Design of Electrical Contact for DE Transducers under Thermal Considerations

Dielectric Elastomers (DE) have been reported to be a promising transduction principle for various applications, including loudspeakers. Here, high-frequency signals of several kilohertz at high voltage amplitudes of few hundred volts are fed into the DE, which forms a capacitor. Thus, Joule heat generation in the often carbon-black based electrode must be taken into account, especially since DE have been reported to show temperature dependent actuating performance. In this study different configurations of DE are examined by means of thermal imaging and the results are compared to analytical and numerical electrothermal models. It is shown that heat generation can be minimized by designing the electrical contact carefully and that imperfect electrical contacts can cause localized heat. The results will help developing robust loudspeakers and dynamic DE transducers in the future.