Actuation abilities of multiphasic electroactive polymeric systems

Abstract

The need of low-cost, high-strain actuators has recently brought the attention on electroactive polymers. Specifically, a particular interest has been placed on dielectric-based electrostrictive polymers that are flexible, conformable, and with an easy manufacturing process. The purpose of this paper is to investigate the actuation abilities of such devices when several phases (i.e., dipolar and interfacial) contribute to the electroactive strain response. Based on a Debye-Langevin approach, the expression of each phase contribution will be investigated, and the response with several phase ratios discussed. In particular, it is shown that a trade-off exists between low electric-field response, where the main design parameter lies in the permittivity, and the high electric-field response, where a polarization saturation effect occurs that limits the electric-generated strain. In addition, it is shown both theoretically and experimentally that for a biphasic system, a particular crossing point appears in the strain response as a function of the electric field whatever the phase ratio, as well as in the frequency-domain electrical response.