w.wang 198

Three main kinds of materials

metals, plastics and ceramics.

Electroactive polymers

w.wang 199

Preface

I am inclined to think that the development of polymerization is, perhaps, the biggest thing chemistry has done, where it has had the biggest effect on everyday life. The world would be a totally different place without artificial fibers, plastics, elastomers etc. Even in the field of electronics, what would you do without insulation? And there you come back to polymers again.--- Lord Todd, president of the Royal Society of London, quoted in Chem. Eng. News 58 (40), 29 (1980), in answer to the question, What do you think has being chemistry’s biggest contribution to science, to society?

From clothing to the artificial heart, polymers touch our lives as do no other class of materials, with no end in sight for new uses and improved products.

w.wang 200

PolymerMacromolecule

Out line of the science of large molecules

Polymers

Biological materials

Nonbiological materials

Plant fiber, starch saccharin etc.

Plastics fibers, elastomers

Rubber, wool, cellulose, silk and leather etc.

w.wang 201

• Polyethylene• Poly(vinyl chloride)

• Polyisobutylene

• Polystyrene

• Polycaprolactam (6-nylon)

• Polyisoprene (natural rubber)

CH2 CH2 CH2CH2

CH2 CHCl CH2CHCl

CH2 C

CH3

CH3

CH2 C

CH3

CH3

CH2 CH CH2 CH

N(CH2)5C OHH

H O

N(CH2)5C

H O

CH2 CH CH2 CH2

CH3

CH2CH CH2 CH2

CH3

Some linear high polymer, their monomers, and their repeat units

Polymer Monomer Repeat Unit

w.wang 202

Polymerization

• Step-reaction (Condensation) polymerization

• Radical chain (addition) polymerization

• Ionic and coordination chain (addition) polymerization

• Copolymerization

w.wang 203

Characterization for Analysis and Testing of Polymers-----Common Methods and Equipments

• Dynamic light scattering spectrometer- thermodynamics properties

• Mass spectrometry- structure of low-molecular- weight species

• Infrared Spectroscopy (IR) - structure

• Nuclear Magnetic Resonance Spectroscopy 1HNMR and 13CNMR -chain configuration,sequence distribution, and microstructure

• X-ray diffraction analysis WAXD- the spatial arrangements of the atomsSAXS: larger periodicities

• Light Microscopy (SALS)- spherulites or rod and phase-contrast

• Electron Microscopy and Electron Diffraction

• Scanning Electron Microscopy (SEM) and Transmission Electron Micrograph (TEM)

• Deferential Scanning Calorimetry (DSC)- thermal analysis

• Stress-strain properties in Tension

w.wang 204

States of Polymer

Polymers

liquid states

sol- gel states

solid states

Biological field

how to make gel, film, fiber and composite etc.

artificial muscle, switch and smart window etc.

film, fiber and container etc.

artificial muscle, switch and smart window etc.

w.wang 205

w.wang 206

(a) (b)X-ray diffraction patterns for unoriented (a) and oriented (b) polyoxymethylene (courtesy of E.S. Clark)

Ringed spherulites of poly(trimethyleneglutarate) observed in the optical microscope between crossed polarizers (Keller 1959)

Electro micrograph of a portion of a ringed spherulite in linear polyethylene (photograph by E.W. Fischer, from Geil 1963)

w.wang 207

SAXS and WAXD patterns (end view) from polyethylene/carbon blend materials with the indicated compositions

w.wang 208

(a) Hv SALS photos of low andmedium density polyethylene

(b) Hv SALS photos with indicated draw ratios (stretching direction is vertical)

(c) Surface replica electron microscopy of Polytetrafluoroethylene (Teflon) with different heat treatments (b) and (d) and corresponding with Hv SALS (a), (c)

w.wang 209

Utilizing plastics for car components

Proof , Seat Poly(vinyl chloride)

HandlePoly(vinyl chloride)polypropylene

Air filterPhenol resinPolyamide

BumperPolypropylenePolycarbonate

TireSynthetic resin(styrene)

Door handlePolycarbonatePolyacetal

CarpetNylon

BumperPoly(vinyl chloride)

w.wang 210

Environmental stimuli

♦ Temperature♦ Solvent, pH ♦ Electric field♦ Magnetic field♦ Light or UV

Response

♦ Phase♦ Shape♦ Optics♦ Mechanics♦ Permeation rates♦ Recognition

Active materialssensing and responding to change of environment

This fish changes coloraccording to the surroundings

Flowers are sensitive to light

w.wang 211

Polymers with electrical and electronic properties

Electrical

Electronic

Optical

Thermal

Chemical

Physical

Polymers

Conventional polymers (using their strength, flexibility, elasticity, stability, mould

ability, dielectric properties, etc.)

