Development of DEA Underwater Robot Mimicking Fish White Muscle Structure

Soft underwater robots have been actively studied because soft robots are useful for mimicking the flexible swimming shape of fish. However, typical soft actuators have low generated force and small displacement, which may lead to poor performance of robots. In this paper, we developed an oblique cone dielectric elastomer actuator (DEA) module inspired by the structure of the white muscles of fish, which are used when a instantaneous force is required (e.g., rapid starting and turning). The oblique cone DEA module recorded a maximum bending angle of 7.4 deg when 10 kV was applied. The maximum generated force was 2.06 N. The results for both bending angle and generated force were better for the oblique cone than for the cone due to the effect of mimicking the shape of the white muscle. Finally, we successfully conducted swimming experiments using a prototype of fish robot constructed by connecting multiple oblique cone modules.