phase Diffusion in Porous Media 3508.060 • • • • •

82 Stress Evaluation and Model Validation Using Laser Ultrasonics 3508.110 • • • • • • • • • • •*NRC, EPA **Auto,

glass, steel, energy, &

chemical industries



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3508.120 • • • • • • • • • **Auto, aerospace

industries

84Development, Implementation, and Experimental Validation of the Lattice Boltzmann Method for Modeling Three-Dimensional Complex Flows

3508.130 • • • • • • • • • • *NASA

86Capturing Recrystallization of Metals with a Multiscale Material Model

3508.140 • • • • • •**NCMS, USCAR,

aluminum & steel

suppliers

88 Nondeterministic Modeling in Engineering Science 3508.150 • • • • • • • • •

88 Lagrangian Modeling of Radiative Transport 3508.160 • • • • *FAA, NASA **Insurance


3508.170 • • • • • •

90Dispersive Measurements of Velocity in Heterogeneous Materials

3508.180 • • • • • *NASA


3508.190 • • • • • • • •


3508.210 • • • • • • *DOC/NIST, EPA

91Micromechanical Failure Analyses for Finite-Element Polymer Modeling

3508.220 • • • • • •*Department of

Commerce **Aerospace,

automotive, coatings


3508.230 • • • • •



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93A Phenomenological Model for Multicomponent Transport with Electrochemical Reactions in Concentrated Solutions

3508.240 • • • • • •*DOE **Polymeric thin-

film coating &

semiconductor

manufacturing industries

98Laser-Spray Fabrication for Net-Shape Rapid Product Realization

3510.460 • • • • • • **LENS Consortium


3510.510 •

97Ultra-Precise Assembly of Microelectromechanical Systems (MEMS)

3510.540 • **Industry

100Finite-Element Meshing Approached as a Global Minimization Process

3510.570 • • • • • • •

102Application of Parallel Mechanism Technology to Manufacturing

3510.580 • • • • • • *NIST **Hexapod Users

Group


3510.590 • • • • • • **NCMS, Sematech,

industry

102 Standard Cells for Microelectromechanical Systems (MEMS) 3510.610 • • • • **Aerospace

104 Laser Wire Deposition for Fully Dense Shapes 3510.620 • • • •

105 High-Throughput Dry Processes for Large-Area Devices 3510.630 • • • • **Semiconductor industry


3510.640 • • •

103 Scripting for Video Inspection 3510.660 • •

106 Advanced Machining Processes for Microfabrication 3510.670 • • • • •


3510.680 •

108 Advanced Production Planning Models 3510.690 • •



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3511.010 • • • • **Consortia


3511.020 • • •

114 Immersive CAD 3511.040 • • •

114 Automatic Planning of Life-Cycle Assembly Processes 3511.050 • • • **Consortia

116 Analysis of Very Large Assemblies 3511.070 • • • • **Consortia

111 Enabling Human Skills with Cooperative Automation 3511.080 • • • •

116 Cloud To CAD 3511.090 • • • •

118 Ergonomics in Life-Cycle Assembly Processes 3511.110 • • • • **Consortia

117Feature Reduction of Geometric Solid Models for Analysis Tools

3511.120 • • • • **Consortia

119 System Surety Life-Cycle Engineering 3511.130 • • • • • • • *DoT **FSTC

123 Content–Based Search of Geometric Databases 3512.160 • • • • • **Industry

124Integrated Service Provisioning in an “IPv6 over ATM” Research Network

3512.170 • • • **Communications &

Networking

125 Virtual Desktop Engineering with Integrated Multimedia Data 3512.180 •

123 Mission Surety for Large-Scale Real-Time Information Systems 3512.190 • • • •

126 Scaled ATM End-to-End Encryption 3512.220 • •

128 Network Surety Modeling for Wireless ATM Networks 3512.230 • • • • **Telecom Standards



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130 Low-Power, Reduced-Computation, Public-Key Protocols 3512.240 • • • • • **IAGA, Cellular

Telephony

126 Ten-to-One-Hundred-Gigabit/Second Network Enabling R&D 3512.250 • • • •**Telecommunications &

computer networking

companies


3512.260 •

131 AVATAR — Navigating and Mining in Massive Data 3512.270 • • • •


3512.280 • •

136 Electrokinetic Immunoaffinity Chemical Sensors 3516.050 • • • •

136 Information-Efficient Spectral Imaging System (ISIS) 3516.060 • • • • • • •


3516.070 • • •

135 Sampling and Sensing Systems for High-Priority Analytes 3516.080 • • • • • • • • • **CIA, FBI

138Automated Vegetation Height Measurement for Automatic Terrain Mapping

3516.090 • • • **NIMA, DOE-NN, Army

Tec

138 Sparse Geophysical Networks for Monitoring Deep Targets 3516.110 • •

139 Miniature Bioaerosol Concentrator 3516.120 • • •


3516.130 • •


3516.140 • •



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3516.150 • • • • •

142ATR/Exploitation Utilizing Ultra–High-Resolution, Complex SAR Imaging

3516.160 • •


3518.030 • • • **Chemical &

pharmaceutical industries

148Rapid Screening of Complex Chemical Samples Via Capillary Array Analysis

3518.050 • • • • *EPA

148 Designed Synthesis of Controlled Degradative Materials 3518.060 • •

150 Mechanistic Models for Radionuclide Desorption from Soils 3518.070 • • • • •


3518.080 • • • **Diesel engine

manufacturers


3518.090 • • • • •

153 Hybrid Vehicle Engine Development 3518.110 • • • •

149 Adaptive 3-D Sensing 3518.120 • • • • • •

154 Aqueous Organic Sensor 3518.130 • • •


3518.140 • • • • • • • • • • • • *EPA **Industry

156An Electromagnetic Imaging System for Environmental Site Reconnaissance

3518.150 • • • • • *CIA

160 Reliability Degradation Due to Stockpile Aging 3520.210 • • • **Industry



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3520.220 • •

160Precursors to Failure of Oxides and Metal Lines in CMOS Technology

3520.230 • •

162An Extensible Object-Oriented Framework for Risk and Reliability Analysis

3520.240 • • • • **Industry

162 Simulation/Optimization Tools for System Variability Analysis 3520.270 • •


3520.280 • • • • *FEMA, CIA


3520.290 • • •


3520.310 • • • **Microelectronics,

Sematech

165Reliability Predictions for Advanced Electronics in Smoke Environments

3520.320 • • • • • • *NRC, FAA

**Telecommunications

168 Security of Bulk Power Systems 3520.330 • • • • • • *FBI, CIA **Public

utilities

171 Science on the Microdomain 3522.010 • • • • • • •

172 Autonomous MicroChem Laboratory (µChemLab) 3522.020 • • • • • • • • • • • •*NIJ, EPA, Veterans,

DARPA, NIH **Industry,

universities


3522.030 • • • •


3530.030 • • • •*GSA, DOS, DOE TSWG

**Building Construction

Architect-Engineering

178Background Radiation Anisotropy Measurement Sensor (BRAMS)

3530.050 • • *NASA **University

Collaboration



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3530.090 • • • • *Tagging & Tracking,

DEA, Customs, FBI

179 Microcode Evaluation 3530.110 • • •

179Real-Time Image Analysis Using Field-Programmable Gate Arrays

3530.120 •

180Advanced 3-D Sensing and Visualization System for Unattended Monitoring

3530.130 • • • • • *DOE, EM

180 System-of-Labs Direct Fabrication Technology 3531.020 • •

182 Poco Switch Tubes 3531.140 • •

182Chemiresistors Based on Metal-Loaded Polymers for Solvent Spill Detection

3531.150 • • • • •

183 Advance Neutron-Tube Design and Producibility 3531.160 • •


3531.170 • • • • •

184 Dynamical Properties of Polymers: Computational Modeling 3531.180 • • •

188 Broadening Mechanism in 2-D Excitonic and Electron Gases 3531.190 •


3531.210 • •

185 Interfacial Reactions in Ceramic Systems 3531.220 • • • • • • •


3531.230 • • • • •



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187Biophotonic Materials for Optical Encryption and Noncomputing

3531.240 • •

188 Low-Stress Amorphous Diamond: A New Material for Sensors 3531.250 • •

189Nanoengineered Cu-Al Defects in Al: A Prototype System for Corrosion

3531.260 • •

190 Novel Energy-Conversion Devices of Icosahedral Borides 3531.270 • • • •

191 Ion-Mobility Spectroscopy of Biological Materials 3531.280 • • • •

192 Visualization Tools for MEMs Designs in a Virtual 3-D World 3531.290 • • •

191 Direct Fabrication of Planar Solid-Oxide Fuel Cells 3531.310 • • • •

192 Micromachining with Ultra-Short Pulsewidth Lasers 3531.320 • • • •

193 Molecular Characterization of Energetic Material Initiation 3531.330 • •

196 Chemical Feedstocks for the Future: Oxidative Dehydrogenation 3532.010 • • • •

196 Global Approaches to Infrastructural Analysis (GAIA) 3532.030 • • • • • • • •

194 Engineering Complex Distributed Systems 3532.070 • • • •

198 Laser Communication Nanosatellites 3532.080 • • • • *NASA


3532.090 • •


3532.110 • •



te M

anag

emen

t

Ene

rgy

Eff

icie

ncy

Ren

ewab

le E

nerg

y

ES&

H

Env

iron

men

tal R

esto

ratio

n

Fos

sil E

nerg

y

Rad

ioac

tive-

Was

te M

anag

emen

t

Eco

nom

ic I

mpa

ct

Ene

rgy

Res

earc

h

Int

ellig

ence

& N

atio

nal S

ecur

ity

Nuc

lear

Ene

rgy

Sci

ence

Edu

catio

n &

Tec

hnic

al I

nfor

mat

ion

Def

ense

Pro

gram

s

Dep

artm

ent o

f D

efen

se (

DoD

)

Oth

er F

eder

al A

genc

ies*

Oth

er (

Indu

stry

, Con

sort

ia,…

)**

Oth

er F

eder

al A

genc

ies*

Oth

er

(Ind

ustr

y, C

onso

rtia

…)*

*


201 Microfluidic Engineering 3532.120 • • • •

199 Accelerator Technologies for Emerging Threats 3532.130 • •

204Technologies for System-Level Innovations in Ballistic Missile Defense

3532.140 • • •


3532.150 • • • • • *NRO

203 Technologies for Countering C/B Terrorism 3532.160 • • •

205 Aerosol Stand-Off Detection Test-Bed 3532.170 • • • • *FBI, FEMA

206


3532.180 • • •


3532.190 • • •**Ceramic, metallurgical,

& pharmaceutical

industries

208 Development of Fiber-Laser–Based LIF for Detection of SO2 3532.210 • • • • *NASA, EPA


3532.220 • • •

210 IFSAR Tree Phenomenology and Coherence Normalization 3532.230 • • • • •

210 Electric Launcher for Defense Applications 3532.240 • • •

212 SAM Telemetry for Measurements While Drilling 3533.050 • • •



te M

anag

emen

t

Ene

rgy

Eff

icie

ncy

Ren

ewab

le E

nerg

y

ES&

H

Env

iron

men

tal R

esto

ratio

n

Fos

sil E

nerg

y

Rad

ioac

tive-

Was

te M

anag

emen

t

Eco

nom

ic I

mpa

ct

Ene

rgy

Res

earc

h

Int

ellig

ence

& N

atio

nal S

ecur

ity

Nuc

lear

Ene

rgy

Sci

ence

Edu

catio

n &

Tec

hnic

al I

nfor

mat

ion

Def

ense

Pro

gram

s

Dep

artm

ent o

f D

efen

se (

DoD

)

Oth

er F

eder

al A

genc

ies*

Oth

er (

Indu

stry

, Con

sort

ia,…

)**

Oth

er F

eder

al A

genc

ies*

Oth

er

(Ind

ustr

y, C

onso

rtia

…)*

*


214 Design-for-Manufacturability Applied to Photovoltaic Modules 3533.070 • • •

212 Advanced Geosphere Transport Simulation 3533.160 • • •

214 Low-Work-Function Thermionic Emission Materials 3533.170 • • •

211 Power-Grid Reliability and Restructuring Policy Changes 3533.180 • • • • • • •*Federal Energy

Regulatory Commission

(FERC) & North

American Electric


3534.020 • • • • • • • • • • •

216 LIGA Micromachining 3534.030 • • • •

216 Applied Microfluidics Science 3534.040 • • •

218Computational Simulations of Self-Assembling Macro-Systems by Direct Fabrication of Microscopic Structured Materials

3535.130 • •

218Self-Stabilizing Optical Solitons and High-Intensity Laser Plasma Channels for Diffraction-Free Propagation and Robust Power Compression

