Design and characterization of polymeric domes as biasing elements for dielectric elastomer membrane actuators

Dielectric elastomer actuators (DEAs) consist of an elastomer membrane in between two compliant electrodes. When the actuator is mechanically biased by a suitable system (e.g., a spring or mass), it is possible to control the membrane displacement by applying a high voltage to the electrodes. Despite most of the existing actuators operate in the macro-scale, providing strokes in the range of centimeters, DEA technology also has a high potential for micro-scale devices. Common metal-based biasing springs used in macro-scale DEAs, however, are not suited for micro-fabrication methods and miniaturized applications in general. In this work, we present a new design solution for DEA biasing system, consisting of compliant polymeric domes. The new solution has great potential for further downsizing as well as for emerging applications such as wearables and soft robotics. After describing the manufacturing process, polymeric domes of different geometries are realized and tested. Their force-displacement characteristics is then evaluated in order to investigate the influence of different design parameters on the corresponding curves.