An Amphibious Fully-Soft Miniature Crawling Robot Powered by Electrohydraulic Fluid Kinetic Energy

TL;DR

This paper presents a fully-soft miniature crawling robot powered by electrohydraulic fluid kinetic energy, demonstrating enhanced speed, maneuverability, waterproofing, and robustness for confined environment navigation.

Contribution

The study introduces a novel fully-soft miniature crawling robot with optimized electrohydraulic actuation, achieving high speed, multi-directional motion, and underwater capabilities.

Findings

Crawling velocity reaches 16 mm/s.

Robot weighs 6.3 g and measures 5 cm by 5 cm by 6 mm.

Achieves 3 degrees/s turning rate and 2 degrees-of-freedom translational motion.

Abstract

Miniature locomotion robots with the ability to navigate confined environments show great promise for a wide range of tasks, including search and rescue operations. Soft miniature locomotion robots, as a burgeoning field, have attracted significant research interest due to their exceptional terrain adaptability and safety features. In this paper, we introduce a fully-soft miniature crawling robot directly powered by fluid kinetic energy generated by an electrohydraulic actuator. Through optimization of the operating voltage and design parameters, the crawling velocity of the robot is dramatically enhanced, reaching 16 mm/s. The optimized robot weighs 6.3 g and measures 5 cm in length, 5 cm in width, and 6 mm in height. By combining two robots in parallel, the robot can achieve a turning rate of approximately 3 degrees/s. Additionally, by reconfiguring the distribution of electrodes in the electrohydraulic actuator, the robot can achieve 2 degrees-of-freedom translational motion, improving its maneuverability in narrow spaces. Finally, we demonstrate the use of a soft water-proof skin for underwater locomotion and actuation. In comparison with other soft miniature crawling robots, our robot with full softness can achieve relatively high crawling velocity as well as increased robustness and recovery.