Soft Crawling and Flipping Robots Based on Liquid Metal-Liquid Crystal Elastomer Composites

Soft robots have shown great advantages with simple structure, high degree of freedom, continuous deformation, and benign human-machine interaction. In the past decades, a variety of soft robots, including crawling, jumping, swimming, and climbing robots, have been developed inspired by living creatures. However, most of the reported bionic soft robots have only a single mode of motion, which limits their practical application. Herein, we report a fully 3D printed crawling and flipping soft robot using liquid metal incorporated liquid crystal elastomer (LM-LCE) composite as the actuator. With the application of voltage, liquid metal works as the conductive Joule heating material to induce the contraction of the LCE layer. The bending angle of the LM-LCE composite actuator highly depends on the applied voltage. We further demonstrate that the soft robot can exhibit distinct moving behaviors, such as crawling or flipping, by applying different voltages. The fully 3D printed LM-LCE composite structure provides a strategy for the fast construction of soft robots with diverse motion modes.