Specialty polymers(using their electrical

conductivity, photoconductivity, nonlinear optical effects, dielectric properties, etc.)

w.wang 212

Electroactive Polymer (EAP) Materials • Electric EAP--- PVDF-based Ferroelectric polymers

• Ionic EAP---Electroactive polymer gels---Ionomeric Polymer-Metal Composites

• Non-ionic EAP--- PVA-based

• Carbon nanotube Actuator

• Conductive Polymer---PPy and PANI--- PEDOT and PEDOP based

w.wang 213

Applications and application potentials

• Antenna and mirror

• Biomimetics and switching technologies---Nafion, Flemion, poly(vinyl alcohol) (PVA) gel,

conducting polymer and carbon nanotubeactuator

• Switching window, electromagnetic shutter and display technologies

--Acrylamide and vinyl derivative copolymer, copoly(Aam/vdMG) gel and electrochromicpolymer, ProDOT-(CH3)

• Drug delivery system--- Polymer gel and Conducting polymer:

e.g. polyacrylamide gel polypyrrole(PPy)• Sensor

Nafion and polyaniline (PANI)

w.wang 214

Comparison of energy storage capabilities of several dielectric materials and capacitors technologies

Applications

w.wang 215

Space mirror…

(a) Echo 1 passive satellite (courtesy NASA).

(b) Inflatable antenna experiment on orbit. The inflatable antenna was packaged into the reusable Spartan satellite seen on the right (courtesy NASA).

(c) A space shuttle view of the L’Garde’sinflatable antenna experiment (IAE).

(d) Dielectric actuator demonstrated to expand and relax (courtesy of R.Kornbluhand R.Pelrine, SRI International).

w.wang 216

How they work?• Antenna

EAP

w.wang 217

(a) Principle of operation of dielectric elastomer actuators.

voltage off voltage on

(b) Biaxially uniform prestrainand circular electrodes.

voltage off voltage on(c) Anisotropic prestrain with

linear electrodes.

How they work?

w.wang 218

Dielectric actuator

W.-C. WangDielectric Actuator

w.wang 219

Dielectric actuator

W.-C. WangDielectric Actuator

w.wang 220

Snake-like actuator

w.wang 221

w.wang 222

Linear actuator

w.wang 223

Fish actuator

SRI

w.wang 224

Walking robot

SRI

w.wang 225

Animation

UCSD

w.wang 226

Without E-field With E-filed(b) Particle suspension forms chains when

electric field is applied

(c) Electrorheological fluid at reference (left) and activated state (right) [courtesy of ER Fluid Developments Ltd, UK]

(a) Bending of a polyacrylic acid gel rod sodium hydroxide. DC applied field, cathode (negative) at a bottom. Gel swells on the anode side and bends toward the cathode [Shiga, 1997]

How they work?

w.wang 227(b) Smiling robot of Hidetoshi Akasaw

(d) Dynamic gestural figure with muscles exposed.

(a) Facial muscle that produced expression [Netter, 1995]

(c) A photographic view of a human hand and skeleton as well as an emulated structure for which EAP actuators are being sought [Courtesy of Garham Whiteley, Sheffield Hallam University, UK]

Applications

w.wang 228

How they work?

