Static and Dynamic Electro-Response of a Triblock Polymer Gel
Dielectric elastomers, a class of electroactive polymers, are specially promising due to their proven high actuation strain and energy density. Their electromechanical response is described by the Maxwell stress, where the level of strain reached depends mostly on the dielectric constant, elastic modulus and applied electric field. Since a decrease in modulus can enhance the elastomer response, swelling in appropriate solvents, transforming them into gels may enhance actuation. Tri-block copolymer gels offer a large range of possibilities since the mechanical properties and electroactive behaviour of these physically crosslinked materials can be adjusted by varying the polymer concentration, morphology and molecular weigh between crosslinks. In this work efforts were undertaken in reducing the elastic modulus by selective swelling of the elastomer midblocks with an organic oil. Strain responses to static and dynamic electrical stimuli were considered and, in particular, the effect of the frequency on the mechanical efficiency was investigated in detail. A simple theoretical model describing the frequency response was formulated.
Pietro VINCENZINI and Giuseppe D'ARRIGO
T. Leitão et al., "Static and Dynamic Electro-Response of a Triblock Polymer Gel", Advances in Science and Technology, Vol. 54, pp. 90-95, 2008