Effect of Different Electrode Materials on the Performance of Smart Composite Actuators Based on Dielectric Elastomers

Abstract

Dielectric elastomers are a class of electro-active polymers (EAPs) which have great potentials to be used in smart composites. These materials with compliant electrodes are converters of electrical energy to mechanical energy in order to produce external load and strain with good efficiency. Electrode materials should typically have good compliancy so that undergo large strain alongside the film, without producing any additional stress and constraint for the actuator. In the present study, the effect of 4 different electrode materials (graphite filled silicone oil, silver filled grease, graphite powder and electrically conductive silicone rubber) on the performance of dielectric elastomer actuators has been studied. The principle of operation, the method of fabrication and test method of planar actuators are discussed. We have also studied the effects of different driving voltages and different prestrain values on the actuator response. Experimental results showed that electrical conductivity, material compliancy, and compatibility with substrate in the electrode materials are some of the important parameters affecting the actuator performance.