Liquid Metal Sloshing for High‐Load Active Self‐Healing System: An Application to Tendon‐Driven Legged Robot

Abstract

Self‐healing is a promising approach for damage management in high‐load robot applications, such as legged robots. It is becoming a major function in soft robotics; however, its application to support heavyweight is relatively niche. Although previous studies has developed several self‐healing tensile modules for tendon‐driven robots, these modules suffered from deficient healing strength because of the formation of surface oxides. This study proposes a biomimetic approach to enhance self‐healing performance. This approach exploits the motion of the robot to trigger the sloshing of liquid metal, which decomposes surface oxide. The method is validated using a benchtop module test, resulting in a healed strength of over tens of kilograms. Moreover, the module enables the tendon‐driven monopod testbed to perform a squat motion 13 times after a landing impact fracture and self‐healing sequence. The self‐healing module does not break during or after the squatting motion. To the best of our knowledge, this is the first demonstration of active self‐healing behavior using a life‐sized legged robot. Thus, this study provides a novel approach in the field of self‐healing robotics for improving self‐healing, thus contributing to medical robot and mechatronic designs, including rehabilitation, surgical, and diagnostic robots.