Theme 1.1: Electro-Mechanical Coupling in Soft Materials: Energy Scavenging and Storage

IIMECInternational Institute for

Multifunctional Materials for Energy Conversion

Theme 1.1: Electro-Mechanical Coupling in Soft Materials: Energy Scavenging and

Storage

Zoubeida OunaiesPenn State University

Iimec2012-TAMUCollege Station, TX

1/18/02-1/19/02

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Overview

Focus•Research agenda•Target applications•Scope of activities

Highlighted Projects

•Development of natural fiber composites•Electric field-manipulation of nanoreinforcements •Nanodielectrics for energy storage•Structural health monitoring of polymer matrix composites

Break-out Session

•Schedule/Participants•Goals•Some highlights

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Overview

Focus •Research agenda•Target applications•Scope of activities



Break-out Session


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Research Agenda

Materials exhibiting electro-mechanical coupling,such as piezoelectric and ferroelectric ceramics, electro-active polymers, and nano-composites for sensing, actuation, electrical energy harvesting, conversion and storage

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Multifunctional Materials for Energy Conversion 6

Energy Harvester

Diode Rectifier Circuit

Capacitor /Battery

Bottom Electrode

Top Electrode

Piezoelectric Material

1

32

1

32

1

32

Unimorph HomogeneousBimorph

One Approach…

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Challenges

Shortfalls of current electromechanical materials include:– small electromechanical coupling

coefficients– high actuation voltage – Trade off between blocked stress, free

strain and applied electric field– low mechanical to electrical energy

conversion, resulting from dissipative dielectric losses

– Low energy and work densities– Restricted operational temperatures and

frequencies– Limited development of additional

‘functionality’

EAP Achieved strains

(%)Electric field

(MV/m)

Polyurethane (Deerfield)

Silicone(Dow Corning)

PVDF-based electrostrictors

PVDF and copolymers

11

32

4

0.7

150

144

>10

>10

Barium Titanate (BaTiO3)

~0.83 1

Lead Manganese Niobate (PMN)

~0.1 1

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Can Nano Help Smart?

Introduce small amounts of Nanoparticles to achieve dramatic changes in Mechanical, Thermal, Physical,

Electrical and / or Chemical Properties

Introduce Multifunctionality (Structural + Electric; Structural + ElectroMechanical; Structural + Permeability; Structural + Biocompatibility)

Minimal change in density of the polymer

At the same volume fraction (10 vol%).

Microcomposite Nanohybrid

Effect of particle shrinking from micrometric to nanometric size: interface increasingly dominates!

particle

interface

Particle diameter 10 nm 1 mm

# particles/ cc 1.9 x 1017 1.9 x 1011

Surface area / cc 60 m2 0.6 m2

Average Interparticledistance

8.5 nm 850 nm

Understand opportunities afforded by polymer nanocomposites to address current State-of-the-Art challenges in smart materials.

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Nanostructured/Nanoreinforced Polymers

Nanofilled polymers Nanostructured hybrids-Capitalize on inherent filler properties to enhance performance of composites

-Introduce dramatic enhancement, new physical properties and novel behavior that are absent in unfilled matrices and particles

nanoscale effect!

Toughness Increase using Nanoclay (Shah et. al. 2004)

1.0E+06

1.0E+07

1.0E+08

1.0E+09

1.0E+10

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012 0.0014

SWNT concentration

Stor

age

mod

ulus

Ec

(Pa)

Halpin Tsai theory below TgExperimental below TgHalpin Tsai theory above TgExperimental above Tg

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Overview




Break-out Session


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Target Applications

Light Flexible Piezoelectrics Piezoelectric Ceramics and Ceramic-based Composites

Wind Turbines

Smart Textiles

Power harnessing in ocean surges/waves along coastal regions

Active fiber composites

d

Autonomous, unmanned, self-powered, and adaptive

Nanocomposites

P+

n

P+- - - - -

Startup and reference

circuitsPiezoelectric transducer

> 4V

----

- -

- -- -Silicon Oxide Polysilicon

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Overview




Break-out Session


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• Exchange of students for periods of 4-6 months– EPT to TAMU– EPT to PSU– PSU to Morocco– Morocco to PSU

• Faculty visits– EPT faculty to PSU

• Competing for additional funding– Tunisia-Morocco cooperation for scientific research and

technology– USA-Tunisia-Morocco State Department Grant– Fullbright– Tunisian ministry of higher education

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• Co-advising of PFE, MS and Ph.D. theses

• Journal publications and conference proceedings

• International conference organization

• Non-profit professional society: NATEG

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Overview




Break-out Session


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SWNT (vol%)

0.0 0.5 1.0 1.5 2.0 2.5

M (m

2 /MV

2 )

10-910-810-710-610-5

10-2

10-1

100

M3333 SWNT +PI (1Hz)M1133 SWNT +PI (DC)M1133 SWNT +PI (0.5Hz)M1133 Polyurethane [18] P(VDF-TrFE) [19](calculated using Q and dielectric constant)