3535.140 • •

222 Novel Materials for Hydrogen Storage 3535.150 • •

220Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

3535.160 • •


3535.170 • • • • • • •

224 Z-Pinch–Driven Isentropic Compression 3535.180 • • •



te M

anag

emen

t

Ene

rgy

Eff

icie

ncy

Ren

ewab

le E

nerg

y

ES&

H

Env

iron

men

tal R

esto

ratio

n

Fos

sil E

nerg

y

Rad

ioac

tive-

Was

te M

anag

emen

t

Eco

nom

ic I

mpa

ct

Ene

rgy

Res

earc

h

Int

ellig

ence

& N

atio

nal S

ecur

ity

Nuc

lear

Ene

rgy

Sci

ence

Edu

catio

n &

Tec

hnic

al I

nfor

mat

ion

Def

ense

Pro

gram

s

Dep

artm

ent o

f D

efen

se (

DoD

)

Oth

er F

eder

al A

genc

ies*

Oth

er (

Indu

stry

, Con

sort

ia,…

)**

Oth

er F

eder

al A

genc

ies*

Oth

er

(Ind

ustr

y, C

onso

rtia

…)*

*



3535.190 • • • *NSA, CIA

226 Semiconductor Filament Lasers 3535.210 • • • •

226 Development of Membrane Devices Using AlN and SiC Films 3537.010 • •


3537.020 • • • •**Any security operation

involving explosives

detection


3537.030 • • • •

228 Picosecond Particle Velocity Measurements 3537.040 • • •

228 Particle-Level Modeling of Flows of Concentrated Suspensions 3537.050 • • • • **Coatings Consortium


3537.060 •

230 Nondestructive Evaluation of Wind Turbine Blades 3537.070 • • • •


3537.080 • • • •


3537.110 • • • • •

232 Novel Biosensor Fabrication Techniques 3537.120 • • • • •

233 Design for 100-Year-Life Prototype 3537.130 • • • • • *FEMA **Civil

construction, insurance



te M

anag

emen

t

Ene

rgy

Eff

icie

ncy

Ren

ewab

le E

nerg

y

ES&

H

Env

iron

men

tal R

esto

ratio

n

Fos

sil E

nerg

y

Rad

ioac

tive-

Was

te M

anag

emen

t

Eco

nom

ic I

mpa

ct

Ene

rgy

Res

earc

h

Int

ellig

ence

& N

atio

nal S

ecur

ity

Nuc

lear

Ene

rgy

Sci

ence

Edu

catio

n &

Tec

hnic

al I

nfor

mat

ion

Def

ense

Pro

gram

s

Dep

artm

ent o

f D

efen

se (

DoD

)

Oth

er F

eder

al A

genc

ies*

Oth

er (

Indu

stry

, Con

sort

ia,…

)**

Oth

er F

eder

al A

genc

ies*

Oth

er

(Ind

ustr

y, C

onso

rtia

…)*

*



3537.140 • •

234 In Situ and Ex Situ Investigations of Lateral Composition 3537.150 • • • •


3537.160 • •

235 Living Tissue Engineering 3537.170 •




Pg # Title Case Number Aer

onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

10 Catalytic Membrane Sensors 3502.030 • • • •

9Photonic Bandgap Structures as a Gateway to Nanophotonics

3502.040 • • • • •


3502.050 • • • • • • • • • •

12 Ultra-Hard Multilayer Coatings 3502.080 • • • • • • • • •

14Scanning Probe–Based Processes for Nanometer-Scale Device Fabrication

3502.090 • • • • •

15Molecular-Scale Lubricants for Micromachine Applications

3502.110 • • • • •

16Surface-Micromachined Flexural Plate-Wave Device Integrated on Silicon

3502.120 • • • • • • • •


3502.140 • • • • •


3502.170 • • • • • • •


3502.190 • • • • • •

19 Monolithic Structures for Nanoseparation 3502.210 • • • • • • • •

21Fundamental Aspects of Micromachine Reliability

3502.220 • •

24Enabling Science and Technology for Cold-Spray Direct Fabrication

3502.230 • • • • • • • • • •

Appendix G: Dual-Benefit Areas and Single-Use Categories



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


22Atomic-Level Studies of Surfactant-Directed Materials Growth

3502.240 • • •

26Intelligent Polymers for Nanodevice Performance Control

3502.250 • •

25Freeforming of Ceramics and Composites from Colloidal Slurries

3502.260 • • • • •

26 Quantum Dot Arrays 3502.270 • • • • •

27Laser-Assisted Arc Welding for Aluminum Alloys

3502.280 • • • • • • •

28 Reactivity of Metal-Oxide Surfaces 3502.310 • • • •

29Exploiting LENS Technology Through Novel Materials

3502.320 • • • • • •

34Parallel Quantum Chemistry for Material Aging and Synthesis

3504.010 • • • • •


3504.020 • • • • • • • • •

35Automated Geometric Model Builder Using Range Image Sensor Data

3504.050 • • • •


3504.060 • • • • • • • • • • • •

36Density-Functional Theory for Classical Fluids at Complex Interfaces

3504.070 • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)



3504.090 • • • • • • • • • • • • • • •

38Fast and Easy Parallel I/O for Efficient Scientific Computing

3504.120 • • • • •


3504.130 • • • • • • • •

40Parallel Computational Chemistry Using Constraints

3504.140 • • •

40Massively Parallel Ab Initio Validation for ASCI Materials Aging

3504.160 • • • • •


3504.170 • • • • • • •

44An Investigation of Wavelet Bases for Multiscale, Grid–Based Simulation

3504.180 • • • • •

41Integrated Quantum/Classical Modeling of Hydrogenic Materials

3504.190 • • • •


3504.210 • • • •


3504.220 • • • • • • • • • • • •

48Global Optimization for Engineering Science Problems

3504.230 • • • • • • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


49Dynamic Simulation of Mechanical Systems with Intermittent Contacts

3504.240 • • • • • •

43From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment

3504.250 • • • • • • • • • • • •

47Emergent Behavior of Large Swarms of Intelligent Agents

3504.260 • • • • •

50Parallel Combinatorial Optimization for Scheduling Problems

3504.270 • • • •

50Programming Paradigms for Massively Parallel Computers

3504.280 • • • • • •


3504.290 • • • •

52Scalable Tools for Massively Parallel Distributed Computing

3504.310 • • •

52Massively Parallel Methods for Simulating the Phase Field Model

3504.320 • • • •

53 Visual Explanation and Insight 3504.330 • • • • •

58Wafer Fusion for Integration of Semiconductor Materials and Devices

3506.110 • • • • •


3506.120 • • • • • • •

59Virtual Reactor for the Semiconductor Manufacturing Plant of the Future

3506.140 • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)



3506.160 • • • • •

61Agile Prototyping of Microelectromechanical Systems (MEMS)

3506.180 • • • • • • •

57Advanced Concepts for High-Power VCSELs and VCSEL Arrays

3506.190 • • • • •

62Midwave-Infrared (2–6 µm) Emitter–Based Chemical Sensor Systems

3506.210 • • • • •

62A Novel Nondestructive Silicon-on-Insulator Nonvolatile Memory

3506.230 • • • • •

64Integration of Optoelectronics and MEMS by Free-Space Microoptics

3506.240 • • • • •


3506.250 • • • • • • •

66Metal Micro-Heat-Pipe Substrates for High-Power-Density Electronics

3506.260 • • • • • • •

68Integration of Microsensor Technology into a Miniature Robotic Vehicle

3506.270 • • •

66 Vacuum Encapsulation of MEMS Structures 3506.280 • • • • • • • • • •

67Massively Parallel Sensor Arrays for Volatile Organic Detection

3506.290 • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

hoto

nics

Ene

rgy

Fle

xibl

e C

ompu

ter-

Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

tion,

& W

aste

Mgm

t.

Sen

sors

& S

igna

l Pro

cess

ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

ogie

s

Sys

tem

s M

anag

emen

t Tec

hnol

ogie

s

Def

ense

-Rel

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(m

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Dua

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se (

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and

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Non

-Def

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-Rel

ated

(m

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pure

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3506.310 • • • • • •

68 Precision-Formed Micromagnets 3506.320 • • • • • •

70Time-Resolved Ion-Beam–Induced Charge-Collection (TRIBICC) Imaging

3506.330 • •

74 Composite-Resonator Surface-Emitting Lasers 3506.340 • • • • • •

73Role of Defects in III-Nitride–Based Electronics

3506.350 • • • •

74Ultra–Low-Power Sensors for Microtelemetry Systems

3506.360 • • • • • •

72Double Quantum-Well Long-Wavelength Optoelectronic Devices

3506.370 • • • • •

75The Development of Integrated Chemical Microsensors in GaAs

3506.380 • • • • •

76Monolithic Integrated of VCSELs and Detectors for Microsystems

3506.410 • • • • •

77AlGaN Materials Engineering for Integrated Multifunction Systems

3506.420 • • • • • • • • • • •

71Compliant Substrates for Epitaxial Integration of Dissimilar Materials

3506.430 • • • • • •

78 Post-Processed Integrated Microsystems 3506.440 • • • • •

83Using Higher-Order Gradients to Modeling Localization Phenomena

3508.040 • • • •



onau

tics

App

lied

Mol

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Cer

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s

Com

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tes

Com

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Int

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Med

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Mic

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Sys

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Def

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-Rel

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Non

-Def

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-Rel

ated

(m

ostly

or

pure

ly)


81Enhanced Vapor-Phase Diffusion in Porous Media

3508.060 • • • • •

82Stress Evaluation and Model Validation Using Laser Ultrasonics

3508.110 • • • • • • • • • • •


3508.120 • • • • • •

84

Development, Implementation, and Experimental Validation of the Lattice Boltzmann Method for Modeling Three-Dimensional Complex Flows

3508.130 • • • • • • •

86Capturing Recrystallization of Metals with a Multiscale Material Model

3508.140 • • • • •

88Nondeterministic Modeling in Engineering Science

3508.150 • • • • • • • • • • •

88 Lagrangian Modeling of Radiative Transport 3508.160 • •


3508.170 • • •

90Dispersive Measurements of Velocity in Heterogeneous Materials

3508.180 • • • • • • •


3508.190 • • • • • • • •


3508.210 • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

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Dat

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Per

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Ele

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& P

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Im

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s

Hig

h-Pe

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Hig

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man

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etal

s &

Allo

ys

Int

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men

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Mat

eria

ls S

ynth

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& P

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g

Med

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Tec

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Mic

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Mic

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Pho

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Pol

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-Rel

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Non

-Def

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-Rel

ated

(m

ostly

or

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91Micromechanical Failure Analyses for Finite-Element Polymer Modeling

3508.220 • • • • • • • •


3508.230 • • • •

93

A Phenomenological Model for Multicomponent Transport with Electrochemical Reactions in Concentrated Solutions

3508.240 • • • • •

98Laser-Spray Fabrication for Net-Shape Rapid Product Realization

3510.460 • • • • • • • • • • •


3510.510 • • • • •

97Ultra-Precise Assembly of Microelectromechanical Systems (MEMS)

3510.540 • • • • • •

100Finite-Element Meshing Approached as a Global Minimization Process

3510.570 • • • • • •

102Application of Parallel Mechanism Technology to Manufacturing

3510.580 • • • •


3510.590 • • • • • • • • •

102Standard Cells for Microelectromechanical Systems (MEMS)

3510.610 • • • • • • •

104 Laser Wire Deposition for Fully Dense Shapes 3510.620 • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

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e &

Per

iphe

rals

Ele

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nics

& P

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nics

Ene

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Fle

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ompu

ter-

Inte

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ed M

anuf

actu

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Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

Hig

h-Pe

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man

ce C

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ting

& N

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ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

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ent P

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g E

quip

men

t

Mat

eria

ls S

ynth

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& P

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g

Med

ical

Tec

hnol

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Mic

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& N

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n

Mic

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& O

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Pho

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Pol

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Def

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and

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ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


105High-Throughput Dry Processes for Large-Area Devices

3510.630 • • • •


3510.640 • • • • • • •

103 Scripting for Video Inspection 3510.660 • • • • • • • •

106Advanced Machining Processes for Microfabrication

3510.670 • • • • • • • • •


3510.680 • • • • • •

108 Advanced Production Planning Models 3510.690 • • • • • • • •


3511.010 • • • • • •


3511.020 • • •

114 Immersive CAD 3511.040 • • • • •

114Automatic Planning of Life-Cycle Assembly Processes

3511.050 • • • • • •

116 Analysis of Very Large Assemblies 3511.070 • • • • • •

111Enabling Human Skills with Cooperative Automation

3511.080 • • • • •

116 Cloud To CAD 3511.090 • • • • • •

118 Ergonomics in Life-Cycle Assembly Processes 3511.110 • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

iphe

rals

Ele

ctro

nics

& P

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nics

Ene

rgy

Fle

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ompu

ter-

Inte

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ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

