Material platform for dielectric elastomer actuators - important properties of the investigated material and long-term stability characteristics of the actuator layers

Abstract

This paper will show a conceptual new material platform for dielectric elastomer actuators (DEA). The working principle of DEAs is based to the displacement of a flexible insulating dielectric which is placed between two electrodes. If an electrical voltage is applied, an electrostatic pressure will be generated, which forces the elastic material to stretch. State of the art actuators exhibit non-flexible metallic or graphite electrodes. The difference in flexibility leads to material incompatibilities and reduces the durability and long-term stability of actuator assemblies. The new material platform consists of only one basic polymer for all layers. Ceramic fillers were used to obtain a higher permittivity of the dielectric layer. The electrode layer was modified with nanoscale fillers like Carbon Nanotubes (CNT) to reach the needed specific conductivity. The newly developed material and actuator platform showed outstanding results regarding displacement, durability and long-term stability. The durability and long-term stability were demonstrated successfully using several mechanical and electro-mechanical stress tests with up to millions of load cycles