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Nanosciences @Indian Institute of Technology Kanpur
Nano-Science & Technology InitiativeDepartment of Science and Technology, India
Ashutosh SharmaDepartment of Chemical Engineering
DST Unit on Nanosciences @ IITK
Mesoscale Structures, Patterning and Properties with Emphasis on Soft Materials and Thin Films
A state-of-the-art facility and resources for soft matter nanoscience and nanotechnology.
Explore new techniques of nano-fabrication based on a creative combination of “top-down” including soft lithography, self-assembly and self-organization.
Projects related to nano-scale understanding, fabrication and use of soft materials in coatings, NEMS, functional interfaces and bulk-nano
Journey of the last two years!
Nano-Sciences at IITK: A Mega-Passion…….
Self-assembly
Micro- and Nano Fabtructure Property Behavior
Lithographies, Beams…
op-own
Bottom-up
Self-organization
Highly Multidisciplinary AND Interdisciplinary TeamCORE GROUP FACULTY (~ 10)
Ashutosh Sharma (soft nano fabrication; nanomechanics)Ramesh C. Budhani (magnetic nanomaterials; spintronics)
V. N. Kulkarni (ion beams; fabrication)
Department of Chemical Engineering
Animangsu Ghatak (microfluidics; soft fabrication)Yogesh Joshi (polymer-clay nanocomposites)
Nishith Verma (carbon nanocomposites)Jayant K. Singh (simulations of soft materials)
Department of ChemistrySandeep Verma (self-assembly; nano-bio)
Department of Materials and Metallurgical EngineeringAshish Garg (thin films; nano-structures)
Department of Mechanical EngineeringShantanu Bhatacharya (nano-fabrication; MEMS)
Department of PhysicsRajiv Gupta (SPM; Raman)
(Additional members may be co-opted depending on the focus of research---soft materials based patterning and their
expertise in the Unit resources)
Major Facilities at Nanosciences Center
About 2500 sq. ft. of class 1000-100 clean rooms
Fabrication resources
Characterization resources
Collaborations: Northwestern; UIUC; UCI; Cambridge; NIST; JNCASR; IISc…….
Fall 2007
Fabrication
Focused Ion Beam (Dual Beam FIB)E-Beam LithographyBroad Beam Ion MillMaskless PhotolithographyPulse laserCoatingLangmuir-Blodgett DepositionNSOM UV LithographyNanoimprint LithographyPolymer Ink-jet Printing
High temperature furnaces…..
Characterization
Confocal MicroscopyMicro-RamanScanning Probe MicroscopiesNear-field Scanning Optical Microscopy (NSOM)Imaging and Spectroscopic EllipsometryProfilometers (Mechanical and Optical)SEMWAXRD; SAXSQUIDOptical MicroscopesContact Angle Goniometer……..
Specific Scientific Objectives:
Development of novel and facile techniques for patterning, structuring and fabrication using soft materials like polymers, gels, biological materials
Development of functional interfaces such as super-hydrophobic surfaces and super adhesives based on meso patterning of surfaces
Attachment –detachment energetics of sub-micron particles to surface and modulation by surfactants
Synthesis of ordered arrays of quantum dots and nanowires including doped oxide and metal alloys and magnetic materials
Exploration of interfacial instabilities and failure mechanism in soft nano-structures
Development of soft composites including polymer-nanoclay composites, thin film of meso-porous silica and its nano composites
Magnetic nano particles and assembliesDevelopment of computational nanomechanicsMicro-SQUIDS and nanoscale magnetics including
magnetic relaxation and supermagnetismFabrication of carbon meso-structures based on soft
fabrication techniquesMicrofluidic based devices and sensors
Current Areas of Nanosciences at IITK
Fabrication using FIB, E-beam (masters; devices…)
Novel soft-lithographies for large area, meso-patterning: “top-down” meets self-organization
Nano- mechanics of soft confined materials
Fabrication of novel MEMS: C-MEMS for micro-battery and cell-arrays
Nanocomposites: polymer, carbon, clays, silica...