Dis

play

s

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h-Pe

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ting

& N

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ng

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h-Pe

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man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

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ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

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ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

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n

Mic

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& O

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cs

Pho

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ater

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Pol

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n M

in.,

Rem

edia

tion,

& W

aste

Mgm

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Sen

sors

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ing

Sof

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Sur

face

Tra

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ion

Tec

hnol

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s

Sys

tem

s M

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Def

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-Rel

ated

(m

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Dua

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ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


117Feature Reduction of Geometric Solid Models for Analysis Tools

3511.120 • • • • • • • • •

119 System Surety Life-Cycle Engineering 3511.130 • • • •

123 Content–Based Search of Geometric Databases 3512.160 • • • • • • •

124Integrated Service Provisioning in an “IPv6 over ATM” Research Network

3512.170 • • • •

125Virtual Desktop Engineering with Integrated Multimedia Data

3512.180 • • • •

123Mission Surety for Large-Scale Real-Time Information Systems

3512.190 • • • • • • • •

126 Scaled ATM End-to-End Encryption 3512.220 • • •

128Network Surety Modeling for Wireless ATM Networks

3512.230 • • •

130Low-Power, Reduced-Computation, Public-Key Protocols

3512.240 • • • • • • •

126Ten-to-One-Hundred-Gigabit/Second Network Enabling R&D

3512.250 • • • •


3512.260 • • •

131AVATAR — Navigating and Mining in Massive Data

3512.270 • • • • • •


3512.280 • • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

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e &

Per

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Ele

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Fle

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Inte

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etal

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Allo

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Int

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men

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Mat

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ls S

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Med

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Tec

hnol

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Mic

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Mic

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Pho

toni

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ater

ials

Pol

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n M

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Rem

edia

tion,

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Sen

sors

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ing

Sof

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Sur

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Tra

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Tec

hnol

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s

Sys

tem

s M

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s

Def

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-Rel

ated

(m

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or

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Dua

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and

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rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


136Electrokinetic Immunoaffinity Chemical Sensors

3516.050 • • • • • • •

136Information-Efficient Spectral Imaging System (ISIS)

3516.060 • • • • •


3516.070 • •

135Sampling and Sensing Systems for High-Priority Analytes

3516.080 • • • • • • • •

138Automated Vegetation Height Measurement for Automatic Terrain Mapping

3516.090 • •

138Sparse Geophysical Networks for Monitoring Deep Targets

3516.110 • • • •

139 Miniature Bioaerosol Concentrator 3516.120 • • •


3516.130 • • • •


3516.140 • • • • • •


3516.150 • • • • • •

142ATR/Exploitation Utilizing Ultra–High-Resolution, Complex SAR Imaging

3516.160 • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

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Ele

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nics

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Inte

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Allo

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Int

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& P

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Med

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Tec

hnol

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Mic

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Mic

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aste

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ing

Sof

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Sur

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Tra

nspo

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ion

Tec

hnol

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Sys

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s M

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Def

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-Rel

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(m

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or

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Dua

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and

non-

defe

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rela

ted)

Non

-Def

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-Rel

ated

(m

ostly

or

pure

ly)



3518.030 • • • • • • •

148Rapid Screening of Complex Chemical Samples Via Capillary Array Analysis

3518.050 • •

148Designed Synthesis of Controlled Degradative Materials

3518.060 • • •

150Mechanistic Models for Radionuclide Desorption from Soils

3518.070 • •


3518.080 • • •


3518.090 • • • • •

153 Hybrid Vehicle Engine Development 3518.110 • • •

149 Adaptive 3-D Sensing 3518.120 • • • • •154 Aqueous Organic Sensor 3518.130 • •


3518.140 • • • • • • • • • •

156An Electromagnetic Imaging System for Environmental Site Reconnaissance

3518.150 • • • • •

160Reliability Degradation Due to Stockpile Aging

3520.210 • • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

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gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

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Dat

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Per

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etal

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Allo

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Int

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ls S

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& P

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Tec

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Tra

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-Def

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-Rel

ated

(m

ostly

or

pure

ly)



3520.220 • • •

160Precursors to Failure of Oxides and Metal Lines in CMOS Technology

3520.230 • •

162An Extensible Object-Oriented Framework for Risk and Reliability Analysis

3520.240 • • • • • • •

162Simulation/Optimization Tools for System Variability Analysis

3520.270 • • • • • •


3520.280 • • • • •


3520.290 • • • • • •


3520.310 • •

165Reliability Predictions for Advanced Electronics in Smoke Environments

3520.320 • • • •

168 Security of Bulk Power Systems 3520.330 • • • •171 Science on the Microdomain 3522.010 • • • • • •

172Autonomous MicroChem Laboratory (µChemLab)

3522.020 • • • • • • • • • • • • • • • • •


3522.030 • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

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e &

Per

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rals

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nics

& P

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ition

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s

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h-Pe

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h-Pe

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man

ce M

etal

s &

Allo

ys

Int

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ent P

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ssin

g E

quip

men

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Mat

eria

ls S

ynth

esis

& P

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g

Med

ical

Tec

hnol

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Mic

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& N

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abri

catio

n

Mic

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& O

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roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

n M

in.,

Rem

edia

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aste

Mgm

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Sen

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l Pro

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ing

Sof

twar

e

Sur

face

Tra

nspo

rtat

ion

Tec

hnol

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s

Sys

tem

s M

anag

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t Tec

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s

Def

ense

-Rel

ated

(m

ostly

or

pure

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Dua

l-U

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nse

and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)



3530.030 • • • • •

178Background Radiation Anisotropy Measurement Sensor (BRAMS)

3530.050 • •


3530.090 • • • •

179 Microcode Evaluation 3530.110 •

179Real-Time Image Analysis Using Field-Programmable Gate Arrays

3530.120 • • • •

180Advanced 3-D Sensing and Visualization System for Unattended Monitoring

3530.130 • • • •

180 System-of-Labs Direct Fabrication Technology 3531.020 • • •

182 Poco Switch Tubes 3531.140 •

182Chemiresistors Based on Metal-Loaded Polymers for Solvent Spill Detection

3531.150 • • • • • • •

183Advance Neutron-Tube Design and Producibility

3531.160 • •


3531.170 • • • •

184Dynamical Properties of Polymers: Computational Modeling

3531.180 • • • •

188Broadening Mechanism in 2-D Excitonic and Electron Gases

3531.190 • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

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e &

Per

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Ele

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nics

& P

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Inte

grat

ed M

anuf

actu

ring

Hig

h-D

efin

ition

Im

agin

g &

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play

s

Hig

h-Pe

rfor

man

ce C

ompu

ting

& N

etw

orki

ng

Hig

h-Pe

rfor

man

ce M

etal

s &

Allo

ys

Int

ellig

ent P

roce

ssin

g E

quip

men

t

Mat

eria

ls S

ynth

esis

& P

roce

ssin

g

Med

ical

Tec

hnol

ogy

Mic

ro-

& N

anof

abri

catio

n

Mic

ro-

& O

ptoe

lect

roni

cs

Pho

toni

c M

ater

ials

Pol

lutio

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in.,

Rem

edia

tion,

& W

aste

Mgm

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Sen

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& S

igna

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ing

Sof

twar

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face

Tra

nspo

rtat

ion

Tec

hnol

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s

Sys

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s M

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s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

l-U

se (

defe

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and

non-

defe

nse-

rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)



3531.210 • • • • • • •

185 Interfacial Reactions in Ceramic Systems 3531.220 • • • • • •


3531.230 • • • • • • • • • • •

187Biophotonic Materials for Optical Encryption and Noncomputing

3531.240 • • • • • • • •

188Low-Stress Amorphous Diamond: A New Material for Sensors

3531.250 • • • • •

189Nanoengineered Cu-Al Defects in Al: A Prototype System for Corrosion

3531.260 • • •

190Novel Energy-Conversion Devices of Icosahedral Borides

3531.270 • • •

191Ion-Mobility Spectroscopy of Biological Materials

3531.280 • •

192Visualization Tools for MEMs Designs in a Virtual 3-D World

3531.290 • • • • • •

191Direct Fabrication of Planar Solid-Oxide Fuel Cells

3531.310 • • • • • •

192Micromachining with Ultra-Short Pulsewidth Lasers

3531.320 • • • • • • •

193Molecular Characterization of Energetic Material Initiation

3531.330 • • •

196Chemical Feedstocks for the Future: Oxidative Dehydrogenation

3532.010 •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

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a St

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e &

Per

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ctro

nics

& P

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Ene

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Fle

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ter-

Inte

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ed M

anuf

actu

ring

Hig

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ition

Im

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play

s

Hig

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rfor

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ce C

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ting

& N

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Hig

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etal

s &

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Int

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ent P

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men

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Mat

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ls S

ynth

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& P

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Med

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Mic

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& O

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Pho

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ater

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Pol

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& W

aste

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& S

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ing

Sof

twar

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Tra

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s

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s

Def

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(m

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or

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Dua

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se (

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and

non-

defe

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rela

ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


196Global Approaches to Infrastructural Analysis (GAIA)

3532.030 • • • • • • •

194 Engineering Complex Distributed Systems 3532.070 • • • • • • •

198 Laser Communication Nanosatellites 3532.080 • • • • • • • •


3532.090 • •


3532.110 • •

201 Microfluidic Engineering 3532.120 • • • •

199 Accelerator Technologies for Emerging Threats 3532.130 • • •

204Technologies for System-Level Innovations in Ballistic Missile Defense

3532.140 • • • • • • • • •


3532.150 • • • •

203 Technologies for Countering C/B Terrorism 3532.160 • • • • • • • •

205 Aerosol Stand-Off Detection Test-Bed 3532.170 • •

206


3532.180 • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

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g

Dat

a St

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e &

Per

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Ele

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nics

& P

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nics

Ene

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ter-

Inte

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anuf

actu

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Hig

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ition

Im

agin

g &

Dis

play

s

Hig

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rfor

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ce C

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ting

& N

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ng

Hig

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rfor

man

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etal

s &

Allo

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Int

ellig

ent P

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men

t

Mat

eria

ls S

ynth

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& P

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ssin

g

Med

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Tec

hnol

ogy

Mic

ro-

& N

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& O

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Pho

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ater

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& W

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ing

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Def

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(m

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se (

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and

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ted)

Non

-Def

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-Rel

ated

(m

ostly

or

pure

ly)



3532.190 • • • • • • • • •

208Development of Fiber-Laser–Based LIF for Detection of SO2

3532.210 • • • •


3532.220 • •

210IFSAR Tree Phenomenology and Coherence Normalization

3532.230 • • • • • •

210 Electric Launcher for Defense Applications 3532.240 • • •

212SAM Telemetry for Measurements While Drilling

3533.050 • •

214Design-for-Manufacturability Applied to Photovoltaic Modules

3533.070 • • •

212 Advanced Geosphere Transport Simulation 3533.160 • • • • •

214Low-Work-Function Thermionic Emission Materials

3533.170 • • •

211Power-Grid Reliability and Restructuring Policy Changes

3533.180 • • •


3534.020 • • • • • • • • • • • •

216 LIGA Micromachining 3534.030 • • • • •216 Applied Microfluidics Science 3534.040 • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

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gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

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e &

Per

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Ele

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nics

& P

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Ene

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ompu

ter-

Inte

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anuf

actu

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Hig

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ition

Im

agin

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s

Hig

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ce C

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ting

& N

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Hig

h-Pe

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man

ce M

etal

s &

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ys

Int

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ent P

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g E

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men

t

Mat

eria

ls S

ynth

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& P

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g

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Mic

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Pho

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ater

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Pol

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& W

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& S

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ing

Sof

twar

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Tra

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ion

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s

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Def

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(m

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or

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Dua

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se (

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and

non-

defe

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ted)

Non

-Def

ense

-Rel

ated

(m

ostly

or

pure

ly)


218

Computational Simulations of Self-Assembling Macro-Systems by Direct Fabrication of Microscopic Structured Materials

3535.130 • • • •

218

Self-Stabilizing Optical Solitons and High-Intensity Laser Plasma Channels for Diffraction-Free Propagation and Robust Power Compression