Gel structure:• Solid phase - crosslinked polymer matrix• Liquid phase - solvent

Phase transition - discontinuous change of properties, size, shape, etc.under discrete change of environment

Molecular interactions - ionic, hydrophobic, hydrogen bonding,van der Waals

Polymer Gels

w.wang 229

How they work?Current applications: Medicine and Biotechnology

2) Molecular separations

BB

B

B

B

B

B

BC

C

C

C

C

CC

CCB

B B

B

+ stimulus - stimulus

filter Cfilter B

recycle gel

1) Drug delivery devices

BB

B

B

stimulus+

-

B

B

B

B

w.wang 230

Study on several EAPs

(1) Poly(vinyl alcohol) (PVA) gel

(2) Nafion and Flemion

(3) Copoly(Aam/vdMG) gel

(4) Electrochromic polymer, ProDOT-(CH3)

w.wang 231

• Polyvinyl alcohol (PVA) gel:

Material development

- actuation in electric field by contraction and bending

- influence of structure to deformation:• molecular level• macroscopic level

- fastest response (<1s)

- low strength material

- high applicable voltage

Holder Gold film

s

w.wang 232

at-PVA (DP2100, 80min) E = 290 V/mm

2

2.1

2.2

2.3

2.4

2.5

0 100 200 300 400

Time (s)

Thi

ckne

ss (m

m)

• Degree of polymerization (DP) - 1400, 2100, 17900

• Tacticity - atactic, syndiotactic

st-PVA (DP2000, 80min, heated) E = 310 V/mm

22.22.42.62.8

33.23.4

0 100 200 300 400 500

Time (s)

Thi

ckne

ss (m

m)

Influence of structure - molecular level

0

5

10

15

20

25

0 200 400 600 800

E-field (V/mm)

Stra

in (%

)DP1400DP2100DP17900

d ∆x

x

E

w.wang 233

Cathode

Anode

Stress Generation

w.wang 234

AIEbj =⋅⋅ρ=

φ−= gradE

ρ=∇D

j - current densityρ - charge densityb - charge mobilityE - electric field strengthI - electric currentA - surface of condenser platesφ - electric potentialD - electric displacement

−

+

εε

−φ=φ )()()()(/

0E0ExbA

I2I3

bA0x 323

2

212 x

bAI20ExE

/

)()(

ε+=

• Potential and electric field in dielectric material

• Dielectric liquid can be ionized upon high E-field

Mechanism of Electric Actuation

w.wang 235

• For the PVA gel having 96-98% liquid phase, solvent pressure isconverted to gel stress, with the efficiency η

)()( xpx ⋅η=σ

• Charge injection to the solvent (DMSO) in PVA gel, upon appliedE-field

DM

SO

DMSO

DMSO

DM

SO

DMSO

DMSO

DMSO

OFF

PVA network

d

+

+

-

+++ DMSO

DMSO

DMSO

DMSO

DMSO DMSODMSO

DM

SO

DMSO

+∆d

ON

• If the dielectric is liquid, Maxwell stress converts to fluid pressure

dx

dVV

89xp

2

−ε

≈')(

d - distance between electrodesV = φ(d)V’ - ionization potential

Mechanism of Electric Actuation

w.wang 236

Silicone film

Au sheet

Glass substrate

Plastic filmGel

Au sheets

(a) Schematic diagram (b) Top view of coated gel

PVA gel actuator as a switch

w.wang 237

GelDMSO

Pupil

Application potential

w.wang 238

2mm60 ms

Carnivorous Plants

Application potential

w.wang 239

+ +

++

+

+

+

+

+ +

+++

++

++

+

++

++

+

+ +

++

+

++

+

+

+

– + – +Cu

Cu2+ + 2e-

Cu2+ + 2e-

Cu

Redistribution of ions

Electric current is charge current alone

Ion flux with electrode reaction

Electric current continuously flow

Static ion flux Dynamic ion flux

2 types of ion flux through membrane

2e-2e-E E

No current With current

+ Na+

+ Cu2+

Cu metalPt--Cu electrode

Pt or Au electrode

+

++

+

++

++

M. Uchida, CIMSUniversity of Washington

w.wang 240

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0 2 4 6 8 10 12Time ( sec )

curv

atur

e ( 1

/mm

) Pt-Cu

Pt-Li

Pt-Cu electrode with copper ion

Pt electrode with Lithium ion

Comparison with Pt electrode

V=1V

w.wang 241

7.8 µm

Nafion 117

After 2 plating cycles

6.1 µm

Nafion 115

Nafion 112

7.5µm

8.2 µm

16 µm

After 3 and 6 plating cycles

Material design: membranes of different thickness and gold electrodes

How it works?Nafion actuator array

The depth of the fractal structure is mostly controlled by the plating conditions not by the amount of gold.

