Poly(3,4-ethylenedioxythiophene)-containing semi-interpenetrating polymer networks: a versatile concept for the design of optical or mechanical electroactive devices

International audienceThe synthesis of one-piece electronic conducting interpenetrating polymer networks is proposed as an alternative to multilayer architectures for the design of electroactive devices. The electronic conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as active component was symmetrically distributed in a solid polymer electrolyte (SPE) matrix based on poly(ethylene oxide) which was subsequently swollen with either LiClO4 or an ionic liquid. Depending on the composition and the crosslinking density of the SPEs, the ionic conductivities vary between 0.9 × 10−3 and 2.2 × 10−3 S cm−1 at 30 °C. Controlling the PEDOT content from 0.3 to 12 wt% in the material, electrochromic, electroemissive or electromechanical properties are obtained. Typical transmissive and reflective contrast values reach 33 and 27% at 630 and 2500 nm, respectively, for free-standing films upon application of a 1.2 V bias voltage. Both bending and linear actuating devices were developed as beam-shaped or hollow fibres. The actuation occurs under low applied voltage up to 4 V and the output force ranges from 50 to 300 mN. In all cases the electroactive properties are stable over 10 000 (electroemissivity) to 3.5 × 106 (actuation) cycles in open air providing an ionic liquid is used as electrolyte