3535.140 • • • •

222 Novel Materials for Hydrogen Storage 3535.150 • • • •

220

Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

3535.160 • • • •


3535.170 • • • • • •

224 Z-Pinch–Driven Isentropic Compression 3535.180 • • • •


3535.190 • • • • • •

226 Semiconductor Filament Lasers 3535.210 • • • • • • • • • • • • • •

226Development of Membrane Devices Using AlN and SiC Films

3537.010 • • •


3537.020 • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

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rals

Ele

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nics

& P

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nics

Ene

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Fle

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Inte

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Hig

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Im

agin

g &

Dis

play

s

Hig

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ce C

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ting

& N

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ng

Hig

h-Pe

rfor

man

ce M

etal

s &

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ys

Int

ellig

ent P

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g E

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men

t

Mat

eria

ls S

ynth

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& P

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g

Med

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Tec

hnol

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Mic

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& N

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Mic

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Pho

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ater

ials

Pol

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in.,

Rem

edia

tion,

& W

aste

Mgm

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& S

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cess

ing

Sof

twar

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Sur

face

Tra

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hnol

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s

Sys

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s M

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s

Def

ense

-Rel

ated

(m

ostly

or

pure

ly)

Dua

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se (

defe

nse

and

non-

defe

nse-

rela

ted)

Non

-Def

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-Rel

ated

(m

ostly

or

pure

ly)



3537.030 • •

228 Picosecond Particle Velocity Measurements 3537.040 • • •

228Particle-Level Modeling of Flows of Concentrated Suspensions

3537.050 • • • • • • • •


3537.060 • •

230Nondestructive Evaluation of Wind Turbine Blades

3537.070 • • • • •


3537.080 • • • • • • •


3537.110 • • • • •

232 Novel Biosensor Fabrication Techniques 3537.120 • • • • • • •

233 Design for 100-Year-Life Prototype 3537.130 • • • •


3537.140 • • • • •

234In Situ and Ex Situ Investigations of Lateral Composition

3537.150 • • • • • • • •



onau

tics

App

lied

Mol

ecul

ar B

iolo

gy

Cer

amic

s

Com

posi

tes

Com

pute

r Si

mul

atio

n &

Mod

elin

g

Dat

a St

orag

e &

Per

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rals

Ele

ctro

nics

& P

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nics

Ene

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Fle

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s

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ting

& N

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Hig

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man

ce M

etal

s &

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Int

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ent P

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men

t

Mat

eria

ls S

ynth

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& P

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g

Med

ical

Tec

hnol

ogy

Mic

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& N

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lect

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Pho

toni

c M

ater

ials

Pol

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n M

in.,

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& W

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Sen

sors

& S

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ing

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Sur

face

Tra

nspo

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s M

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Def

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-Rel

ated

(m

ostly

or

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se (

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Non

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-Rel

ated

(m

ostly

or

pure

ly)



3537.160 • • • • •

235 Living Tissue Engineering 3537.170 • • •




Index


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

AAccelerated Strategic ComputingInitiative (ASCI)

Turbulent flows, 34-35Materials aging, 40-41

AccelerationMultipole, 229Sensor, 226

AcceleratorsPulse-powered, 199Z-pinch, 38

Acetylene, 92ACIS

see Applications of CollectiveIntelligence Systems

Acousticsee Surface Acoustic Wave

Acoustoelasticity, 82ActiveX, 107Adams, D. P.

Advanced machining, 106Laser micromachining, 192

Adaptive visualization (AVATAR), 131see also: Data mining

Adenosine triphosphate, 231Adolf, D. B. 91Adriaans, M. J. 178Adsorbate kinetics, 28Aerodynamic lens

Bioaerosol, 139Cold-spray, 24

Aerogel, 225Aeroshell, 231Agent

Distributed systems, 194-195Infrastructure, 164-165Intelligent, 47

Ahrens, E. H. 209Aidun, J. B. 90Alam, M. K. 148Alber, E. S. 90ALEGRA (code)

Parallel I/O, 38Rayleigh-Tayor, 201Unstructured, grid, 51

AlkanesHydrogen production, 152Oxidative dehydrogenation, 196-197

Allen, J. J. 102Allendorf, S. W. 92Allerman, A. A.

Chemical sensor, 62Composite resonator, 74High-power Vertical-Cavity Surface-Emitting Laser, 57Microsystems, 76Nanosatellite, 198Optical sensor, 65

Optoelectronics, 64Selective oxidation, 60Solar and photonic, 202Wafer fusion, 58

Alternator, 153Altimeter,

see High Altitude Doppler Radar AltimeterAlvin, K. F.

Characterizing uncertainty, 46Test and simulation levels, 94

Ames, A. L.Cloud to Computer Aided Design, 116Immersive Computer Aided Design, 114

AMLS,see Automated MultilevelSubstructuring

Ammerlahn, H. R. 113Anderson, C. 68Anderson, D. J. 165Anderson, R. A. 26Anderson, R. J.

Automation, 111Ergonomics, 118

Anex, D. S.Capillary analysis, 148Chemical sensor, 136Nanoseparation, 19

AnimationDocumentation, 112-113Virtual engineering, 125

AnisotropyBackground Radiation Anisotropy MeasurementSensor, 178Magnet, 69

AnnealNonvolatile memory, 63Solar cells, 202

Antenna, 206Anthrax sensor, 142Antibody

Bioaffinity array, 142Electrokinetic sensors, 136Fabrication, 232Immunoassay, 225

Antitoxin development, 203Applications of Collectively IntelligentSystems, 117ARCHIMEDES (code), 130Architectural Surety

100-year-life, 233PRONTO3D, 177

Arc welding, 27Arguello, J. G., Jr. 207Armature, 210-211Armor penetration, 209Armstrong, R. C.

Commodity interconnects, 130Distributed computing, 52

Index


Asay, J. R. 224Asbill, R. E. 64ASCI

see Accelerated Strategic Computing InitiativeAselage, T. L. 190Ashby, C. I. H.

Dry etching, 70Large-area etching, 105Selective oxidation, 60

Asher, R. B. 210Ashley, C. S. 225Assay

Bead, 141Immuno, 225

Asteroid, 5Asynchronous Transfer Mode

High-performance interconnects, 130Mobile switches, 128Scalable, 126Wireless, 128

AtomAdatom, 184Defect chemistry, 28Diffusion, 33Materials growth, 22Nanostructures, 20Picoseconds, 43Parallel computation, 40Porous structures, 222Recrystallization, 86Surface hardening, 183

Atom-Tracker (AT-STM)see Scanning-Tunneling Microscopy

ATMsee Asynchronous Transfer Mode

ATPsee Adenosine TriPhosphate

ATRsee Automatic Target Recognition

Attaway, S. W. 177Attenuation (monitored natural), 150Atwood, C. L. 98Aurand, J. F.

Electromagnetic attack, 206Imaging, 70

Authenticate, 130AutoCAD

Geometric databases, 123Microelectromechanical Systems, 192

AutomatedCooperative assistants, 111Documentation, 112Intelligent controls, 111Life-cycle assembly, 114Model builder, 35Terrain mapping, 138

Automated Multilevel Substructuring,235

Automatic Target RecognitionObscured targets, 142Synthetic Aperture Radar, 140

Ultra-high-resolution, 142AVATAR

see Adaptive VisualizationAZTEC (code), 50-51

BBaca, A. G.

Chemical microsensors, 75Electronic defect, 73Environmental reconnaissance, 156Semiconductor laser, 226

BacteriaSensor, 136Spectroscopy, 191

Bacteriorhodopsin, 187Baer, M. R.

Colloidal slurry, 25Heterogeneous materials, 90

Baeza, A. R. 179Baker, A. B. 211Baldwin, J. M. 107Baldwin, M. D. 198Ballard, S. 212Ballistic missile, 204Bammann, D. J.

Localization modeling, 83Recrystallization modeling, 86

BandgapNanophotonics, 9Solar cells, 202-203Wide, 10-11

Barker, G. T. 212Barnaby, M. L. 38Bartel, L. C.

Geophysical networks, 138Surface Area Modulation telemetry, 212

Bartelt, N. C. 22Bartholomew, J. W. 67Barton, D. L. 167Battaile, C. C. 42Battery, 93Baty, R. S. 44Baucom, K. C. 59Benavides, G. L.

Filament laser, 226Laser micromachining, 192Manufacturing, 102Microfabrication, 106

Bennett, P. C. 171Benson, D. A.

Integrated circuit interconnections, 167Micro-heat-pipe, 66

Berg, T. M. 194Bespalko, S. J. 123Bickel, D. L. 138Bicrystal

Compliant substrates, 71Metal recrystallization, 86

Biefeld, R. M.Chemical sensor, 62

Index


Engineered nanostructure, 20Bieg, L. F. 102Bioaerosol, 139Bioaffinity, 142Biocavity, 251Biodetection, 203Biological Warfare Agent, 139Biophotonic, 187Bioreactor, 235Biosensor

Bioaffinity, 142Electrochemical redox, 232Fabrication, 232Immunoaffinity, 136Immunoassays, 225

Blair, D. S. 154Blake, R. J. 136Bliss, D. E.

Laser micromachining, 192Power compression, 218

Boehme, D. R. 216Boettcher, G. E. 182Bogdan, C. W. 165Bombardment, 190Bonivert, W. D. 216Borns, D. J. 150Boslough, M. B. 200Bouchard, A. M. 20Bow, W. J. 142Boyack, K. W. 53Boyle, T. J. 10Brady, P. V. 150Brainard, J. P. 183Braithwaithe, J. W. 166Brandt, J. M. 124Brazee, J. L. 114Breiland, W. G. 70Brightwell, R. B. 50Brinker, C. J.

Catalytic sensor, 10Fuel cells, 152Immunoassay biosensor, 225Nanocomposite, 186Sensing systems, 135

Brockmann, J. E.Cold-spray fabrication, 24Smoke environment, 165

Brooks, J. A. 29Brown, K. H. 84Brown, R. G.

Geometric solid model, 117Life-cycle assembly, 114Very large assemblies, 116

Brunett, B. A. 222Buchheit, T. E.

Laser wire deposition, 104Micro simulations, 42

Bujewski, G. E. 154Burchett, S. N. 66Burns, A. R. 14Burns, S. P.

Grid-based simulation, 44Modeling turbulent flows, 34

Buss, R. J. 105Butler, M. A. 191Butler, P. C.

Power system security, 168Stockpile aging, 160

BWAsee Biological Warfare Agent

Byrne, R. H. 68

CCAD

see Computer Aided DesignCAEC

see Capillary AffinityElectrochromatography

Caffey, T. W. 212Calibrate, 41Calton, T. L.

Ergonomics, 118Life-cycle assembly, 114

Camera (video), 103Cameron, S. M.

Ballistic missiles, 204Emerging threats, 199Filament lasers, 226Laser micromachining, 192Nanosatellite, 198Optical communication, 220Power compression, 218

Campbell, A. N. 106Campbell, J. E. 162Capillary Affinity Electrochromotography,

136Capillary (electrochromotography),

216-217Carichner, S. A. 172Carlson, D. C. 179Carlson, J. J.

3-D sensing, 149Unattended monitoring, 180Video inspection, 103

Carr, M. J.Degradative materials, 148Intelligent polymers, 26

Carr, R. D. 50Casalnuovo, S. A.

Chemical microsensor, 75Device fabrication, 14Integrated microsystems, 78Materials engineering, 77

Cascade (lasers), 62Catalytic

Chiral sensors, 147Membrane reactor, 152Membrane sensor, 10Oxidative dehydrogenation, 196-197

Cathode, 214-215Causey, R. A. 222

Index


Cavitysee Vertical-Cavity Surface-Emitting Laser

CBR see Cosmic Background Radiation

Centimeter-Years, 43Ceramic

Free-form fabrication, 25Interfacial reaction, 185Multilayer coating, 12Powder pressing, 207Switch tube, 182

Cesarano, J., IIIColloidal slurries, 25Fuel cells, 191Self-assembling macrosystems, 218

Chambers, R. S. 91Chambers, W. B. 172Chang, H. 198Charge-Collection, 70-71Chemiresistor

Low-power sensor, 74-75Metal-loaded polymer, 182

Chen, H. Y.Asynchronous Transfer Mode network, 124Commodity interconnects, 130

Chen, K. S. 93Chhabildas, L. C. 90Chiral, 147Choquette, K. D.

Composite resonator, 74Microsystems, 76Optoelectronics, 60Vertical-Cavity Surface-Emitting Laser array, 57Wafer fusion, 58

Chow, W. W.Composite resonator, 74Novel semiconductor devices, 10Optical sensor, 65Vertical-Cavity Surface-Emitting Laser array, 57

Christenson, T. R.Microelectromechanical Systems assembly, 97Micromagnet, 68

Christon, M. A. 44Chromatography, 136Chrzan, D. C. 12Chu, D. D. 142Circuit, 167Claassen, J. P. 138Clean-up (soil), 150Climate, 208Cluster

Atomic, 183Computing, 130

CMOSsee Complementary MetallicOxide Semiconductors

Coats, R. S. 38COBE

see Cosmic Background Radiation

Cochran, R. J. 34Coherence, 210Coil gun, 210-211Cold-Spray Processing, 24Cole, E. I., Jr.