w.wang 242

0

1

2

3

4

5

6

7

0 1 2 3 4

Displacement d (mm)

Forc

e F

(mN

)

1.0 V

0.5 V

(a)

Off

On

5mm

F

dOff

On

(b)

(c)

Off

On

5mm

F

d

Nafion loop actuator and performance data

w.wang 243

0123456789

10

0 1 2 3 4 5

Displacement ( mm )

Forc

e ( m

N)

1.0 V0.5 V

OFF Positive (expand) Negative (Shrink)

Parallel device

w.wang 244

Summary

Material Advantages DrawbacksAAm Large swelling ratio Low stiffness

Slow responsePAN Faster response Limited voltage range

Higher stiffnessPVA Fast response

Large deformation Low stiffnessLarge voltage range

Nafion Fast responseHigh stiffness

AAm - acrylamide basedPAN - polyacrylnitrilePVA - polyvinylalcohol

• Actuation materials

w.wang 245

Smart System option with PAN fibersConcept

5V, 0.5A

Counter electrodeMetal

Coated PANfibersshrink

water

positive electrode: H+ is created>acid condition, PAN fibers contract

negative electrode: OH- is created>basic condition, PAN fibers expand

Bundle of PAN fibers = muscle

Articulated rigid structure = bone

Assembly of articulated bones and contractile actuators creates a conformable fin. Many shapes are achievable.

Metal coatedPAN fibers expand

5V, 0.5A

Example of possiblefin design

Smart System option with PAN fibersConcept

5V, 0.5A

Counter electrodeMetal

Coated PANfibersshrink

water

positive electrode: H+ is created>acid condition, PAN fibers contract

negative electrode: OH- is created>basic condition, PAN fibers expand

Bundle of PAN fibers = muscle

Articulated rigid structure = bone

Assembly of articulated bones and contractile actuators creates a conformable fin. Many shapes are achievable.

Metal coatedPAN fibers expand

5V, 0.5A

Example of possiblefin design

Smart system option with PAN fibers concept

w.wang 246

Smart system option with PAN fibers concept: mimic nature!

from www.kidshealth.org/misc_pages/bodyworks/bodyworks.htmlfrom www.kidshealth.org/misc_pages/bodyworks/bodyworks.html

w.wang 247

Applications potential

Artificial tactile feel display

Tadokoro et al.Kobe University, Japan

w.wang 248

ApplicationsCharacteristics of IPMC

Low voltage ~1VBending mode of actuationLarge displacementSoftWetIonic natureSmall scale

ApplicationsMicropumpCatheterRobotfish actuatorGripper

www.eamex.co.jp/index_e.html

www.eamex.co.jp/index_e.html

www.eamex.co.jp/index_e.html

w.wang 249

Fleminon Fish

www.eamex.co.jp/index_e.html

w.wang 250

Applications

http://bifano.bu.edu/tgbifano/Web/%B5Valve.html

www.sciam.com

Actuator arrays

http://voronoi.sbp.ri.cmu.edu/projects/prj_virtualvehicle.html

Electroactive polymer actuator arraysLow cost, low power consumption, large displacement, softnessPolymer nature, compatible with wet environment

w.wang 251

How it works?Flemion actuator array

Actuator design: Flemion beam actuator for microwave switch

Microwave switch

Switch design: actuator above board and lifting contact pad in OFF stage. Contact pad resting against the TL in ON stage

TL

Transparency with copper pad

Actuator

tieWith additional weight

OFF stage

ON stage

Transmission lineContact pad

Actuator

ONOFF

w.wang 252

Actuator Array

Application: Antenna for satellite based Internet connection

Microwave switches

Nafionmembraneactuator

Dielectric Material

Waveguide

Nafion membraneactuator

wave

Phase Shifters

gap

How they work?

