A comparative study on the dielectric elastomer actuator driven Vibro-impact capsule robot

Vibro-impact capsule robots driven by dielectric elastomer actuators (DEAs) feature simple structures and high locomotion efficiencies. Stacking multiple layers of membranes on one DEA frame is a widely adopted approach to multiply the power and work output of the DEA, however, the effectiveness of utilizing a multi-layer DEA to boost the locomotion performance of DEA-driven vibro-impact capsule robots remains unclear. To this end, this paper first conducts a comprehensive numerical study on the locomotion performance of the multi-layer-DEA-driven vibro-impact capsule robots. Simulation results show the counterintuitive finding that the locomotion velocity of the robot reduces with the increasing number of layers in the DEA, and the possible factors leading to such reductions in velocity are analyzed. Next, this paper introduces a new driving scheme whereby multiple layers in The DEA are separated. Simulation results indicate that maximum velocity can be achieved by having the actuation voltages for one DEA lead the others by a relative phase between 50° to 75° as the dominant vibro-impact driving source. Improvements in the maximum velocity of the vibro-impact capsule robot by up to 70 % are achieved by using three DEAs. The key findings of the numerical studies are validated through experiments, and the consistency between the experimental and simulation results demonstrates the validity of the model.