Modelling the performance of devices based on thin dielectric elastomer membranes

Abstract

Actuators based on thin dielectric elastomer (DE) membranes with very low modulus, high dielectric permittivity and dielectric breakdown strength have recently been used in a number of diverse applications. In order to be technologically viable, the fidelity of their responses, especially in operations over large number of cycles, and failure mechanisms need to be understood and modelled. We present a simple, uncoupled, explicit scheme for simulating actuators based on DE membranes that depends on a characterisation of the material as a electro-visco-hyperelastic one. Experimental charactersiation of the uniaxial viscoelastic stress strain response, stretch dependent dielectric permittivity and breakdown strength of a commonly used DE material has been carried out. The simulation methodology has been verified against the performance of a circular membrane based actuator subjected to a cyclic potential. The simulations reproduced the experimental responses well and also allowed us to computationally map out the parameter space for safe operation of the actuator.