w.wang 253

3x3 Array from Nafion 112 with gold electrodesand TEA ion: Patterning

We use hydrophobic masks to selectively swell the membrane with the gold complex

Gold Phenantroline complex[Au(Phen)Cl2]+

ReductantNa2SO3

Gold metal platedat the surface

Gold is plated by reduction of the gold complex

Silicon rubber mask Gold

complex solution

Nafion membrane

w.wang 254

-3-2-10123

1 6 11 16 21 26 31

Vol

tage

(V)

-0.2

-0.1

0

0.1

0.2

curre

nt (A

)-0.2

0

0.2

0.4

0.6

1 6 11 16 21 26 31D

ispl

acem

ent (

mm

)

Voltage, current and displacement versus time of the active celldownward

profile

actuation

relaxation

initial profile

upwardprofile

actuation

relaxation

How it works?

w.wang 255

At time = 0secVoltage goesfrom 0 to 2V

Application: Conformable fin for Submarine

0.7s 2s0s

2s

2s

5s

5s0s180 micron thick

125 micron thick

50 micron thick

Nafion is an Ion Exchange Polymer Membrane. Negative charges are attached to the polymer backbone. Next to each negative charge is a positiveCounter ion and some water molecules. If we apply an electric field across Nafion the positive ions move and the whole membrane starts moving. This works best if the membrane is fully hydrated. Therefore Nafion actuators work best in water

How they work?

w.wang 256

Carbon nanotube actuator4V, strain 0.8%, stress 512GPa Baughman et al. Science 284(5418),1999

Wallace et al, 2001,SPIE

0

w.wang 257

Conducting Polymers

• Insulating polymers: familiar uses include cable sheathings, dielectric layers and films as in capacitors, printed circuit substrates.

w.wang 258

Conduction mechanisms

Conduction band

Valence band

Forb

idde

n ga

p

Ene

rgy

Conductor Semiconductor Insulator

hole

electron

Representation of energy band for metal semiconductor and insulator

w.wang 259

108

106

104

102

100

10-2

10-4

10-6

10-8

10-10

10-12

10-14

10-16

met

als

sem

icon

duct

ors

insu

lato

rs

GraphiteCopperIron, mercuryCarbon black

germanium

silicon

Silver bromide

glass

diamond

nylonsulphurpolyethylene

Poly

acet

ylen

ean

d de

rivat

ives

Poly

(p-p

heny

lene

) der

ivat

ives

Poly

phen

ylen

esu

lphi

dede

rivat

ives

Poly

pyro

lede

rivat

ives

Car

bon

blac

k co

mpo

site

s

Poly

mer

met

al c

ompl

exes

Poly

imid

e de

rivat

ives

phth

aloc

yani

nes

Conductivities of various elements, compounds and polymers

(Sm-1) Conductive polymers

w.wang 260

PolyPyrolysis

O

O

O

O n

w.wang 261

Polyacetylene

H-C=C-H

150Co

-78Co C CH

C CC C

C C

H

H

H

HH

HH

CC

CC

CC

CC

H

H

H

HH H

cis

trans

w.wang 262

Difference structure between polyethylene and polyacetylene

(a) Polyactylene thin film

(b) Polyactylene thick film

Polyethylene

Polyacetylene

ethyleneethylene

acetylene

w.wang 263

How they work?SP3

π-bond σ-bond

π-bond

(a)

(b)

C-C double bone

Polyactylene

Polyethylene

w.wang 264

Polyacetylene after doping

w.wang 265

Polyparaphenylenes

n

AlCl3, CuCl2

35 oC

w.wang 266

Polypyrrole

N

N

N

N

H

H

H

H

w.wang 267

PolyanilineNH

NH

NH

S S S

Polyphenylene sulfide

w.wang 268

Active drug delivery system and actuator

BB

B

B

stimulus+

-

B

B

B

B

Wallace et al, 2001,SPIE

w.wang 269

Wet-spun polyaniline (PANI) fiber

Cross-section micro-structure

Sensing fiber

Yang et al. 2001

w.wang 270

Clothing technology

w.wang 271

Applications of EC Polymer

Present Commercial Products:

• Plastic rechargeable batteriesPolyactylenes (PA) and polyanilines (PAn)cell phone, back-up power source for personal computer,solar-powered calculator etc

• SensorsPolypyrrole (PPy), PA, Polythiophone, Polyparaphenylenes (PPP) and PAnSensing vapours of nitromathane, toluene, benzene, methanol and waterDetermining the concentration of ions in solutionElectrochemical biosensors