M3333

Trend to ease reading of M3333 data (1Hz)Trend to ease reading of M1133 data (DC)Trend to ease reading of M1133 data (0.5Hz)

SWNT (vol%)

0.0 0.5 1.0 1.5 2.0 2.5

M (m

2 /MV

2 )

10-910-810-710-610-5

10-2

10-1

100

M3333 SWNT +PI (1Hz)M1133 SWNT +PI (DC)M1133 SWNT +PI (0.5Hz)M1133 Polyurethane [18] P(VDF-TrFE) [19](calculated using Q and dielectric constant)

M3333

Trend to ease reading of M3333 data (1Hz)Trend to ease reading of M1133 data (DC)Trend to ease reading of M1133 data (0.5Hz)

Palm tree, Alfalfa and Agave Plant.

Development of Natural Fiber Composites

Natural fiber extraction and characterization

Composite elaboration, synthesis and processing

Multifunctional property measurement

Model development

Target application

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Palm tree, Alfalfa and Agave Plant.

Development of natural fiber composites

Natural fiber extraction and characterization

Composite elaboration, synthesis and processing

Property measurement

Model development

Target application

Tunisia

U.S.A.Morocco

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New Composite Materials with Natural Reinforcement

Applied Mechanics and Systems Research Laboratory TUNISIA POLYTECHNIC SCHOOL

Preparing Alfalfa short fibers specimens at PSU (varied lengths, random reinforcement)

.

.Elaboration of a new composite material where the reinforcement consists of natural fibers extracted from Alfalfa plants:

identify the thermo-mechanical properties of natural fiber separately and in the composite material

conduct both numerical and experimental measurements

investigate different arrangement of fibers (unidirectional, woven and random with varied lengths

Interest in integrating natural occuring fiber materials into composites

because of their functional and ecological qualities.

Tunisia possesses abundant sources of Alfalfa plants with promising physical and mechanical characteristics.

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Collaborative Process…

Development of natural

fiber composites

Faculty visit

through the

Fullbright program

PSU student at

PSU, recruited from EPT

Funds from the Tunisia-

Morocco Cooperation for Scientific

Research program

Short term student

exchange through IIMEC

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Overview



•Development of natural fiber composites•Electric field-manipulation of

nanoreinforcements •Nanodielectrics for energy storage•Structural health monitoring of polymer matrix composites

Break-out Session


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0.1wt%

Electric Field-Manipulation of Nanoreinforcements Flexibility and TransparencyCellulose

Abundantly available Bio- compatible Low cost Bio-degradable Easy to process

V. Favier et al 1995 Macromolecules

Plants, Sea tunicates, Wood

Mechanical reinforcementActuation

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Acid Hydrolysis

Multi-scale Processing and Characterization

Synthesis and Extraction

300 V/mm, 30 min

10 Hz 25 kHz

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Frequency (Hz)

101 102 103 104 105 106 107

Die

lect

ric C

onst

ant

6

7

8

9

10

11

Random 1Hz10Hz100Hz1KHz10KHz

Frequency (Hz)

101 102 103 104 105 106 107

Die

lect

ric c

onst

ant

7

8

9

10

11

12

Random 1Hz10Hz100Hz1KHz10KHz

Sample

Pure PVAc Random 1Hz 10Hz 100Hz 1KHz 10 KHz 0.0

0.5

1.0

1.5

2.0

2.5

Elastic Modulus (MPa)Tensile Strenght (MPa)Percentage Elongation (X10-3)

Multifunctional Property Measurement and Analysis

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Collaborative Process…

Cellulose-based nancomposites

Conference and workshop co-organization

Co-advising PhD student from Caddi

Ayad

Hosting TAMU student in lab in

Morocco

Hosting Caddi Ayd student at

PSU

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Overview

Focus• Research agenda• Target applications• Scope of activities


• Development of natural fiber composites

• Electric field-manipulation of nanoreinforcements

• Nanodielectrics for energy storage

• Structural health monitoring of polymer matrix composites

Break-out Session• Schedule/Participants• Goals• Some highlights

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Material Y(GPa)

Max. Strain (%)

CP2+0.1wt%NT

1.6013.0

3.00

3.500.4

1.2%

0.5%

2.2%2.0%

1.01

1.243.43

56.0

28.8

80.0200.0

PPI+1.0wt%NT

PVDF+0.2wt%NTPVDF-TrFE-

CupC

0.37

E(MV/m)

1.00.2

1.40Irradiated PVDF

Polyurethane0.40 150.0 5.0% 0.50 ____0.02 100.0 10.0% 0.1 10.0

26

EPT-PSU Collaboration through Student and Faculty Exchange

-Student completed MS thesis, co-advised by Chafra,Najar, Ounaies

-Student conducting PhD research, co-advised by Chafra and Ounaies

-Faculty exchange leveraging the Fullbright program: Dr. Moez Chafra from EPT to PSU. EPT students, Emna Helal ,

conducting research at TAMU.

