Universidad Politécnica de Cartagena REACTIVE CONDUCTING POLYMERS AS ACTUATING SENSORS AND TACTILE MUSCLES Toribio Fernández Otero Centro de Electroquimica y Materiales Inteligentes (CEMI) www.upct.es/electroquimica/laboratorio
BIOMIMETICS, 07 Full Range of Sizes Sixty Sixty Orders rders of of Magnitude agnitude Life Life in Middle in Middle Region Region Radius of Visible Planck Length Universe Amoeba 10 -35 m Man 10 26 m 10 -5 -10 -4 m 10 0 m Good physical models for very small or very large systems. Bad description of the intermediate systems: complexes molecular interactions and shifts on those interactions (life)
BIOMIMETICS, 07 Conducting Polymers Conducting Polymers 2000 Nobel Award in Chemistry 1977 JCS Chem. Comm. 578-580 “ for the discovery and development of conductive polymers" Hideki Shirakawa Alan GMacDiarmid Alan J Heeger
BIOMIMETICS, 07 Polypyrrole Oxidized polypyrrole - 2 e − H H H H H H N N N N N N N N N N H H H H n n Swelled Compacted THE OXIDATION induces : - Breaking of double bonds - Conjugation - New double bonds. - Conformational changes - Soft and back field ionic implantation
BIOMIMETICS, 07 REVERSE ELECTROCHEMICAL OXIDATION/REDUCTION (SWELLIN/SHRINKING) OF A CONDUCTING POLYMER FILM Polypyrrole film Metal: electric contact Aqueous solution www.upct.es/electroquimica/laboratorio
BIOMIMETICS, 07 ELECTRO-CHEMO-MECHANICAL DEVICES: SHIFTING ACTUATING MOLECULAR INTERACTIONS DURING THE REACTION. THE DRIVING ELECTROCHEMICAL REACTION PROMOTES A CHANGE OF THE INTERMOLECULAR INTERACTIONS INSIDE THE FILM: -POLYMER-POLYMER -POLYMER-COUNTERION -POLYMER-SOLVENT -SOLVENT-IONS
Universidad Politécnica de Cartagena BIOMIMETICS, 07 Center for Electrochemistry and Intelligent Materials (CEIM) (CEMI) www.upct.es/electroquimica/laboratorio reduced chains ↔ reduced chains ↔ neutral chains ↔ neutral chains ↔ oxidized chains oxidized chains n doping n doping (a) (b) p doping (a) (b) p doping THE OXIDATION OF A CHAIN OCCURS THROUGH CONSECUTIVE STEPS THE OXIDATION OF A CHAIN OCCURS THROUGH CONSECUTIVE STEPS CP, (CP + )A - , (CP 2+ )A - CP, (CP + )A - , (CP 2+ )A - 2 , (CP 3+ )A - 2 , (CP 3+ )A - 3 , (CP 4+ )A - 3 , (CP 4+ )A - 4 , (CP 5+ )A - 4 , (CP 5+ )A - 5 , (CP 6+ )A - 5 , (CP 6+ )A - 7 ,..., (CP n+ )A - 7 ,..., (CP n+ )A - n n EVERY STEP IS A CHEMICAL EQUILIBRIUM EVERY STEP IS A CHEMICAL EQUILIBRIUM [(pPy n+ ) s (Cl - ) n (H 2 O) m ] gel + (Cl - ) aq + aH 2 O [(pPy n+ ) s (Cl - ) n (H 2 O) m ] gel + (Cl - ) aq + aH 2 O ↔ ↔ [(pPy (n+1)+ ) s (Cl - ) n+1 (H 2 O) m+a ] gel + (e - ) metal [(pPy (n+1)+ ) s (Cl - ) n+1 (H 2 O) m+a ] gel + (e - ) metal DEFINING AN ELECTRODIC POTENTIAL DEFINING AN ELECTRODIC POTENTIAL E = k 1 /k -1 = E 0 - RT/F ln [(pPy (n+1)+ ) s (Cl - ) n+1 (H 2 O) m+a ] / [(pPy n+ ) s (Cl - ) n (H 2 O) m ] [Cl - ] E = k 1 /k -1 = E 0 - RT/F ln [(pPy (n+1)+ ) s (Cl - ) n+1 (H 2 O) m+a ] / [(pPy n+ ) s (Cl - ) n (H 2 O) m ] [Cl - ]
