Electro-active polymer actuators employing sulfonated poly(styrene-ran-ethylene) as ionic membranes

Abstract

We first investigated sulfonated poly(styrene-ran-ethylene) (SPSE) as a novel ionic membrane for electro-active polymer actuators. SPSE is a newly developed hydrocarbon ionomer synthesized through a post-sulfonation procedure. The thermal, electrical, morphological and mechanical properties, as well as ion-exchange capacity, proton conductivity and water uptake were investigated and compared to a Nafion (R) counterpart. Tensile tests revealed that the SPSE membrane has good mechanical stiffness and strength while immersed in water. SPSE copolymers have good thermal stability and are easily processed for the production of membranes. In this study, SPSE actuators were fabricated according to traditional ionomeric polymer-metal composite preparation procedures and tailored to moderate dimensions. The bending responses of the SPSE actuators under both AC and DC electric excitations were investigated. The voltage-current behaviors of the actuators under AC excitation were also measured. The results showed that the SPSE actuators have good electromechanical performance with regard to tip displacement. (C) 2010 Society of Chemical Industry