A Multi‐Mode, Multi‐Frequency Dielectric Elastomer Actuator

Abstract This paper presents a principle to develop multi‐function dielectric elastomer actuators (DEAs) that can concurrently accomplish linear actuation and sound generation through a single electrical input. A centimeter‐scale cone‐shaped DEA is fabricated using silicone‐based dielectric and electrodes. Measurements of the vibro‐acoustic response reveal that the pumping deformation of the DEA contributes to a negligible extent in the sound generation, which is hence ascribable to higher order structural modes whose frequency pass‐band is highly uncoupled from that of the pumping mode. Exciting the DEA with a multi‐chromatic input voltage allows achieving strokes close to 1 mm or blocking forces over 0.5 N, while simultaneously generating sound pressure levels over 60 dB, regardless of possible forces and/or mechanical constraints on the DEA pumping motion. The ability of the DEA to concurrently generate linear actuation and sound is demonstrated via proof‐of‐concept tests: the DEA can reproduce music, while at the same time generating a deformation pulse or lifting a load comparable with its own blocking force. Furthermore, measuring the current generated by the DEA allows detecting deformations impressed by the exterior and use the DEA as an active audio‐tactile interface, which produces a combined vibro‐acoustic stimulus in response to a user's touch.