BIOMIMETICS, 07 STRUCTURE FOR AN IDEAL, MIMETIC (ARTIFICIAL) AND NANOMETRIC SARCOMERE Polymeric chains Polymeric chains Polymeric chains Polymeric chains Conducting material Conducting material Conducting material Conducting material
BIOMIMETICS, 07 Artificial Muscle for a conscious system Electric pulses generator Signals control WE CE RE Two wires driving signals anode anode cathode Volume variations cathode Conformational changes non conducting Ppy films film Ionic interchanges Water interchange Li + ClO 4 - Mechanical stress and work
(pPy)s + n(Cl-)aq + mH2O ↔ [(pPyn+)s(Cl-)n (H2O)m]gel + (n e-)metal (Volume)1 (conc. and I) T (Volume)2 i and E (synthesis contitions) BIOMIMETICS, 07 Muscle potential Evolution of the muscle potential Influence [Electrolyte] Under different current flow i = 10 mA 2 5mA 10mA 15mA 2 20mA 25mA E / V E / V 1 1 [1M] [0.8M] [0.6M] [0.4M] [0.2M] 0 0 0 5 10 15 20 25 30 0 10 20 30 40 50 t / s t / s
BIOMIMETICS, 07 3 2 0 3 2 0 3 0 0 3 0 0 ACTUATORS 2 8 0 2 8 0 Ee/mJ Ee/mJ AND 2 6 0 2 6 0 SENSORS 2 4 0 2 4 0 2 2 0 2 2 0 0 . 0 0 . 0 0 . 2 0 . 2 0 . 4 0 . 4 0 . 6 0 . 6 0 . 8 0 . 8 1 . 0 1 . 0 1 . 2 1 . 2 [Electrolyte] [ L i C [ L i C l O l O 4 ] / M 4 ] / M b ) b ) 3 5 0 3 5 0 3 0 0 3 0 0 2 5 0 2 5 0 Ee/mJ Ee/mJ 2 0 0 2 0 0 1 5 0 1 5 0 1 0 0 1 0 0 0 0 5 5 1 0 1 0 1 5 1 5 2 0 2 0 2 5 2 5 3 0 3 0 Current I / m I / m A A c ) c ) 2 9 4 2 9 4 2 9 2 2 9 2 2 9 0 2 9 0 2 8 8 2 8 8 Ee/ mJ Ee/ mJ 2 8 6 2 8 6 2 8 4 2 8 4 2 8 2 2 8 2 2 8 0 2 8 0 2 7 8 2 7 8 Trailed weight 0 0 6 0 0 6 0 0 1 2 0 0 1 2 0 0 1 8 0 0 1 8 0 0 2 4 0 0 2 4 0 0 3 0 0 0 3 0 0 0 o b s t a c l e w o b s t a c l e w e i g h t / m e i g h t / m g g
BIOMIMETICS, 07 TOUCHING, PUSHING, AND SENSING MUSCLE 8s 15 mA Device: 2 x 1 cm 2 8s -15 mA Adv. Mat. 15, 279-282 (2003)
BIOMIMETICS, 07 (Advancing) (Contact) (Pushing) 0.6 0.4 0.2 E / V 0 0 50 W -0.2 100 W 160 W 180 W -0.4 200 W 1200 W -0.6 0 10 20 30 40 50 t / s
BIOMIMETICS, 07 COMPLEXES STRUCTURES KEEP SIMULTANEOUS ACTUATING-SENSING RPOPERTIES: ROMBIC DEVICE BY COMBINATION OF BILAYERS INCLUDING: WE, RE and CE J. Bioelectrochem. Bioenerg., 38, 411-414 (1995) J. Appl. Electrochem., 36, 205–214 (2006) J. Bioelectrochem. Bioenerg., 42, 117 - 122 (1997)
BIOMIMETICS, 07
BIOMIMETICS, 07
BIOMIMETICS, 07 LARGE (40%) LONGITUDINAL MOVEMENT PATENT:P200300800 40% Δ l 8s 15 mA Devices: 2 x 1,5 cm 2 8s Electrochim. Acta (2007) -15 mA
BIOMIMETICS, 07 Monodimensional combination of devices (In progress) For strong mechanical developments For large displacements
BIOMIMETICS, 07 MUSCLE ELEMENT IN THREE DIMENSIONS (In progress) Able to save internal electrical interruptions
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BIOMIMETICS, 07 MOLECULAR MOTOR: IDEAL, LINEAL CHAIN OF A CP GRAFTED TO AN ELECTRODE METAL METAL SOLUTION SOLUTION CONFORMATIONAL MOVEMENTS ORIGIN OF ACTUATING AND SENSING PROPERTIES PROBLEM: CHARACTERIZATION??? SOLUTION: THE CONFORMATIONAL ENERGY !!! QUESTION: IS THIS ENERGY AN ACTIVATION ENERGY ?? OF THE STIMULATING ELECTROCHEMICAL REACTION