Meso-textured Smart functional surfaces: superwetting; smart adhesives; optical and printing surfaces……
Interfacial/Colloidal interactions in aqueous media with polymer/surfactant adsorption
Stability of soft nanostructures including structures produced by nanoimprint lithography
Nanobiology: Scaffolds
Nanoparticles, nanofibres and nanofilms: semiconductors, metals, polymers, carbon, ceramics, organics…..
Nanostructured Magnetic Materials; spintronics
Nano-Patterning of Soft Materials
In devices; MEMS/NEMS; Sensors; Smart Surfaces; Micro-fluidics; Super-capacitors and Batteries; Smart Adhesives; Functional Interfaces………..
1.Facilities for large area, rapid patterning: Inkjet Printing, Gravure Printing, NanoimprintLithography, Laser Writing, FIB, E-beam……
2. Technology development for new patterning methods based on self-assembly, including e-field assisted patterning, phase change, dewetting,phase separation and stress-engineering, Nanocoatings; Fast micro/nano Texturing…….
3. Products:
Smart and Functional Surfaces by Patterning:
Adhesives,
Anti-reflective Coatings,
Structured Colors,
Anti-fouling,
Super-wetting
Carbon patterning: MEMS, High Area Batteries
Bio- and Chemical Sensors
Fluidic Devices
Opto-electronic Devices
Difficult to fabricate
Functional patterns
Additional Recent Nano-Grants:Self organized patterning of polymers, British Council (UKIERI), Rs. 2.4 millions (co-PI from UK: Prof. UllrichSteiner, Cambridge University).Carbon MEMS, part of Indo-US Center for Advanced and Futuristic Manufacturing, Indo-US Science and Technology Forum, 2006-2008. Rs. 6.4 million (Coordinator: Prof. Amitabha Ghosh; US collaborator: Prof. Marc Madou, UCI).Manufacturing Robust Nanostructures: Materials, Methods and Metrology, Indo-US Science and Technology Forum, Frontiers of Engineering (FOE) Award for collaboration with NIST Rs. 2.5 million. (US co-PI: Christopher Soles). Mesostructured Functional Thin Films and Interfaces of Soft Materials, Department of Science and Technology, 2007--2010. Rs. 49 million.Understanding adhesion of soft particles, Proctor & Gamble, 2008-2009. Rs.3 million
Some InnovationsA novel micro/nano fluidic adhesive has been prepared
and shown to be vastly more effectiveA novel nano fabrication method based on gel
miniaturization has been proposedThree novel methods for self-organized sub-micron
patterning of polymers on large areas have been developed and currently being further fine-tuned for applications.
A novel highly asymmetric nano-porous silica surface has been synthesized. One face of this surface is super-hydrophobic and the other is hydrophilic. Potential applications are in textile and barrier coatings.
Application of electric fields to pattern the surfaces of soft visco-ealstic materails on sub-micron lengthscalesby spatio-temporal variation of the e-field.
A novel technique for synthesis of colloidal solution of nanoparticles has been developed. This pulsed laser based method allows synthesis of multicomponent oxide and metal alloy nanoparticles, which is rather difficult to achieve with the know methods.
Stress tuning has been used to create novel 2-dimensional fractal networks of iron.
2006-07Over 70 publications in International Journals
3 patents filed and 1 disclosure
14 PhD students and several project staff trained
In addition to the Unit funding ~ 15 Carores, 6 additional nano related projects ~ 7 caroresgenerated; two industry supported
Collaborations with Cambridge, NIST, Lehigh, UIC, JNCASR, Saha Institute, TRDDC, NUS………..
Exciting new discoveries!!!!
Grand Challenges of Soft Patterning“Top-down” Meets Self-Organization!!
Sub-micron Features on Large areas (> cm; beyond!)