TiORRO

ORRO Hydrolysis

TiOH HO

OH HO

PolycondensationTi

OO

OO TiO

O

TiO2

-NH2

Amine group is electron donating

C-F is electron

withdrawing

Dipole-Dipole Interaction

FFTiO2

Ways Toward Better Dispersion:

Particle Surface Functionalization

In-situ Sol-Gel Process inside Polymer Solution

experimental evidence of electrostriction by addition of small quantities of NPs.

1

2

3

tVΔt

Sensor

1

2

3

1

2

3

tVΔt

Sensor1

23

L

tw

V

1

23

1

23

L

tw

V

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Commercially available polymers for capacitors:Polypropylene: Energy density 1-1.2J/cc

Inexpensive

Easy to process

Current requirements

Energy density (> 4 J/cc)

Low loss (<0.005)

20 '21

bVt

AU

Monolithic materials: trade-off between ’ and Vb!

Breakdown versus dielectric constant“Proposed universal relationship between dielectric breakdown and dielectric constant” J. McPherson et al. 2002. Texas Instruments, Silicon Technology Development.

Motivation: Nanocomposite Dielectrics.

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Motivation: Nanocomposite Dielectrics.

To Store Large Amount of Electrical Energy at High Voltages for Long Periods of Time Without Significant Current Leakage.

• Enable Lightweight, Compact, High-energy-density Capacitors • Optimize The Dielectric Permittivity And The Dielectric Breakdown Strength

2.3vol% NWTiO2@APS-PVDFWith functionalization

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Sample ε' @1kHz Tan(δ)@1kHz Eb (MV/m) U (J/cc)

Pure PVDF 7.2 0.014 179 1.01

2.3vol% F(NW) 8.7 0.016 184 1.30

4.6vol% F(NW) 10.5 0.023 339 5.34

9.2vol% F(NW) 12.8 0.069 147 1.22

Enhancement > 500% with 4.6vol% F(NW)-PVDF

Some Recent Results…

Samples thickness ranging from 17mm to 24mm

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Breakdown Mechanisms

Possible mechanisms: Intrinsic breakdown

Electronic breakdown

Thermal breakdown

Electromechanical breakdown

Schematic representation of the relationship between the breakdown

field Eb, the time to breakdown t, and the sample thickness d, Bluhm, 2006 [5]

Sample

Electrodes

Coulombic attractive forces

FSpacer

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Dielectric breakdown thickness dependence

Sample thickness (mm)

10 20 30 40 50 60 70

Die

lect

ric b

reak

dow

n (M

V/m

)

50

100

150

200

250

300

350

400

Pure PVDF2.3vol% F(NW) 4.6vol% F(NW)

Possible mechanisms:

Intrinsic breakdown

Electronic breakdown

Thermal breakdown

Electromechanical breakdown

31

The strongest dependence on

thickness is for the composite with

the highest particles content

Ramp = 500V/s

When the thickness increase, more

defects are present in the sample

decrease in the dielectric

breakdown

Breakdown mechanisms: Intrinsic?

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Overview

Focus• Research agenda• Target applications• Scope of activities


• Development of natural fiber composites

• Electric field-manipulation of nanoreinforcements

• Nanodielectrics for energy storage• Structural health monitoring of

polymer matrix composites

Break-out Session• Schedule/Participants• Goals• Some highlights

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Structural Health Monitoring of Polymer Matrix CompositesNon linear Ultrasonics Technique

Novel SHM System

Results: Detection of Impact Damage

Experimental Setup for Impact Damage Detection in Composite Plates

Objective: Development of a new Structural Health Monitoring methodology based on damage detection via non –linear wave modulation characteristics.

Conclusions: Ability to reveal even small

damage sizes Efficient for all common damage

types of composites: Delamination Debondings Matrix cracks Single lap adhesive joints

Healthy 4J Impact load

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Modeling of Delaminated Composite Beams with Active Piezoelectric Sensors

Objectives: Development of new FE models with1) Layerwise mechanics2) Additional DOFs to simulate delamination3) Coupled electromechanical system

Conclusions: • Feasibility to reveal damage signatures • Ability to simulate delaminated system response• Agreement with experimental measurements

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BREAK-OUT SESSION 1

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Afternoon break-out session:

3:15-5:00pm Room 1011B

Moderated by P.Sharma and Z. Ounaies

-Focus on electro-mechanical, mechanical reinforcement, opto-electric coupling, thermal management

-Planning next year’s collaborations and activities

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Technical Outcome Following Kick-off Meeting

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Documents

Theme 1.1: Electro-Mechanical Coupling in Soft Materials: Energy Scavenging and Storage