Inchworm-Like Soft Robot with Multimodal Locomotion Using an Acrylic Stick-Constrained Dielectric Elastomer Actuator

Abstract

Inchworm-like robots have been increasingly investigated in recent years. However, most studies have focused on one or several locomotion modes, lacking in terms of inverted climbing, movement with a heavy load, and climbing a vertical plane. Herein, an inchworm-like soft robot is actuated with multimodal locomotion using an acrylic stick-constrained dielectric elastomer actuator (ASCDEA). By assembling the ASCDEA with a flexible support frame, a soft saddle-like shape body is designed to provide the shape deformation ability for the robot. This design enables the robot to move under a heavy load. Two electroadhesion actuators are designed to implement the anchoring action. Additionally, a coordination control strategy is developed to synchronize the shape deformation and electroadhesion for multimodal locomotion. Experimental results confirm that the designed robot can move at a maximum velocity of 39.55 mm s−1 (0.53 body length s−1) on an inverted plane. Moreover, the robot is capable of multimodal locomotion, including inverted climbing, vertical climbing, horizontal crawling, turning locomotion, and rapid movement with a heavy load. The developed soft robot can navigate through a confined horizontal tunnel while carrying a payload, cross a gap, circumvent obstacles, and is particularly robust owing to its compliance.