Rapid (m per second !! ); (roll-to-roll?; parallel)Integration across Different Materials (hydrogels,
ceramics, carbon……)Process Complexity; Resources, Cost….Patterning beyond Master: One Master, Many
SlavesIn-situ Tuning of PatternsProgrammable Patterning
Functional Nano-structured Interfaces: Smart-adhesives
Producing High Strength Re-usable Soft Adhesives: Bio-inspired Adhesion
Examples of Bioadhesives
Adhesive pads of insects
Setae of Gecko
Elastic Film
td h
F G,
J/m2
7 83 54 6210.0
0.3
0.6
0.9
1.2
1.5
1.8
9 10Microfluidic adhesive
(Majumder, Ghatak & Sharma; Science,2007)
Fabricating in ‘Exotic’ Functional Materials:Carbon: Micro/nano Webs and C-MEMS
Energy: micro battery, micro-fuel cell, super capacitor…. Electronics: molecular switches, memory……Biomaterials: C-MEMS…….Environment: Adsorption & catalytic media…
With Marc Madou, UCI
Difficult to Fabricate Functional Materials: Carbon Energy: micro-fuel cell, micro battery, super capacitor….; Biomaterials…….
Pyrolyzed Polymer structures !!
Stability: Stick
Functionalization:Carbon fibresCollaborator: Marc Madou, UCI
Nano-Imprinting Challenges:
Uniform high pressure/temperatureConformal contact/Curved surfacesStamp Removal
Meeting the ChallengesFlexible thin foil stampsSolvent vapor assisted softening of polymer filmsSpontaneous conformal contact by adhesive
forcesSoluble moulds/masters/stamps
Structural Colors by Micro-patterning: Adhesive Force Lithography with Flexible Foils: Variety of Surfaces and Materials
PS polymer;6 cm2
Hydrogel
Sharma et al., Macromolecules 2006Almost any polymer on any surface!!
Curved
Patterning Beyond Master : Pattern Miniaturization
400 nm structures starting from 800 nm masterSharma et al.
Patterning by Elastic Contact Instability: A New Micro/Nano Fabrication Toolpattern length scale ~ 3 H
A. Positive Replica
B. 2-D Bifurcation
C. Compress: Negative replica
D. Pull
E. Feature size reduction: Thin film
W ~ 2L Sharma et al. Langmuir 2006
Patterning by Electric Fields: A New Fabrication Tool
Sharma, Shenoy, Narayan et al., Adv Mat 2006
Controlled Self-organized Dewetting: A New Fabrication Tool
Sharma et al.
Robust Nanoimprint LithographySharma & Soles (NIST)
1. Imprinting of soft elastic films
2. Imprinting of viscous polymeric liquid films
ISSUES:A.Stress, strain, flow and structure relationshipsB.B. Stability and fidelity of imprinted structuresStability and fidelity of imprinted structuresC.C. MetrologyMetrology
m o ld ( S i , Q u a r tz )
im p r in t m a t e r i a ls u b s t r a te
r e l e a s e
R IE e t c h
im p r in t( f o r c e ,U V , h e a t )
m o ld ( S i , Q u a r tz )
im p r in t m a t e r i a ls u b s t r a te
r e l e a s e
R IE e t c h
im p r in t( f o r c e ,U V , h e a t )
Nano-Patterning of Surfaces by Self-assembly: Sandeep Vermaa
b
Adenine-Silver
Metallaquartet
HOPG
J. Am. Chem. Soc. 2006, 128, 400-401
Adenine-Silver
Duplex
HOPG
a b
J. Am. Chem. Soc. 2007, 129, 3488-3489
J. Am. Chem. Soc. 2006, 128, 400-401
ab
a b
J. Am. Chem. Soc. 2007, 129, 3488-3489
Sandeep Verma, Chemistry
Peptide morphologies
FFPP PPFF PFFPJ. Pep. Sci. 2007, 14, 118-126
Chem. Eur. J. 2008,14, 1415-1419
Angew. Chem. 2008,47, 2217-2221
Angew. Chem. 2008,47, 2860-2863
Laser Ablation Assisted Growth of Quantum Dots & Quantum Wires and Their Magnetic Properties
Ag colloid in aqueous SDS (R. Budhani et al.)
10 20 30 40
10
20
30
Cou
nts
D iam eter (nm )
(b)
50 nm50 nm (a)
(b)
-60 -30 0 30 60-600
0
600
Applied field (kOe)
Perpendicular In-plane
(f)
M (e
mu/
cc)
-600
0
600
TG = 750 0C
M (e
mu/
cc)
(e)
-600
0
600
-60 -30 0 30 60
TG = 700 0C
M (e
mu/
cc)
(d)TG = 700 0C
TG = 750 0C
TG = 800 0C
(a)
(b)
(c)2.0 μm
2.0 μm
2.0 μmSEM images and Perpendicular magnetization loops of 50 nm CoPt thin films deposited at various substrate temperatures at a growth rate of 0.4 Å/sec on single crystal STO (001). All the samples were post annealed for 25 minutes. Magnetization panel for the sample grown 800 0C also shows data for in-plane configuration.