•Shielding PAn etcElectrostatic discharge and electromagnetic interference/ratio-frequencyinterference applications

w.wang 272

Applications of Conductive Polymer

• Printed circuit boardsFlexible insulating substrate with a conducting pattern that could form the basis of printed circuit boardComplex multilayer board

• Condenser

• Various semiconductor devices

• Electrochromic displays, smart window

• Solid electrolyte (doped polypyrrole) and etc

w.wang 273

Applications of EC Polymer

Present research

• Diode

• Display for mini television

Future

• ElectronicsMolecular diode, molecular computer and electroluminescence and etc.

w.wang 274

Design of smart window technology

w.wang 275

Outline

1. Background2. Color changeable gel3. New design of electrochromic color changeable device4. Mechanism for color change 5. Preparing three parts for the device 6. Assembly7. Testing and analysis of performance

• Transmittance• Optical switching speed• Repeatability (Electrochemistry study)• Voltage effect on color change speed• Voltage effect on color change degree• Temperature dependence

8. Application potentials

w.wang 276

Liquid crystal

LiquidDifficulty in processing

Very fastMany colors

High costSmall size

Narrow angle

Background

long-term stability rapid switching large changes in transmittance

Polymer gels

Electrochromic(EC) polymer

?

Inorganic electrochromic

materials e.g. WO3

Liquid and solidDifficulty in processing

SlowBlue

Low costBig size

Wide angle

w.wang 277

A

A

A

AA

A

A

A

A

A+

A+

A+A+

A+

A+

A+

A+

A+ H2O

H2O

H2O

H2OH2O

H2O H2O

H2O

H2O

Machanism for color and volume change of copoly(Aam/vdMG) gel under UVor pH(Electric current)where A and A+ represent the neutralized and the ionized vdMG, respectively

C(H3C)2N

OH

N(CH3)2 C+(H3C)2N N(CH3)2

UVor E

+ OH-

～ ～

dark or E

10ｍｍ

Changing concentration of vdMG in the gel to control the degree of color change, color changedunder E-current, 1.5A,5V at 20 oC

w.wang 278

RESULTS AND DISCUSSION

• Color change speed

stimuli UV pH E-current UV & E-current E-current & Na2SO4 E-current & AAm gel

light green to dark green 3 min 1.5 min 40 s 30 s 23 s 19 sdark green to light green 15 h 2min 60 s 60 s 23 s 19 s

Previous results, Irie et al. present results

• Effect of gel thickness on actuation speed under applied E-currentEmployed the most effective setup given in above

thickness 1.0mm 0.75mm 0.50mm 0.25mm 0.125mm

light green to dark green 25s 19s 15s 11s 9sdark green to light green 25s 19s 15s 11s 9s

w.wang 279

Schematic diagram of device design using color changeable EC polymers

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Transparent Colored

Three-layer scheme:

Two-layer scheme:

Cathodic EC Polymer

Solid electrolyte

ITO

counterelectrode

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

counterelectrode

Transparent Colored

w.wang 280

Schematic diagram of mechanism for color change of cathodic EC polymer, PProDOT-Me2

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

OO

S

OO

S

OO

S

OO

Sn

O

S

OO

S

OO

S

OO

Sn

O

S

OO

S

OO

S

OO

Sn

O

S

OO

S

OO

S

OO

Sn

- -- --e -

+ e-

- -Dark blue

Neutral state

Transparent

p-Doped state

Au-patterned thin layer

+

ClO4- ClO4

- ClO4-

+ + - - -

Li+ Li+ Li+

Li+ Li+ Li+ ClO4- ClO4

- ClO4-

- +

Cathodic EC polymer

gel gel

w.wang 281

Schematic diagram of device design using color changeable EC polymers

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Transparent Colored

Three-layer scheme:

Two-layer scheme:

Cathodic EC Polymer

Solid electrolyte

ITO

counterelectrode

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

counterelectrode

Transparent Colored

w.wang 282

S

MeO OMe

+

OH OHpTSA

Toluene110 o C overnight

S

O O

ProDOT -Me 2

for Cathodic EC Polymer

S

MeO OMe

+

OH OHpTSA

Toluene110 o C overnight

S

O O

S

MeOMeO OMeOMe

+

OHOH OHOHpTSA

Toluene110 o C overnight

S

O O

Synthetic Route of Monomer,ProDOT -Me 2

for Cathodic EC Polymer

w.wang 283

-1.000.001.002.003.004.005.006.007.008.009.00ppm

1

2

3

S

O O

1

23

NMR spectra of cathodic monomer, ProDOT-(CH3)2

The number given over each NMR spectrum peak corresponds to the number given to the proton of ProDOT-(CH3)2 as shown in the left

w.wang 284

Synthetic Route of EC Monomer, XDOPSynthetic Route of EC Monomer, XDOP-Benzylation of Dimethyl Iminodiacetate

N

Ph

MeO2C CO2Me

NH

HO2C CO2H NH

CO2MeMeO2C

OO

OMeMeO

N

OHOH

CO2MeMeO2C

Ph

MeONa

53 4

1

Benzyl Bromide

2

+

MeOH

w.wang 285

OHHO

N CO2MeMeO2C

BrBr

O

N CO2MeMeO2C

OO

N CO2MeMeO2C

H

OO

N COOHHOOC

H

OO

N

H

Br Br

MsO OMs

O

Ph

+

Ph

6a

6b

6c5

7 a8a

9a 10a

Synthetic Route of EC Monomer, EDOP

w.wang 286

Synthetic Route of EC Monomer, ProDOP-(CH3)2

OHHO

N CO2MeMeO2C

BrBr

N CO2MeMeO2C

OO

N CO2MeMeO2C

H

OO

N COOHHOOC

H

OO

N

H

Br Br

MsO OMs

OO

Ph

+

Ph

6a

6b

6c5

7c8c

9c 10c

w.wang 287

Schematic diagram of device design using color changeable EC polymers

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Transparent Colored

Three-layer scheme:

Two-layer scheme:

Cathodic EC Polymer

Solid electrolyte

ITO

counterelectrode

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

counterelectrode

Transparent Colored

w.wang 288

PMMA based gel electrolyte for EC smart windows

PMMA/LiN(CF3SO2)2/PCwt% 20/10/70

PMMA/LiN(CF3SO2)2/PC+ECwt% 20/10/70 (PC:EC=1:1 on volume)

PMMA/LiClO4/PC+ECwt% 15/5/80 (PC:EC=1:1 on volume)

PMMA/LiClO4/PCwt% 20/10/70

w.wang 289

89.1 88.8 88.6 90.4 88.3 87.4 88.4 89.6 89.4 89.7

0

10

20

30

40

50

60

70

80

90

100

EC+PC/LiN(S

O2CF3)2

8/14

/02

ACN/LiN(S

O2CF3)2

8/14

/02

EC+PC/LiN(S

O2CF3)2

5/6/0

2

1 CLE

AR GLASS SLID

E

ACN/LiN(S

O2CF3)2

5/2/0

2

EC+PC/LiClO

4 8/21

/02

ACN/LiClO

4 8/19

/02

GBL(40m

l)+PC/Li

N(SO2C

F3)2 9/

21/02

GBL(20m

l)+PC/Li

N(SO2C

F3)2 9/

25/02

GBL(20m

l)+PC/Li

ClO4 9

/26/02

Electrode

% T

rans

mitt

ance

Transmittance of Indicated Gel ElectrolyteTransmittance of Indicated Gel Electrolyte

w.wang 290

Schematic diagram of device design using color changeable EC polymers

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

ITO

Transparent Colored

Three-layer scheme:

Two-layer scheme:

Cathodic EC Polymer

Solid electrolyte

ITO

counterelectrode

Cathodic EC Polymer

Solid electrolyte

Anodic EC Polymer

ITO

counterelectrode

Transparent Colored

w.wang 291

GlassDiameter 4 inch

Top View

Side View CarbonITO

Glass

Design of Pattern for Carbon and GoldBased- Counterelectrode

(b) Au-based(a) Carbon-based

w.wang 292

0

10

20

30

40

50

60

70

80

90

100

Au

50µ1

.5

Au

100µ

1.5

Au

25µ1

.5

Au

15µ1

.0

Au

50µ2

.5

Hita

chi g

lass

C 6

µ0.1

C 2

0µ1.