Integrated Circuit interconnects, 167Microcode evaluation, 179

Coleman, P. D. 206Collective, 194-195Collector, 139Collins, E. W. 106Coltrin, M. E.

Multicomponent transport, 93Virtual reactor, 59

Column (capillary), 148Combustion, 153Complementary Metallic OxideSemiconductors, 160-161Comprehensive Test BanTreaty, 200Complex

Distributed systems, 194-195Flows, 84-85Imaging, 142-143Sample screening, 148

Compliant (substrates), 71Composite

Colloidal slurry, 25Interfacial reaction, 185Vertical-Cavity Surface-Emitting Laser, 74

CompressionEngine, 153Isentropic, 224Power, 218-219

Computer-Aided DesignFabrication, 98Immersive, 114Scanned data, 116

Concentrator (bioaerosol), 139Constraint (modeling), 40Contaminant

Adhesive bond, 100-101Environmental reconnaissance, 156

Microsystems, 78 Soil, 150Conversion (energy), 190Cooperative monitoring, 172Cordaro, J. T. 137Corrosion, 166

see also: DegradationCosmic Background Radiation, 178Coupled-resonator, 74Covert systems, 178-179CPlant (code)

Commodity interconnects, 130Fault tolerance, 129Scalable tools, 52

CrackFabrication, 180-181Finite element, 83Simulation, 42see also: Fracture

Index


Craft, R. L. 162Crawford, M. H.

Electronic defect, 73Materials engineering, 77Microdomain, 171Novel semiconductor devices, 10Wafer fusion, 58

Crosstalk, 57-58Crowder, S. V. 106Crowther, J. I., Jr. 210Cryptography, 179Crystal

Cadmium, 222Growth, 22Photonic, 9see also: Bicrystal

CSPsee Cold-Spray Processing

CTBTsee Comprehensive Test Ban Treaty

CTH (code)Architectural surety, 177Integrated service provisioning, 124

Cummings, E. B. 216Current, K. 61Curro, J. G.

Cleaning, 100Degradative materials, 148Hydrogenic materials, 41Polymer modeling, 184

DDaniels, J. W. 136Database (geometric), 123Data mining, 53

see also: Adaptive VisualizationDay, D. M.

Sparse eigensolver, 36Weapons of mass destruction, 223

Dean, L. B.High-speed networks, 126Nanosatellites, 198

De Boer, M. P.Microelectromechanical Systems, 102Micromachine reliability, 21

Dec, J. E. 150Decay, 190Decontamination, 199Deep-target, 138Defects

Chemistry, 28Cu-Al, 189III-Nitride electronics, 73

DegradationControlled, 148-149Stockpile, 160see also: Corrosion

Dehydrogenation, 152Denison, G. J. 156

DepositionCold-spray, 24Laser, 98-99Laser wire, 104Laser-Engineered Net Shaping, 180-181Thermionic materials, 214-215Ultra-hard, 12-13

De Sapio, V.Manufacturing, 102Streaming visualization, 107

Desiena, T. H. 179Desjardin, P. E. 88Desorption, 150Detection

Aqueous sensor, 154Bioaerosol, 139Biological weapons, 141Buried waste, 156High-priority analytes, 135Immunoaffinity, 136Massively parallel, 67Optoelectronic, 72Photo, 76Redox, 142Solvent, 182Soot, 92Targets, 140Volatile organic, 154

Devine, K. D.Density function theory, 36Modeling turbulent flows, 34

DiamondCoating, 12-13Sensor, 188-189

Diegert, C. F. 35Diegert, K. V. 46Diesel, 150-151Diffusion

Calculation, 184Gradient-driven, 33Materials growth, 22-23Model, 93Photonic, 202-203Vapor-phase, 81

Digital (video), 124Dike, J. J. 82Dimos, D. B. 16Diode

Pulsed power, 65Sensor, 62

Dison, H. L. 123Dispersion

Nanoparticle precipitation, 183Velocity, 90

Disruption (infrastructure), 164Dodd, P. E. 70Dohner, J. L. 171Dohrmann, C. R.

Finite-element meshing, 100Tetrahedral finite elements, 84

Index


Doped, 188Doran, L. M. 35Douglas, M. R. 201Downhole, 212

see also: HoleDownload (microcode), 179Doyle, B. L. 106Draelos, T. J. 130Draper, B. L. 62Dreeben, T. D. 89Drennen, T. E. 196Drill

Laser, 192-193Robot, 209Surface Area Modulation, 212

Dron, S. B. 206Drummond, T. J.

Materials engineering, 77Virtual reactor, 59

Dugger, M. T.Molecular-scale lubricants, 15Multilayer coatings, 12

Durant, J. L., Jr. 24Dyads, 221Dykhuizen, R. C. 24

EEaton, W. P. 159Echekki, T. 89Eichel, P. H. 142Eigensolution

Massively parallel, 38Multilevel substructuring, 235

Einfeld, W. 203EKP

see Electrokinetic PumpElasticity, 91Elbring, G. J. 138Electrical

Digital, 58Engine, 153Failure, 160-161Field, 14-15Fuel cell, 152-153Launcher, 210-211Photovoltaic module, 214Power generation, 190Power-grid, 211Property, 26-27Security, 168Simulation, 162-163Solar, 202-203see also: Piezoelectric

ElectrochemicalReaction, 93-94Redox, 232-233Spectroscopy, 154

ElectrodeDetector, 142Polymer biosensor, 232

Thermionic, 214-215Electroform

see LIGAElectrokinetic

Immunoaffinity sensors, 136Pump, 201

Electromigration, 160-161Electrophoresis, 216-217Electroplate, 216Electrospray, 191Elliptic, 44-45Emergent behavior, 47Emerging threat, 199Emerson, J. A. 100Emissions

Diesel, 150-151Hybrid drive train, 153Laser, 218-219Thermionic, 214-215

Emulsion, 150-151Encapsulant

Enzyme, 225Microelectromechanical Systems, 66Polymer modeling, 90Surface cleaning, 100-101Weapons systems, 166

Encryptionsee Cryptography

Encryptor, 126Energetic materials, 193Energy

Binding, 188Conversion, 190Hot-spot, 224Infrastructure, 164-165Kinetic, 210-211Micromagnet, 68-69Photosynthesis, 231Potential, 40Power system, 168Release, 200Short-pulse laser, 226Transition metal, 184Vehicle, 153

Engi, D. 196Enhanced Vapor Diffusion, 81Ensz, M. T.

Colloidal slurries, 25Laser wire deposition, 104

EnvironmentElectromagnetic imaging, 156Soil, 150Virtual, 125

EnzymeBiosensor, 225Redox, 232-233

EpitaxyCompliant substrate, 71Materials growth, 22-23Molecular beam, 58

Index


EpoxyConductive, 214Interfacial fracture, 18-19

Ergonomic, 118-119Espinoza, J. 128Etch

Dry, agile, 70Dry, large-area, 105Microoptic, 64Microsystems, 78Neutron-tube, 183

Ethernet, 130Evans, G. H. 93Evaporation

Electron, 214-215Self-assembly, 186

EVD,see Enhanced Vapor Diffusion

Ewsuk, K. G. 207Excimer, 106-107Excitation (fluorescence), 208Exciton

Gas, 188Wide bandgap, 10-11

Exfiltrate, 178Explosive

Attack, 177Material, 193Microchem lab, 172-173Monitoring, 200Spectral information, 227

Extraction, 154-155

FFAA

see Federal Aviation AdministrationFailure

Architectural, 177Complementary Metallic Oxide Semiconductors, 160-161Computer, 129Fracture prediction, 90-91Integrated circuits, 167Microelectromechanical Systems reliability, 159Modeling, 83Polymer modeling, 91System variability analysis, 162-163

Falcone, P. K. 203Fan, D. 52Fang, H. E. 42Faraday Rotation, 230Farino, A. J. 66Fatigue, 42-43Faulon, J. M. 43Fault, 129Feddema, J. T.

Distributed systems, 194Microelectromechanical Systems assembly, 97Video inspection, 103

Federal Aviation Administration, 191

Federico, P. J. 206Feeder, 98

see also: WireFeedstocks, 196-197Feibelman P. J.

Materials growth, 22Surface structure energies, 184

Fellerhoff, J. R.Interferometric Synthetic Aperture Radar, 210Terrain mapping, 138

FEsee Finite Element

FIBsee Focused Ion Beam

FiberLaser, 208Particle velocity, 228

Field Programmable Gate Array, 179Fighter (aircraft), 210-211Filaments, 226Filter

Digital, 70Image, 229

Filter, W. F. 160Finite Element

Automated substructuring, 235Laser ultrasonics, 82-83Meshing, 100Modeling localization phenomena, 83Modeling turbulent flows, 34-35Multilevel linear equation solvers, 233Polymer modeling, 91Powder pressing, 207Sparse eigensolver, 36Tetrahedral, 84Unstructured grid problems, 51see also: Mesh

FireSmoke environments, 165Soot, 92

Fireball, 200Fisk, L. A. 52Fleetwood, D. M. 62Fleming, J. G.

Materials engineering, 77Vacuum encapsulation, 66

Fleming, R. P. 179Flexural Plate-Wave

Sensor membrane devices, 226-227Surface micromachining, 16-17

Flip-chip, 64Flores, R. S. 70Floro, J. A.

Compliant substrates, 71Materials growth, 22

Flounders, A. W.Biological weapon detector, 142Polymer biosensor, 232

FlowsBioaerosol concentrator, 139Concentrated suspensions, 228-229

Index


Laser-spray fabrication, 98-99Lattice Boltzman, 84-85Microfluidic engineering, 201Microfluidics, 216-217Modeling turbulent, 34-35Radiative transport, 88-89Transient phenomena, 89Transport simulation, 212-213Virtual reactor, 59

Fluorescence, 216-217Focus

Cold-spray fabrication, 24Power compression, 218-219Synthetic Aperture Radar, 137

Focused Ion BeamIntegrated circuit interconnections, 167Microfabrication, 106-107

Foiles, S. M. 86Follstaedt, D. M.

Compliant substrates, 71Materials engineering, 77Multilayer coatings, 12Solar cells, 202Wafer fusion, 58

Ford, D. M. 33Fossum, A. F. 207FPGA

see Field Programmable Gate ArrayFPW

see Flexural Plate-WaveFracture

Predicting, 90-91Thermoset interface, 18-19see also: Crack

Framework, 162Fredrich, J. T. 84Freeforming, 25Frequency (electromagnetic), 156Friction

Lubricants, 15Reliability, 21

Friedman-Hill, E. J. 34Friedmann, T. A.

Diamond, 188Multilayer coatings, 12

Friesen, J. A.Integrated Asynchronous Transfer Mode service, 124Virtual desktop, 125

Frink, L. J. D. 36Fritz, I. J. 9Frye-Mason, G. C.

Chemical microsensors, 75Microchem lab, 172Sensing systems, 135

Fuel-cellsHydrogen production, 152Solid-oxide, 191

Fuel-injection, 150-151FUEGO (code), 37Fuerschbach, P. W. 27Funkhouser, D. R. 162

Fye, R. M.Computational materials, 42Hydrogenic materials, 41Phase field model, 52

GGAIA

see Global Approaches toInfrastructure Analysis

Gamma-ray, 222Garbin, H. D. 138Garcia, E. J. 61Gardner, T. J.

Catalytic sensor, 10Fuel cells, 152

Garino, T. J. 68Garrett, S. E. 214Gas

Cold-spray, 24Electron, 188Laser-spray, 98-99Soot, 92Vapor-phase diffusion, 81Velocity, 90-91

GateArrays, 179Optoelectronic, 72

Gaussian, 188Gear, 97Gee, J. M.

Nanosatellite, 198Photovoltaic modules, 214Solar cells, 202

Geib, K. M.Composite resonator, 74Microsystems, 76

Gentile, A. C. 52Gentry, S. M. 136Geology, 223Geometric databases, 123Geophysical, 138-139Geosphere, 212-213Gilliom, L. R. 194Gilmore, D. L. 24Gladwell, T. S.

Cooperative automation, 111Ergonomics, 118

Glass, S. J. 42Global Approaches to InfrastructureAnalysis, 196GLRS

see Grating Light ReflectionSpectroscopy

Godfrey, A. W. 86Goeke, R. S. 183Goldsborough, S. S. 153Goldsmith, S. Y.

