Electromechanical Properties of Poly(3,4-ethylenedioxythiophene)/Poly(4-styrene sulfonate) Films

Abstract

Free-standing films made of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrene sulfonate) (PEDOT/PSS) were prepared by casting water dispersion of its colloidal particles. Morphology, water vapor sorption, and electro-active polymer actuating behavior of the resulting films were investigated by means of atomic force microscopy, sorption isotherm, thermal mechanical analysis, and electromechanical analysis. It was found that the PEDOT/PSS film sorbed 60% of moisture at relative water vapor pressure of 0.95. Upon application of 10 V, the film underwent contraction of 2.4% in air at 50% relative humidity (RH) which significantly increased to 4.5% at 90% RH. The principle lay in desorption of water vapor sorbed in the film due to Joule heating, where electric field was capable of controlling the equilibrium of water vapor sorption. The film generated contractile stress as high as 17 MPa under isometric conditions and work capacity attained 174 kJ m(-3), where Young's modulus of the film increased from 1.8 to 2.6 GPa by application of 6 V at 50% RH.

High-ampacity conductive polymer microfibers as fast response wearable heaters and electromechanical actuators

“…Some other PEDOT based heaters, such as PEDOT/PSS film and PEDOT nanofiber mat, have a response time several times longer than our PE-DOT/PSS fibers due to their low conductivities. 11,51 The fast response of PEDOT/PSS fibers is ascribed to the small diameter and a direct measurement without any substrate attached to the fibers. To summarize, the merit of PEDOT/PSS fibers as heaters lies in (1) very fast response which is comparable with metal wires; (2) low density, high conductivity, high flexibility, stretchability and better tolerance to frequent bending and contact as compared to carbon fibers and metallic wires 54 ; and (3) good spinnability for directly co-spinning with nonconductive polyester fibers from different nozzles, which can be easily twisted and woven into textiles for the application of wearable heaters.…”

“…The conversion of electri-cal energy into thermal energy has been realized using PE-DOT/PSS microfilms or silver nanowire/PEDOT/PSS transparent nanofilms as heaters, although the heaters had slow response times (15-80 s). 11,12 Meanwhile, the conversion of electrical energy into mechanical energy has been widely investigated in PEDOT/PSS film or papers. The well-known actuation mechanism is strongly related to the highly hygroscopic nature of PEDOT/PSS.…”

“…Actuation in PEDOT/PSS-based devices thus results from an electro-thermal-mechanical coupling, a multiphysics nature that facilitates various actuation stimuli. 11,[13][14][15][16] For example, a (PEDOT/PSS)/elastomer bilayer actuator was developed to achieve a bending motion under multiple control stimuli, such as electrical current, heat and humidity changes. 17 To date, most research on PEDOT/PSS-based electroactive materials has focused on two-dimensional films or coated papers.…”

“…17 To date, most research on PEDOT/PSS-based electroactive materials has focused on two-dimensional films or coated papers. 11,14,15 Therefore, opportunities to design PEDOT/PSS fibers or wires for specific applications, such as functional textiles, or to increase their sensitivity in general remain outstanding. In a previous study, we investigated the electromechanical actuation properties of low conductivity (PEDOT/PSS)/polyvinyl alcohol fibers, which can generate a maximum actuation stress of 11 MPa at 8 V. 18 However, they feature a low response time (80 s), which leads to a slow stress generation rate (0.14 MPa s 1 ) and a narrow operating frequency window (< 1 Hz).…”

Preparation and Characterization of Poly(N-Methylpyrrole)/MoO3 Hybrid Composites

“…[4,5] Regarding to the energy storage applications, the most successful results have been achieved when PNMPy is combined with more electroactive materials, as for example copper nanoparticles [6] or layers of poly(3,4-ethylenedioxythiophene) (PEDOT), [7] a conducting polymer (CP) with outstanding properties. [8][9][10][11][12] Amazingly, the electrochemical and capacitive properties of electrodes made of alternated layers of PEDOT and PNMPy (PEDOT/PNMPy/PEDOT) were significantly better than those of PEDOT alone and PEDOT/PPy/PEDOT layers. [7,13] Among inorganic electrode materials, molybdenum trioxide (MoO 3 ) particles have been subject of increasing interest due to their high electrochemical activity and ecofriendly nature.…”