An Integrated Electrohydraulic Soft Robotic Fish With 3D Maneuverability and Autonomous Control

Zhen Zhang, Yingying Gao, Yiming Liang, Xinge Li, Hongcheng Qiu, Zhe Wang, Fanghao Zhou, Tiefeng Li

Abstract: Soft robots enable compliant interaction with humans and the environment. However, their widespread deployment is constrained by significant challenges, including limited mobility and the inherent complexity of incorporating power and control systems into their bodies. In this paper, we present a fully integrated electrohydraulic soft robotic fish that achieves three-dimensional maneuverability and autonomous control. To achieve effective underwater locomotion, the robot is actuated by two flapping wings, each independently controlled and powered by electrohydraulic actuators. Theoretical modeling and finite element simulation of the electrohydraulic actuator are conducted and validated through experimental results. Furthermore, the robot's electronic system integrates a range of miniaturized components—including a control board, voltage amplifiers, and sensors. This autonomous soft robot enables depth control and directional navigation. The design and control methods of this work can inspire the design of fully autonomous and intelligent soft robots for complex tasks and environments.