Ballistic missiles, 204Distributed systems, 194System surety, 119

Index


GOMA (code)Electrochemical reactions, 93Unstructured grid, 51

Gonzales, R. A. 130Gourley, P. L. 9Grain (metal), 86Graphite, 41Grating Light Reflection Spectroscopy,

154Grid

Electromagnetic simulation, 38-39Multiscale simulation, 44Radiative transport, 88-89Unstructured, 51see also: Power

Griffith, M. L.Colloidal slurries, 25Laser-spray fabrication, 98Laser wire deposition, 104

Griffiths, S. K. 216Gritzo, L. A.

Radiative transport, 88Smoke environments, 165Soot, 92

Grotbeck, C. L. 179Ground-level, 138Ground

Environmental reconnaissance, 156Explosion monitoring, 200Sensors, 220

GSLIB (software)see Geosphere

Guess, T. R.Degradative materials, 148Polymer modeling, 91

Guns, 210-211Guthrie, S. E. 222

HHaaland, D. M. 148Hadley, G. R.

Optical sensor, 65Vertical-Cavity Surface-Emitting Laser arrays, 57

Half-life (boride), 190Hamilton, J. C.

Materials growth, 22Smart Interface Bonding Alloys, 17Simulation, 43

Hamilton, V. A. 130Hammons, B. E.

Composite resonator, 74Microsystems, 76Nanophotonics, 9

Han, J.Electronic defects, 73Materials engineering, 77Novel semiconductor devices, 10

Hard-coded tools, 52Hardness

Diamond, 188

Drilling, 209Nanocomposites, 186Surface, 183

Harmony, D. W. 142Haroldsen, B. L. 203Harrington, J. J. 180Harris, D. L.

Global Approaches to Infrastructure Analysis, 196Infrastructure interdependency, 164

Hart, W. E.Engineering optimization, 48Production planning, 108Scheduling optimization, 50

Harwell, L. D. 104Haynes, R. A. 38Heat-pipe, 66Heat transfer, 89Heavy-ion, 70-71Hebner, G. A. 105Heffelfinger, G. S. 33Heinstein, M. W. 84Heller, E. J.

Chemical microsensor, 75Robotic vehicle, 68

Helms, C. J. 58Henderson, C. L. 61Hendrickson, B. A. 53Henry, T. R. 123Hess, B. V. 216Heterogeneous materials, 90Heustess, J. E. 178Hicken, G. K. 107Hickerson, D. 114Hickox, C. E., Jr. 84Hiebert-Dodd, K. L. 196Hierarchical (wavelets), 44Hietala, S. L. 75Hietala, V. M.

Chemical microsensors, 75Photonic interconnects, 58

HIDRAsee High-Altitude Doppler RadarAltimeter

High-Altitude Doppler Radar Altimeter,138

High-aspect, 216High-explosive, 193High-level tools, 52High-Power Microwave, 206Hillaire, R. G. 107Hilton, N. R. 222Hinckley, M. K. 136HMX

see High-explosiveHo, C. K. 81Hobbs, D. J. 33Holcomb, D. J. 209Hole

Laser micromachining, 192-193Robot drilling, 209see also: Downhole

Index


Holland, K. G. 228Hollowell, J. A. 137Holm, E. A.

Computational materials, 42Materials microstructures, 229Recrystallization of metals, 86

Hopkins, P. L. 212Horn, K. M.

Nanostructures, 20Virtual reactor, 59

Horstemeyer, M. F. 43Hosking, F. M. 64Hot-press, 68-69Hot-spot, 224Hough, P. D. 129Houston, J. E.

Molecular-scale lubricants, 15Smart Interface Bonding Alloys, 17

HPMsee High-Power Microwave

Hruby, J. M. 216HSI

see Hyperspectral ImagingHu, T. C. 130Hughes, D. A.

Modeling localization phenomena, 83Recrystallization of metals, 86

Hughes, R. C.Biological weapon detector, 156Catalytic sensors, 10Chemiresistors, 182Microtelemetry, 74

Human (adaptive sensing), 149Hunter, K. O. 48Hurd, A. J. 228Hurtado, J. E. 47Hutchinson, R. L.

High-speed networks, 126System surety, 119

Hwang, R. Q.Metal-oxide surfaces, 28Smart Interface Bonding Alloys, 17

Hwang, Y. K. 123Hybrid (engine), 153Hydrogen production, 152Hydrogenic, 41Hydrophilic, 218Hydrophobic

Nanocomposites, 186Self-assembling macrosystems, 218

Hyperbolic, 44Hyperspectral, 179Hyperspectral Imaging, 136-137

IIcosahedral, 190IC

see Integrated Circuit

IDESsee Infrastructure for DistributedEnterprise Simulations

ImagerElectromagnetic, 156Electron micrograph, 229Geometric model builder, 35Microfluidics, 216-217Video, 103see also: Scanning-Tunneling Microscopy, SyntheticAperture Radar, Information-Efficient Spectral ImagingSystem, Optically Recording Velocity InterferometerSystem

Immersive (Computer Aided Design), 114Immunoaffinity, 136Immunoassay, 225Impact-loading, 90Implants, 183Implosion, 224Impurities, 12Inclusion, 91Index (databases), 123Information-Efficient Spectral ImagingSystem, 136Infrasound, 200Infrastructure

Architectural surety, 177Global Approaches to Infrastructure Analysis, 196Power, 168Simulation, 162

Infrastructure for DistributedEnterprise Simulations

Fault tolerance, 129System questions, 113

Ingersoll, D. 198Initiation (explosive), 193Injection (engine), 150-151Inspection (video), 103Instability (radiation), 201Insulator

Nonvolatile memory, 62Optoelectronics, 60

Integrated CircuitComplementary Metallic Oxide Semiconductors, 160-161Interconnections, 167

Internal combustion, 153Ion-beam, 70-71Ion-exchange

Catalytic sensor, 10Fuel cells, 152

Ion-mobilityBiological materials, 191Explosives, 227

Ionophore, 154-155Irwin, L. W.

Complementary Metallic Oxide Semiconductors, 160Microelectromechanical Systems reliability, 159

Isentropic, 224

Index


ISISsee Information-Efficient SpectralImaging System

Islands (materials growth), 22Isothermal, 160-161Isotope

Boride, 190Detectors, 222Z-pinch, 224

Istrail, S.Biological weapon detection, 141Self-assembling macrosystems, 218

JJackson, N. B. 196Jacobian, 36-37Jacobs, J. A. 199Jakowatz, C. V., Jr. 137Jamison, G. M. 26Janek, R. P.

Biological weapon detector, 142Polymer biosensor, 232

Janssen, C. L. 40Janus, 218Jefferson, K. J. 179Jennison, D. R.

Quantum dot arrays, 26Metal-oxide surfaces, 28Nanostructures, 20

Johnsen, H. A. 92Johnson, A. J. 106Johnson. D. K. 53Johnson, M. M.

Enterprise simulation, 113Fault tolerance, 129

Johnston, A.M. 130Jones, D. A.

Production planning, 108Scheduling optimization, 50

Jones, E. D.Broadening mechanism, 188Nanophotonics, 9Novel semiconductor devices, 10

Jortner, J. N. 125Jung, J. 100

KKasunic, K. J. 154Keck, J. D. 99Keefe, R. G. 212Kegelmeyer, W. P. 131Kellogg, G. L. 22Kelly, M. J. 154Kemme, S. A. 154Kempka, S. N. 235Kent, M. S. 18Kern, J. P. 198Kerstein, A. R.

Modeling turbulent flows, 34Transient phenomena, 89

Key, S. W. 84Kiefer, M. L. 38Kinematic, 118-119King, C. 102King, D. B. 214King, R. K. 204Kjeldgaard, E. A. 50Klarer, P. R. 171Klein, P. A. 90Klem, J. F.

Compliant substrates, 71Nanophotonics, 9Optoelectronics, 60Solar cells, 202Virtual reactor, 59

Kliner, D. A. 208Knapp, J. A.

Micromachine reliability, 21Multilayer coatings, 12

Knorovsky, G. A. 42Knowledge mining, 53Koch, M. W. 140Koller, M. H. 53Kottenstette, R. J.

Chemical microsensors, 75Sensing systems, 135

Kozlowski, D. M. 102Kravitz, S. H.

Bioaerosol concentrator, 139Biological weapon detector, 142Microchem lab, 172Micro-heat-pipe, 66Microsystems, 78Wafer fusion, 58

Krumel, L. J. 136

LLADAR

see Laser RadarLadd, M. D. 138Lafarge, R. A.

Geometric databases, 123Intermittent contacts, 49

Lagrangian, 88-89Laguna, G. A. 114LAMA

see Laser MapperLaminated (nanocomposites), 186LAMMPS

see Large-Scale Atomic/Molecular Massively ParallelSimulatorLandmine detection, 172-173Lanes, K. R. 179Large-Scale Atomic/Molecular MassivelyParallel Simulator, 40Larson, R. S. 93Larson, W. L. 160Laser

Biodetection, 203Communications, 220-221

Index


Diode, 62Flared, 65Mapper, 180Microfabrication, 106-107Micromachining, 192-193Nanosatellites, 198-199Nonflared, 65Optoelectronics, 72Plasma channels, 218Ultrasonics, 82-83Welding, 27WireFeed, 104Z-pinch, 224 Z-pinch diagnostics, 230-231see also: Vertical-Cavity Surface-Emitting Lasers

Laser Mapper, 180Laser Radar, 226Lattice Boltzmann, 84-85Launcher, 210-211Lavigne, G. F. 192Leaky, 57Lee, E. Y. 222Lee, S. R.

Compliant substrates, 71Lateral composition, 234Materials engineering, 77Novel semiconductor devices, 10Solar cells, 202

Lemen, E. K. 113Leonard, C. M., Jr. 107Leung, K. 45Leung, V. J. 100Lewis, C. L.

Intelligent agents, 171Intermittent contacts, 49

Lewis, P. R. 135LIGA (lithography, electroforming, molding)

Microelectromechanical Systems, 97Microfabrication, 106-107Micromachining, 216

Light-absorbing, 187Light-antennae, 231Lin, S. Y.

Nanophotonics, 9Optoelectronics, 72

Lindgren, E. R. 36Link, H. E. 194Liquid-membrane, 154-155Lithography, 69Little, C. Q.

3-D sensing, 149Cloud to Computer Aided Design, 116Immersive Computer Aided Design, 114Unattended monitoring, 180Video inspection, 103

Lo, C. S. 91Load-balancing, 38-39Lockwood, S. J. 99Loehman, R. E. 185Lopez, E. P. 100

Loubriel, G. M.Collective intelligence, 220Emerging threats, 199Environmental reconnaissance, 156

Loy, D. A.Degradative materials, 148Intelligent polymers, 26

Lu, W. 82Lubricant (micromachine), 15Ludowise, P. D. 92Lund, J. C. 222Lyo, S. K.

Nanophotonics, 9Optoelectronics, 72

MMacCallum, D. O. 104Macromolecule, 33Macrosystems, 218Magnet

see MicromagnetMah, B. A. 128Mansure, A. J. 212Manufacture

Automated, 138Cleaning, 130-131Interferometric Synthetic Aperture Radar, 210Laser Mapper, 180Low-volume, 106Parallel mechanism, 102Photovoltaic modules, 214Powder pressing, 207Semiconductors, 70

Mar, A. 65Marder, B. M. 210Marlman, K. S. 106Marozas, D. C. 164Martin, J. E. 26Martin, M. F. 106Martinez, L. G., Jr. 128Martinez, M. J. 212Martino, A.

Ionophores, 154Nanoseparation, 19

Marx, K. D. 162Mask

Membrane devices, 226-227Micromachining, 216Neutron-tube, 183

Massively Parallel Processing, 126-127Matalucci, R. V. 167Mayer, T. M.

Micromachine reliability, 21Molecular-scale lubricants, 15Nanometer-scale fabrication, 14

Mazarakis, M. G. 209MBE

see Molecular Beam EpitaxyMcCarty, K. F. 12McDonald, M. J. 112

Index


McWhorter, P. J. 15Medlin, D. L. 12Meirans, L. 123Melius, C. F.

Material aging, 34Parallel computational chemistry, 40

MeshComputational materials, 42Global minimization, 100Modeling localization phenomena, 83Multiscale simulation, 44Tetrahedral finite elements, 84Unstructured grid problems, 51see also: Finite Element

Metal-loaded, 182Metalorganic Chemical Vapor Deposition

Chemical sensors, 62Electronic defects, 73Materials engineering, 77Virtual reactor, 59

Metal-oxide, 28Meteorite, 200Meyers, C. E. 1Micelles, 186Michalske, T. A.

