Fluid-Structure Interaction Analysis of a Soft Robotic Fish Using Piezoelectric Fiber Composite

Designing a high-performance soft robotic fish requires considering the interaction between the flexible robot structure and surrounding fluid. This paper introduces fluid-structure interaction (FSI) analysis used to enhance the hydrodynamic performance of soft robotic fish using piezoelectric fiber composite (PFC) as the propulsion actuator. The basic FSI analysis scheme for soft robotic fish is presented, then the numerical model of the actuator, robot structure, and surrounding fluid are described based on the FSI analysis scheme. The FSI analysis of the soft robotic fish is performed through these numerical models. To evaluate the effectiveness of FSI analysis, coupling simulation and experimental results are compared. We found that the calculated results of propulsive force and deformation displacement were similar to those for experiments. These results suggest that FSI analysis is useful and is applicable to evaluating propulsion characteristics of the soft robotic fish to improve performance.