Untethered rotational system with a stacked dielectric elastomer actuator

An untethered system can realize wide-area activities of soft robots. Herein we develop an untethered DEA wheel (UD-wheel) with a dielectric elastomer actuator (DEA). DEA is a soft actuator driven by electrostatic force. This UD-wheel is a new rotating device that integrates an untethered system and stacked DEAs. The untethered system consists of a small battery and a small high-voltage circuit. All the components are assembled seamlessly. Because the circuit can control four DEAs, the active time that the circuit continues to control the DEAs with a small battery is estimated. The estimated time matches the experimental result. We evaluated the output torque and back-drivability achieved by stacked DEAs installed in a UD-wheel. We also built a theoretical model for an in-depth evaluation. The stacking DEAs method provides a better back-drivability than the reducer method. This study suggests that our untethered rotational system may provide novel functions in soft robotics.