Origami-inspired electrohydraulic soft actuators: Multimodal robotic motion for jumping, crawling, and grasping

Abstract

Soft robotic joints demonstrate significant potential for enhancing robotic performance in complex environments through safe and powerful actuation. However, simultaneously achieving high torque, rapid response, angular displacement range, and long-term reliability in a single soft actuator remains a significant challenge. To address these challenges, we present an origami-inspired electrohydraulic soft (OES) joint that utilizes electrostatic actuation to control dielectric fluid displacement, enabling full deployment of the folded structure for precise bending motions. The OES joints demonstrate a blocking torque of 48.7 mN m and a specific torque of 19.44 N m/kg. The joints can be parametrically designed to achieve specific maximum bending angles within a wide range (0°–163°), a feature not demonstrated by other flexible joints in the literature. These advancements facilitate diverse robotic applications: (i) a jumping mechanism attaining 13.9 body-height leaps with 0.17 body lengths per second forward velocity, (ii) a crawling robot achieving 1.23 body lengths per second locomotion, (iii) a bidirectional actuator with programmable angular output, and (iv) a compliant gripper combining operational safety with high-force grasping capabilities.