0

C 2

0µ1.

5

C 2

0µ2.

0

C 6

µ1.0

C 6

µ1.5

C 1

0µ1.

5

Electrode

% T

rans

mitt

ance

Transmittance of Indicated ElectrodeTransmittance of Indicated Electrode

w.wang 293

Transparent insulating substrate

ITO transparent film

EC polymer film

Transparent gel electrolyte

Carbon patterned thin layer

ITO transparent film

Assembly of EC polymer device for transmittance control in visible region, carbon-based

counterelectrode

w.wang 294

Assembly of EC polymer device for transmittance control

in visible region, Au-based counterelectrode

Transparent insulating substrate

ITO transparent film

EC polymer film Transparent gel electrolyte

Au patterned thin layer

w.wang 295

Color Change of EC Polymer Device Using Au Patterned glass as a Counterelectrode

(a) 2.5V, Transparent (b) - 2.5V, Dark blue

1s

w.wang 296

Color Change of EC Polymer Device Using Graphite Patterned ITO glass as a Counterelectrode

(a) 2.5V, Transparent (b) - 2.5V, Dark blue

1s

w.wang 297

010

2030

4050

6070

8090

190 290 390 490 590 690 790

Fully reducedFully oxidized

Tra

nsm

ittan

ce/%

Enhanced Contrast Ratio in Cathodic EC Polymer Device Based on Au patterned counterelectrode

Wavelength/nm

Visible spectrum collected in transmittance mode of a cathodicEC polymer device in fully transmitted and fully colored states

Bleached

Colored

w.wang 298

Enhanced Contrast Ratio and Rapid Switching in Cathodic EC Polymer Device

Optical switching for the devices based on indicated counterelectrodes monitored at wavelength 580nm

(a) Au-based

(b) Carbon-based

w.wang 299

Photographs of potential effect on color changing degree

Color changing speed is same, less than 1s

0V -1.0V -1.5V -2.0V - 2.5V

-0.15V -0.2V -0.25V -0.3V - 0.35V

Blue EC polymer device/Gold

counterelectrode

Red EC polymer/ITO glass

w.wang 300

Original Blue New Blue

Blue EC Film ComparisonBlue EC Film Comparison

w.wang 301

New red color

w.wang 302

10a

w.wang 303

10c best

w.wang 304

A circular smart window with rubber seal

Carbon patterned ITO glass

+

_+_

EC polymer deposited ITO glass

Sealing rubber

Gel electrolyte

Smart window

w.wang 305

A simple electrochromic display

An electrochromic window

Ishihara et al ,2001

w.wang 306

Application Potential

Commercial air plane Special air craft

http://www.boeing.com

w.wang 307

Smart window

http://windows.lbl.gov/materials/chromogenics

w.wang 308

Future works

Several new ideas…

1. Carbon nanotube actuator

2. Conducting polymer• Bio-related actuator drug delivery system, e.g. polypyrrole• Sensing clothing Body stress, signal, e.g. polyaniline(PANI) fiber

3. Special fiber

w.wang 309

All-solid-state Electrochromic GlazingWO3, high durability but low contrast ratio (40:1)

F. Beteille (France) The SPIE Conference on Switchable Materials and Flat Panel DisplaysSPIE Vol. 3788 pp.70-73 (July 1999)

Aircraft side window

w.wang 310

E-ink

How they work?

Scientific American November 2001 pp,51-54

w.wang 311

Flexible active-matrix electric ink display

- Electric paper

White state Dark state

Nature 136 p.136 (2003)

w.wang 312

Shape memory polymer

w.wang 313

Camouflage skin of Octopus

Camouflaged in whiteOriginal

w.wang 314

Day timeLand warrior

Day timeTaking a break

NightMoving to the position

Application potential--- Wearable smart sensors/actuator

w.wang 315

Conclusions• From “hard” to “soft” technology

• EAP - structure, processing, sensing, actuation……all in one

• Advantages for actuator applications:- light weight- energy storage- viscous damping- low cost

• Challenges:- Materials development- Integration into smart devices and structures