Bioinspired Design for Soft Robot Deformation Amplification: Layout Planning, Experimental Verification, and Potential Applications

Abstract

A better capacity for moving in restricted spaces, such as pipeline inspection and post-disaster rescue, is a key point in soft locomotion robots. Therefore, the more compact design of robots attracts great attention, including the excellent deformation ratio of the robots’ structure and the integration with the actuator. However, those pose a new challenge, that is, it is difficult to coordinate the deformation ratio between the actuator and the structure. In this study, inspired by the muscle-skeleton tension structure, a novel lever-type layout of the actuator is proposed to solve this issue. Firstly, the hollow Miura-origami structure with excellent deformation ability is adopted as the skeleton of the robot. Then, theoretical and experimental results show that the deformation amplification of the actuator can be realized with the lever-type layout, i.e., the 25% deformation ratio of the SMA spring actuator can achieve about 60% deformation ratio of the Miura-origami structure. Finally, based on the equivalent dynamic model and the non-dominated sorting genetic algorithm II (NSGA-II), the operation scenario of this new layout is demonstrated through numerical simulation. The results verify the feasibility of the new design from a simulation perspective and lay the foundation for the subsequent actuation design and control of the Miura-origami earthworm-like soft robot.