CoPt Fractals and Nano dotsBudhani, Rakshit et al. Appl. Phys. Lett. 02511 (2006)
Fabrication using FIB
1. 2-D Patterning (masks, molds, stamps)
2. 3-D Structures (AFM tips, cantilevers, devices)
Focused Ion Beam: Nanomachining and Beyond
Sample(mounted on a precision
Ion Beam(Ga+ 3-30 KeV)Spot size 7 nm
ScanGeneratorfor SEM
ScanGenerator forFIB
Monitor
SED/SID
NN NO
VA
OVA
O
VA NN N
AN
OA
NO
AN
OLL L A
BA
BA
B
Nova NanoLabNova NanoLab Nano- Milling
Deposition
Micro Squid with NbFilms; Anjan Gupta et al.
EXAMPLES
Holes (100 nm dia.) drilled in NbSe2 for patterning the magnetic vortex states; Satyajit Banerjee et al.
Platinum electrodes separation 50 nm; I-V characteristics; Child Langmuir law at nanometer scales; S. Bhattacharjee
Superconducting Nano-Devices
-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3
-4
-2
0
2
4
-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3-20
0
20
40
60
80
100
120
140
160
dV/d
I in
ohm
Current in mA
PLOT of dV/dI vs I
volta
ge in
mV
Current in mA
V-I CHARACTERISTIC of Nb JJ
IC ~ 80 µA
(180(L) x 170(w) x 80(t) nm3)
-0.4 -0.2 0.0 0.2 0.4
-4
-2
0
2
4
Vol
tage
in m
V
Current in mA
V-I Characteristic of Nb SQUID (H=0)
-0.4 -0.2 0.0 0.2 0.4
0
10
20
30
40
dV/d
I in
ohm
Current in mA
SQUID Loop Area: (3.3 x 3.3) μm2
JJs:: 200(L) x 180(w) nm2
Maskless optical lithography + FIB milling; A. Gupta et al.
Carbon Cantilevers and Particles on AFM Tip
Kulkarni et al. Sharma et al.
AFM measurements of force-distance require dense spherical carbon particles 2-5 micronattached to the AFM tip
AFM Tips for Nanoindentation
AFM tip of well defined shapes are required; grown Tungsten tips of hemispherical shape with the required end radius of 50 nm
Sharma, Kar, Deva et al.
50 100 150 200 250 300 350 400 450 500-20
0
20
40
60
80
100
120
140
160
(z1,s1)
s [p
iezo
dis
plac
emen
t, nm
]
z [diflection, nm]
z =(z1-z2)
s = (s2-s1)
h = (z-s)(z2,s2)
tip movement
range of analysis
Fig 2. Vertical displacement
0.2 0.4 0.6 0.8 1.00
50
100
150
200
250
300
350
400
Ela
stic
mod
ulus
[MP
a]
h [indentation depth, nm]
Fig. 3 Modulus vs indentation depth
Meso-patterning of thin polymer films by atomic force microscope assisted electrohydrodynamic
nanolithography
Xie, Chung, Bandyopadhyay, Sharma, et al, J. Applied Phys. 103, 024307 (2008). selected paper in Virtual Journal of Nanoscale Science & Technology, 17 (5), 2008.
0th1st2nd
Fabrication of Small Things:
Top-Down
Bottom-up
Self-organization
Miniaturization
Ghatak, Sharma et al. Adv Mat (2007)
2006-07Over 70 publications in International Journals
3 patents filed and 1 disclosure
14 PhD students and several project staff trained
In addition to the Unit funding ~ 15 Carores, 6 additional nano related projects ~ 7 caroresgenerated
Collaborations with Cambridge, NIST, Lehigh, UIC, JNCASR, Saha Institute, TRDDC, NUS………..
Exciting new discoveries!!!!
Best way to predict the future is to invent it….