P o ly m e r ic C h a in P o ly m e r ic C h a in P o ly m e r ic C h a in BIOMIMETICS, 07 A n io n s A n io n s A n io n s F u ll o x id a t io n F u ll o x id a t io n F u ll o x id a t io n u n d e r d if f u s io n c o n t r o l u n d e r d if f u s io n c o n t r o l u n d e r d if f u s io n c o n t r o l P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r P a r tia l o x id a tio n u n d e r r e la x a tio n r e la x a tio n r e la x a tio n r e la x a tio n r e la x a tio n r e la x a tio n r e la x a tio n r e la x a tio n c o n t r o l c o n t r o l c o n t r o l c o n t r o l c o n t r o l c o n t r o l c o n t r o l c o n t r o l 2 2 0 0 2 2 0 0 2 0 0 0 2 0 0 0 1 8 0 0 1 8 0 0 C o m p a c te d P o ly m e r C o m p a c te d P o ly m e r C o m p a c te d P o ly m e r R e la x a tio n R e la x a tio n R e la x a tio n S w e llin g S w e llin g S w e llin g 1 6 0 0 1 6 0 0 1 4 0 0 1 4 0 0 1 2 0 0 1 2 0 0 2 2 I/ μ A/cm I/ μ A/cm 1 0 0 0 1 0 0 0 8 0 0 8 0 0 6 0 0 6 0 0 4 0 0 4 0 0 E E c a t c a t 2 0 0 2 0 0 0 0 - 2 0 0 - 2 0 0 - 4 0 0 - 4 0 0 - 6 0 0 - 6 0 0 E / m V E / m V - 8 0 0 - 8 0 0 - 1 4 0 0 - 1 4 0 0 0 0 2 0 0 2 0 0 4 0 0 4 0 0 6 0 0 6 0 0 8 0 0 8 0 0 1 0 0 0 1 0 0 0 1 2 0 0 1 2 0 0 C o m p a c tio n C o m p a c tio n C o m p a c tio n S h rin k in g S h rin k in g S h rin k in g R e d u c tio n + c o m p a c tio n R e d u c tio n + c o m p a c tio n R e d u c tio n + c o m p a c tio n P a r tia l r e d u c tio n P a r tia l r e d u c tio n P a r tia l r e d u c tio n C lo s e d C lo s e d C lo s e d u n d e r r e la x a tio n c o n tr o l u n d e r r e la x a tio n c o n tr o l u n d e r r e la x a tio n c o n tr o l P o s itiv e s c h a r g e s o n P o s itiv e s c h a r g e s o n P o s itiv e s c h a r g e s o n S o lv e n t S o lv e n t S o lv e n t u n d e r d iff u s io n u n d e r d iff u s io n u n d e r d iff u s io n s tr u c tu r e s tr u c tu r e s tr u c tu r e M o le c u le s M o le c u le s M o le c u le s p o ly m e r ic c h a in s p o ly m e r ic c h a in s p o ly m e r ic c h a in s c o n tr o l c o n tr o l c o n tr o l
BIOMIMETICS, 07 Kinetic Control Control Kinetic β ,j exp ( α zF η /RT) i =k Π c j 1. Conformational Relaxation (ESCR) d c 2. Chemical control?? 3. Diffusion (ESCR) b a 1 2 3
BIOMIMETICS, 07 ELECTROCHEMICAL REACTIONS OF POLYTHIOPHENE IN PRESENCE OF THE SOLVENT S CONTAINING THE ANION A (pTh) s + n(A - ) solv + m(S) ↔ [(pTh n+ )(A - ) n (S) m ] gel + (n e - ) metal neutral chains oxidized chains OXIDATION EMPRICAL KINETIKS R = A exp( -E a /RT) [ClO 4 - ] α [pTh + ] β Log R = dQ / dt = i α log [C10 β log [ /RT)] + α - ] + ] + β n+ + ] Log i = log[A log[A exp( exp( - -E E a log [C10 4 4- log [pTh pTh n ] a /RT)] + This equation states the experimental procedure required to obtain: k, E a,, α and β .
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