Microdomain, 171Molecular-scale lubricants, 15

Microchannels, 216-217Microchem, 172Microdomain, 171Microencapsulate, 205Microfluidic

Applied, 216-217Engineering, 201

Micro-heat-pipe, 66Microhole, 209Micromachine

Molecular-scale lubricants, 15Reliability, 21

MicromachiningFlexural plate-wave, 16-17Laser, 192-193LIGA, 216Microelectromechanical Systems, 61Microfabrication, 106-107Reliability tools, 159

Micromagnet, 68Micromechanics

Failure analysis, 91Materials simulations, 42

Microminiature, 171Microoptics, 64Microporous, 152Microsensor

Integrated chemical, 75Robotic vehicle, 68Solvent detection, 182

Microsimulation, 164Microsystem

Post-processed, 78Vertical-Cavity Surface-Emitting Laser, 76

Microtelemetry, 74Microtools, 106-107Miles, P. C. 150Mill, 106-107Miller, J. C. 193Miller, J. E.

Ionophores, 154Oxidative dehydrogenation, 196

Miller, P. A. 105Miller, S. L.

Molecular-scale lubricants, 15Visualization tools, 192

MiniatureBioaerosol concentrator, 139Robotic vehicle, 68

Miningsee Data mining

Miodownik, M. A. 86Missert, N. A.

Corrosion, 189Multilayer coatings, 12

Missile, 204Mitchell, E. A. 114Mix, L. P., Jr. 38MNA

see Monitored Natural AttenuationMOCVD

see Metalorganic Chemical VaporDeposition

Modine, N. A. 45Moen, C. D. 51Moffat, H. K. 59Mold, 68-69Molecular Beam Epitaxy, 59Monitor

Atmospheric explosion, 200Deep targets, 138Remote, 220Unattended, 180

Monitored Natural Attenuation, 150Monolayer, 15Monolithic

Microsystems, 76Nanoseparation, 19

Monomer, 186Montague, S. 66Montoya, T. V. 99Moody, N. R.

Modeling localization phenomena, 83Smart Interface Bonding Alloys, 17

Moore, R. H. 99Morales, A. M. 216Morgan, W. P. 214Mosher, D. A .83Motion

Ergonomics, 118-119Human, 102Targets, 137

Motor, 68-69Movie, 112-113Moving Target Indicator, 137

Index


Moya, M. M. 140Moyer, R. D. 178MPP

see Massively Parallel ProcessingMPSalsa (code)

Turbulent flows, 20-21Unstructured grid, 37

MTIsee Moving Target Indicator

Multilayer (coatings), 12Multiplex, 92Murray, J. R. 62Myers, S. M., Jr.

Electronic defects, 73Surface hardening, 183

NNanocluster, 26-27Nanocomposite, 186Nanodevice, 26Nanoengineered, 189Nanofabrication, 14Nanoparticle, 183Nanophotonics, 9Nanosatellite, 198-199Nanoseparation, 19Nanostructure

Fabrication, 14Recognizing atoms, 20

Nanotubes, 41Napolitano, L. M. 193Navigating, see Data miningNeilsen, M. K. 42Neiser, R. A., Jr. 24Nelson, C. L.

3-D sensing, 149Unattended monitoring, 180

Nelson, J. S. 20Nenoff, T. M. 149Net-shape, 98-99Network

Commodity interconnects, 130Surety, 128

Neural network, 227Neutron-tube, 183Nevers, J. A. 76Newman, G. A. 223Neyer, D. W.

Capillary array analysis, 148Chemical sensors, 136

Ngujo, M. A. 126Nicolette, V. F. 165Nilsen, V. 89Nilson, R. H. 216Noble, D. R. 84Nonproliferation, 172Nowlen, S. P. 165Nucleation, 86

OOberkampf, W. L. 46O’Connor, R. M. 84Olson, C. L. 199Optical

Channeling, 218-219Smoke, 165see also: Photonic

Optically Recording VelocityInterferometer System, 90Optoelectronics

Free-space microoptics, 64Quantum-well, 72

Ordination, 53Organophosphate, 232Orthogonal

Motion, 102Wavelets, 44

ORVISsee Optically Recording VelocityInterferometer System

Osbourn, G. C.Distributed systems, 194Microdomain, 171Nanostructures, 20Sensing systems, 135

Oscillator, 75Ottesen, D. K. 92Oxidative, 196-197Oxides

Complementary Metallic Oxide Semiconductors, 160-161Nonvolatile memory, 62-63Thermionic material, 214-215

PPaez, T. L. 88Palmer, D. W. 124Paradiso, N. J., Jr. 153Parmeter, J. E. 227Partnership for a NewGeneration Vehicle, 150Pasik, M. F. 38Pate, R. C. 206Patterson, P. E. 206Paul, P. H.

Microfluidic engineering, 201Microfluidic science, 216

Peace, G. L. 156PEM,

see Plastic-EncapsulatedMicroelectronics

Peña, E. A. 114Peña, J. G. 126Penetrate

Drilling robot, 209Environmental reconnaissance, 156

Peng, L. W. 82

Index


Peters, R. R.Automatic assembly planning, 114Ergonomics, 118

Peterson, D. W. 166Peterson, K. A. 159PFM

see Phase Field ModelPhase Field Model, 52-53Philips, C. A.

Optimization engineering, 48Production planning, 108Scheduling optimization, 50

Phillips, L. R. 194Photodetector, 76Photonic

Biophotonic, 187Interconnects, 58-59Nanophotonics, 9Solar cells, 202see also: Optical

Photosynthesis, 231Photovoltaic, 214Pierson, L. G.

Asynchronous Transfer Mode encryption, 126Nanosatellites, 198Photonic interconnects, 58

Piezoceramic, 230-231Piezoelectrics

Chemical microsensors, 75Flexural plate-wave, 16-17see also: Electrical

Pigment, 231Plantenga, T. D.

Computational chemistry, 40Enterprise simulations, 113

PlasmaDry etching, 70Large-scale, dry processes, 105Power compression, 218-219Rayleigh-Taylor mitigation, 201Simulation software, 38Wire-array Z-pinch, 230

Plastic-Encapsulated Microelectronics,166

Plate-wave, 16PLD

see Pulsed-Laser DepositionPlimpton, S. J.

Computational chemistry, 40Electromagnetic simulation, 38Electronic structure codes, 45Phase field model, 52Programming paradigms, 50Smart Interface Bonding Alloys, 17

Plymale, D. L.Manufacturing, 102Microfabrication, 106

PNGVsee Partnership for a New GenerationVehicle

Poco, 182

Polosky, M. A. 97Polymeric, 148-149Portable (sensor), 136Portal detector, 191Post-processed, 78Power

Reliability, 211Security, 168

Prast, T. L. 216Probe, 14Projectiles, 210-211PRONTO3D (code), 177Propagation, 218-219Protein

Chemical sensors, 136Novel biosensor, 232-233

Proton, 62-63Provencio, P. N.

Multilayer coatings, 12Quantum dot arrays, 26

Pryor, R. J.Distributed systems, 194Infrastructure interdependency, 164Intelligent agents, 47

PulsedAccelerator, 199Filament laser, 226Ground-penetrating radar, 156Micromachining, 192Optical sensor, 65Power compression, 218Z-pinch, 230

Pulsed-Laser Deposition, 12Pumped

Bioaerosol concentrator, 139Microfluidic engineering, 201

QQuantum

Dot arrays, 26Hydrogenic materials, 41Materials aging, 34Optoelectronics, 72Solar cells, 202-203see also: Vertical-Cavity Surface-Emitting Laser

QUICKSILVER (code), 39

RRadar, 137

see also: Synthetic Aperture RadarRader, D. J. 139Radiation-hardened, 62-63Radiation

Advanced sources, 201Background Radiation Anisotropy MeasurementSensor, 178Detectors, 222Emerging threats, 199Icosahedral borides, 190Microsystems, 76

Index


Radioisotopessee Isotope

Radionuclide, 150Rail (gun), 214-215Rakestraw, D. J. 172Range-image, 35Rayleigh-Taylor, 201Ray, L. P. 123RCPD,

see Resonant-Cavity PhotodetectorsReconnaissance, 156Recycling, 142Red-Horse, J. R.

Automated substructuring, 235Linear equation solvers, 233Nondeterministic modeling, 88

Redmond, J. M. 21Reed, K. W. 21Reedy, E. D., Jr.

Cleaning, 100Fracture analysis, 18Polymer modeling, 91

Reese, G. M. 36Reeves, P. C. 212Remote

Collective intelligence, 220-221Intelligence, 178-179Sensing, 218-219Unattended monitoring, 180

Renlund, A. M. 193Reno, J. L.

Chemical microsensors, 75Optoelectronics, 72

Renzi, R. F. 139Reproducing Kernel Particle Method, 44Resistor, 67Resonant-Cavity Photodetectors, 76Resonator

Chemical microsensors, 76Composite, 74

Ricco, A. J.Biological weapon detector, 142Chemical sensors, 62Nanometer-scale fabrication, 14Organic detection, 67

Rieger, D. J. 105Riesen, R. E. 50Riley, D. J.

Electromagnetic simulation, 38High-power microwave, 206

Rinehart, L. F. 206Ring

Laser, 65Polymer, 41

Rintoul, M. D. 42Risk, 162

see also: SuretyRivord, G. E. 119RKPM,

see Reproducing Kernel ParticleMethod

Roach, D. W. 44Robertson, P. J.

Asynchronous Transfer Mode encryption, 126Asynchronous Transfer Mode integrated service, 124Photonic interconnects, 58

Robino, C. V. 66Robinson, A. C. 51Robinson, D. G.

Atmospheric corrosion, 168Nondeterministic modeling, 88Power reliability, 211Power security, 168Stockpile aging, 160

Robot3-D sensing, 149Collective intelligence, 220-221Cooperative automation, 111Distributed systems, 194-195Drilling, 209Intelligent agents, 171Microelectromechanical Systems assembly, 97Miniature vehicle, 68

Rodacy, P. J. 191Rodgers, M. S,

Microelectromechanical Systems prototyping, 61Standard cell, 102

Roe, D. C.Biological weapons detection, 141Chem/bio terrorism, 203

Romero, V. J.Nondeterministic modeling, 88Simulation optimization, 94

Rondeau, D. M. 210Ross, J. R. 92Rotation

Virtual reactor, 59Z-pinch, 230

Ruby, D. S. 105Ruffner, J. A.

Flexural plate-wave, 16Metal-oxide surfaces, 28Thermionic materials, 214

Rupley, F. M. 93Rutherford, B. M.

Modeling uncertainties, 48Simulation optimization, 94

Ryba, G. N. 172

SSackos, J. T. 35Salazar, J. S. 140Salinger, A. G.

Density-function theory, 36Modeling turbulent flows, 34

Salmi, A. J. 216SAM

see Surface Area ModulationSands, D. N. 38SAR

see Synthetic Aperture Radar

Index


Sarfaty, R. A. 119Sasaki, D. Y. 135Satellite

Global monitoring, 200Intelligence, 178Nanosatellite, 198

Sault, A. G.Catalytic sensors, 10Fuel cells, 152Metal-oxide surfaces, 28Oxidative dehydrogenation, 196

Saunders, R. S.Degradative materials, 148Intelligent polymers, 26

SAW,see Surface Acoustic Wave

Scanning-Tunneling MicroscopyLateral composition, 234Metal-oxide surfaces, 28Materials growth, 24Nanometer-scale fabrication, 14Nanostructures, 20

Schimmel, W. P. 210Schlienger, M. E.

Direct fabrication, 180Laser-spray fabrication, 98

Schmidt, R. C.Modeling turbulent flows, 34Transient phenomena, 89

Schmitt, D. J.3-D sensing, 149Colloidal slurries, 25Cooperative automation, 111Parallel manufacturing, 102

Schmitt, R. G. 203Schneider, L. X. 210Schoeneman, J. L. 198Schoeniger, J. S.

Bioaffinity array, 142Biological weapon detection, 141Capillary array analysis, 148Chemical sensors, 136Covert biosensors, 225

Schriner, H. K. 61Schubert, W. K.

Flexural plate-wave, 16Membrane devices, 226Microsystems, 78

Schultz, P. A. 45Schunk, P. R. 51Schwank, J. R. 62Schwegel, J. 125Scofield, T. W. 99Scott, S. H. 148Seager, C. H. 73Sears, M. P.

