Performance of a bionic Carangidae robot fish based on a dielectric elastomer material.

Carangidae fish feature streamlined, oval, or rhomboid bodies with flat and high sides, making them adept at swimming swiftly through water with minimal resistance. Dielectric elastomers (DEs), known for their high strain, rapid response times, and high electromechanical coupling efficiency under an electric field, are intelligent materials suitable for creating various actuators widely employed in flexible bionic robots. By utilizing smart material-driven soft fins, bionic robot fish can more realistically simulate the movements of actual fish, improving their swimming performance. In this study, we employed a DE-based actuator to develop a bionic robot fish resembling Carangidae, driven by fins. Leveraging the minimum energy structure of DE material, we designed a structure inspired by the Carangidae family to replicate the fin swing of the bionic robot fish. We investigated the swimming behavior of this bionic robot fish under sinusoidal voltage signals of varying amplitudes and frequencies. The bionic robot fish swims in the medium and/or paired fin (MPF) propulsion mode, achieving a maximum speed of 8.6 mm/s. This work presents a novel scheme and theoretical foundation for the application of dielectric elastomers in bionic Carangidae robots.