Design and simulation of negative-stiffness thermoplastic biasing mechanism for dielectric elastomer actuators

Abstract:
Dielectric elastomer actuators (DEAs) are soft transducers consisting of thin and highly stretchable polymeric membranes coated with compliant electrodes. DEAs can work in an out-of-plane configuration by properly coupling the membrane with a mechanical biasing system whose force-displacement behavior is designed to match the one of the dielectric membranes. In this paper we propose an approach for fabrication, modelling, and optimization of a DEA biasing system consisting of a thermoformed PET buckling beam. The buckling response of the PET beam presents a less hysteretic behavior than silicone-based counterparts, while still being based on polymeric material. To better design the biasing system with the goal of integration within a DEA, a finite element model and a geometric optimization routine are developed.