The effect of electrode composition on partial discharge behavior in dielectric elastomers

Dielectric elastomers are a class of field-driven electroactive polymers which utilize a soft dielectric and compliant electrodes to couple electric fields to mechanical strains. As actuators, the charge stored on opposing electrodes generates a compressive force on the soft elastomeric dielectric, and when used as a generator, the changing capacitance resulting from cyclic stretching of the dielectric can be used harvest electric energy. In both cases, a major limiting factor to either the output force of an actuator or the energy per cycle of a generator is the maximum field strength across the dielectric. Other factors include the elastomer's dielectric constant and the stiffness both of the dielectric and of the electrodes. Material degradation due to partial discharges will lower the maximum voltage that can be applied to a dielectric elastomer system. The level of partial discharge activity should be understood for the various design decisions that are made for dielectric elastomer systems. This work will look at the role electrode composition may play in the partial discharge signature. This is recorded using a realtime characterization system to collect data during voltage cycling. In addition, the partial discharge activity detected in the elastomer system using rigid electrodes will be compared to the powdered complaint electrodes typically used for dielectric elastomers.