A Study on the Effect of Flexible Electrodes and Passive Layers on the Performance of Dielectric Elastomer Membranes

This paper investigates the effect of flexible electrodes and passive layers on the electromechanical performance of dielectric elastomer membranes. Four compliant electrodes were tested: carbon grease, silver grease, graphite spray, and graphite powder. The test setup consisted of a clamped diaphragm subject to an inflation pressure and an electric field. The electrode experiments show that both silver grease and carbon grease are the most effective electrodes of those tested. Passive layer tests were performed in three groups according to the position of the added layers relative to the actuator: (i) passive layer placed on top of the actuator, (ii) passive layer on the bottom of the actuator, and (iii) passive layers on both the bottom and top of the actuator. For the passive layer tests, the results show that adding elastic layers dramatically changes the mechanical response of the actuator but does not change the electrical response significantly. The ability to use capacitance measurements to determine the membrane's deformation state is investigated. The experiments demonstrate that capacitance measurements can indeed be used for mechanical sensing.