Suitability of Different Analytical Derivations of Electrically Induced Stress States in Planar and Cylindrical Dielectric Elastomer Actuators

Abstract

Dielectric elastomers (DE) belong to a very performant and efficient class of functional materials for actuators, while being compliant, low-weight and silent, they offer high energy efficiencies and large deformations under an applied electric field. In this work, a comparison of different approaches to derive expressions for the electrically induced stress states in dielectric materials is given. In particular, the focus is on three different ways to analytically describe stress states in planar actuator setups and to show how they are connected to each other regarding their resulting deformations. This is the basis to evaluate the suitability of these approaches for cylindrical actuator geometries together with exemplary calculations for concrete use cases. As an outcome, conclusions on the suitability of the different approaches for certain actuator setups are drawn. In particular cylindrical actuator geometries are taken into account and a recommendation on which approach is useful to describe a certain actuator effect is given.

Investigation of a Simple Viscoelastic Model for a PVC-Gel Actuator under Combined Mechanical and Electrical Loading

“…K. Asaka et al proposed an electromechanical model based on the electrochemical properties of PVC gels [ 6 ]. A comparison of the stored-energy approach, energy-balance approach, and Maxwell-stress-tensor approach to derive expressions for the electrically induced stress state in the dielectric material was made [ 11 ]. Based on the material properties of Young’s modulus and damping, Maxwell stress was applied to obtain the governing equations [ 12 ].…”