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
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