Electronic structure codes, 45Nanostructures, 20Programming paradigms, 50

Seidel, D. B. 38Seidl, E. T. 34

Self-assembledNanocomposites, 186Photosynthesis, 231Simulation, 218

Self-focusing (laser), 218-219Self-healing (boride), 190Self-stabilizing, 218-219Sellinger, A. 135Semiconductor

Dry etching, 70Filament lasers, 226Icosahedral borides, 190Novel devices, 10Optoelectronics, 72Solar cells, 202-203Virtual reactor, 59Wafer fusion, 58

SensorAdaptive 3-D sensing, 149Background Radiation Anisotropy MeasurementSensor, 178Catalytic membrane, 10Chemical (integrated), 75Chemiresistors, 182Chiral, 147Collective intelligence, 220Cooperative automation, 111Cadmium Zinc Telluride, 222Diamond, 188-189Intelligent agents, 171Information-Efficient Spectral Imaging System, 136-137Laser-spray, 98-99Microelectromechanical Systems , 66Microtelemetry, 74-75Midwave-infrared, 62Model builder, 35Optical, 65Robotic, 68Stand-off, 205Unattended monitoring, 180Volatile organic, 67see also: Biosensor, Detection,

SEUsee Single-Event Upset

Sexton, F. W. 70Shaddix, C. R.

Smoke environments, 165Soot, 92

Shadid, J. N.Modeling turbulent flows, 34Unstructured grid problems, 51

Shaneyfelt, M. R. 62Shared-Memory Processing, 50-51Shea, L. E. 58Sheaffer, D. A., Jr. 107Shelnutt, J. A.

Artificial photosynthesis, 231Biophotonics, 187Chiral sensors, 147Intelligent polymers, 26

Index


Ionophores, 154Shepodd, T. J. 19Shield, 190Shinn, N. D. 17Shock-waves, 228Sholander, P. E. 128Shope, S. L.

Electric launcher, 210Emerging threats, 199

Short-Period Superlattice, 234Shul, R. J.

Electronic defects, 73Integrated microsystems, 78Materials engineering, 77

Siebers, D. L. 150Siegal, M. D. 150Sieving, 41Signal

Asynchronous Transfer Mode, 124Chemiresistors, 182Collective intelligence, 220-221Complementary Metallic Oxide Semiconductors, 160-161Distribution, 58-59Geophysical networks, 138-139Particle velocity, 228Surface Area Modulation telemetry, 212

Silva, B. L 105Simmermacher, T. W.

100-year-life, 233Wind turbines, 230

Simmons, J. A. 72Simonson, K. M. 142Simonson, R. J. 225Singh, A. K. 225Single-Event Upset, 70-71Sinter

Micromagnets, 68Self-assembling macrosystems, 218

Sipola, D. L. 99Sleefe, G. E. 138Slurry

Colloidal, 25Fuel cells, 191

Slutz, S. A. 224Small, D. E.

3-D sensing, 149Unattended monitoring, 180

Smith, A. V. 60Smith, D. A. 136Smith J. H.

Flexural plate-wave, 16Microelectromechanical Systems, 192Microoptics, 64

Smithberger, G. L. 179Smoke (environments), 165SMP

see Shared-Memory ProcessingSmugeresky, J. E. 98Sniegowski, J. J.

Microelectromechanical Systems prototyping, 61

Micromachine reliability, 21Molecular-scale lubricants, 15Vacuum encapsulation, 66

SOFCsee Solid-Oxide Fuel Cell

SoilEnvironmental reconnaissance, 156Radionuclide desorption, 150

Solar-cellDry processes, 105Nanosatellites, 198-199Novel material, 202-203Photovoltaic modules, 214

SolderMicrooptics, 64Photovoltaic modules, 214

Solid-modelAnalysis tools, 117Immersive Computer Aided Design, 114

Solid-Oxide Fuel Cell, 191Soliton, 218Somerday, B. P. 222SONET

see Synchronous Optical NetworkSorensen, N. R. 166Spahn, O. B.

Microoptics, 64Optoelectronics, 60

Spectroelectrochemicalsee Electrochemical

SpectroscopyAnalysis tools, 117Organic sensor, 154Ion mobility, 191

Spielman, R. B.Faraday rotation, 230Isentropic compression, 224Rayleigh-Taylor mitigation, 201

Spill (detection), 182Spires, S. V.

Distributed systems, 194System surety, 119

Spletzer, B. L.Distributed systems, 194Emergent behavior, 47Intelligent agents, 171

Spooner, J. T. 106Spray

Cold-spray, 24Laser, 98Laser-Engineered Net Shaping, 180-181

Sprytron, 182SPS

see Short-Period SuperlatticeStallard, B. R. 136Stans, L. 130Stantz, K. M. 220Staple, B. D. 66Staton, A. W. 67Stechel, E. B. 45Stereology, 229

Index


Stevens, M. J.Fracture analysis, 18Molecular-scale lubricants, 15

Stewardshipsee Stockpile

STMsee Scanning-Tunneling Microscopy

Stockman, H. W. 84Stockpile

Aging simulation, 43Enterprise simulations, 113Production planning, 108Reliability, 160

Stone, C. M. 84Streaming, 107Strickland, J. H. 88Sturtevant, J. E. 38Sullivan, C. T.

Ballistic missiles, 204Nanosatellite, 198Optoelectronics, 60

Sullivan, J. P.Corrosion, 189Diamond, 188Optoelectronics, 60

Supercomputer, 34Superlattice, 234Surety

Asynchronous Transfer Mode, 128Information systems, 123Life-cycle, 119see also: Architecture, Risk

Surface Acoustic WaveFlexural plate-wave, 16Integrated microsensors, 75Microdomain, 171Sensor arrays, 67

Surface Area Modulation, 212Supramolecular, 186Surfactant

Fuel cells, 152Materials growth, 22

Swanson, B. E. 210Swartzentruber, B. S.

Materials growth, 22Metal-oxide surfaces, 28Nanometric fabrication, 14

Sweatt, W. C.Information-Efficient Spectral Imaging System, 136Organic sensors, 154

Sweet, J. N. 166Swiler, L. P. 88Synchronous Optical Network

Asynchronous Transfer Mode encryption, 126High-speed network, 126-127

Synchrotron, 216Synthetic Aperture Radar

Automatic Target Recognition, 142-143Interferometric Synthetic Aperture Radar, 210Moving targets, 137Obscured targets, 140

TTag (microtelemetry), 74Tan, M. X.

Bioaerosol concentrator, 139LIGA, 216Microelectromechanical Systems, 97

Tanaka, T. J. 165Tangyunyong, P.

Integrated Circuit interconnections, 167Microelectromechanical Systems, 159

Tanner, D. M. 159Tappan, A. S. 193Tarbell, W. W. 204Target

Automatic Recognition, 142-143High-power microwave, 206-207Imagining, 90Recognizing, 140Synthetic Aperture Radar, 137see also: Deep-Target

Tarman, T. D.Asynchronous Transfer Mode encryption, 126Commodity interconnects, 130

TDLsee Tunable Diode Laser

Telecommunication, 164-165Teraflop, 45Terrorism

Chemical/biological, 203Emerging threats, 199

Thacher, P. D. 178Thermal-battery, 93Thermionic, 214-215Thermometric, 178Thermoset, 18Thomas, D. H. 136Thomas, E. V. 130Thomas, G. A. 203Thompson, A. P. 33Thompson, B. M. 162Thorne, L. R. 92Tigges, C. P. 59Tikare, V.

Laser wire deposition, 104Phase field model, 52Self-assembling macrosystems, 218

Time-Resolved Ion-Beam–InducedCharge Collection, 70-71Tips (Scanning-Tunneling Microscopy), 20-21Tissue (engineering), 235Tolendino, L. F. 128Tong, C. H.

Fault tolerance, 129Materials aging, 40Unstructured grid problems, 51

Topography (atomic), 20Topological, 114Toth, R. P. 205Toxin, 136Trajectory, 200

Index


Trahan, M. W. 220Transducer

Flexural plate-wave, 16Membrane devices, 226-227

Translator, 112Transmitter

Environmental reconnaissance, 156Surface Area Modulation telemetry, 212

TRIBICCsee Time-Resolved Ion-Beam–Induced ChargeCollection

Trinkle, J. C.Ergonomics, 118Life-cycle assembly, 114

Trott, W. M. 90Trucano, T. G. 94Tsang, R. P. 124Tsao, J. Y. 71Tuminaro, R. S.

Sparse eigensolver, 36Unstructured grid problems, 51

Tunable Diode Laser, 92Turbine, 230-231Turbulence (modeling), 89Turman, B. N. 199Tuttle, B. A.

Flexural plate-wave, 16Neutron generators, 99

UUlibarri, T. A. 148Ultrasonic, 82-83Unstructured-grid, 38-39UTOPIA (code), 126-127

VVacuum (encapsulation), 66Van Blarigan, P. 153Vandernoot, V. A. 136Vandewart, R. L. 162Van Leeuwen, B. P. 128Van Swol, F. B. 41Vapor

Biosensor, 232-233Diffusion, 81Spill detection, 182

Vawter, G. A.Dry etching, 70Microoptics, 64Optical sensor, 65Optoelectronics, 60

VCSELsee Vertical-Cavity Surface-Emitting Laser

Vedula, V. R. 42Vegetation, 138Velocity Interferometer System for AnyReflector

Heterogeneous materials, 90Picosecond measurements, 228

Venturini, E. L. 68Vertical-Cavity Surface-Emitting Laser

High-power, 57Wafer fusion, 58Selective oxidation, 60-61Composite-resonator, 74Microsystems, 76see also: Laser, Quantum

Very Low Frequency, 223Vibrations (wind turbine blade), 230-231Video

Asynchronous Transfer Mode, 124-125Explosion monitoring, 200Inspection, 103

VirtualDesktop, 125Microelectromechanical Systems, 192Reactor, 59

Virus (biological), 191VISAR

see Velocity Interferometer Systemfor Any Reflector

Visualization, 192VLF

see Very Low FrequencyVOC

see Volatile Organic CompoundsVoigt, J. A. 99Volatile Organic Compounds

Detection, 67Robotic vehicles, 68

Volponi, J. V. 136VOLMAX (code), 24-25Vortex, 88-89Voth, T. E. 44VxInsight, 53

WWafer, 58Wagner, J. F. 199Wagner, J. S.

Collective intelligence, 220Engineering optimization, 48

Walker, T. R. 107Walkup, J. W. 179Wally, K.

Bioaerosol concentrator, 139Biological weapons detector, 142Polymer biosensor, 232

Walsh, D. S.Solar cells, 202Time-Resolved Ion-Beam–Induced Charge Collection,70

Warren, M. E.Microoptics, 64Microsystems, 76Microdomain, 171Nanoseparation, 19Photonic interconnects, 58

Warren, W. L. 62

Index


Watterberg, P. A. 117Wave

Chemical sensors, 62Flexural plate-wave, 16-17Laser ultrasonics, 82-83Microchem lab, 172-173Optical sensor, 65Optoelectronics, 72Wavelet, 44-45see also: Surface Acoustic Wave

Webb, S. W. 81Weber, T. M. 171Wehlburg, J. C.

Emerging threats, 199Image analysis, 179

Weinbrecht, E. A. 210Weld

Laser arc welding, 27Laser wire deposition, 104

Wellman, G. W. 42Wendt, J. R.

Microoptics, 64Nanophotonics, 9Optoelectronics, 72

Wessendorf, K. O. 78Wheeler, D. R.

Degradative materials, 148Intelligent polymers, 26

Wide-bandgap, 10Wilcoxon, J. P. 26Williams, A. B. 51Williams, J. S. 179Wire

Array, 230Laser deposition, 104see also: Feeder

Witkowski, W. R. 100Witzke, E. L. 126Wolfer, W. 171Womble, D. E. 44Wong, C. C. 171Woodworth, J. R. 70World Wide Web

Multimedia documentation, 112-113Streaming visualization, 107

Wright, A. F.Electronic defects, 73Novel semiconductor devices, 10Structure codes, 45

Wright, S. A. 172Wu, J. 153Wu, K. L. 153Wunsch, S. E. 89Wyckoff, P. S. 130Wylie, B. N. 53Wyss, G. D. 162

XXavier, P. G.

Cloud to Computer Aided Design, 116

Geometric databases, 123Intelligent agents, 171

YYang, P.

Dry processes, 105Microfabrication, 106

Yarberry, V. R.Microelectromechanical Systems, 102Visualization tools, 192

Yazzie, S. H. 160Yee, A. A. 138Yee, M. L. 138Yelton, W. G. 67Yocky, D. A. 140Yoshimura, A. S. 113Young, W. F. 119

ZZanini, D. V. 153Zavadil, K. R. 214Zhang, P. 150Z-pinches

Faraday rotation, 230Isentropic compression, 224Rayleigh-Taylor mitigation, 201

Zutavern, F. J.Filament laser, 226Optical sensor, 65

E N D O FD O C U M E N T


Documents

LDRD Annual ReportTable of Contents iv Sandia National Laboratories/LDRD FY 1998 Annual Report 43 From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment 44 An Investigation