Light-Induced Nontethered Rolling of Liquid Crystal Elastomer and Carbon Nanotube Composite Ring

Carbon nanotubes (CNT) can enhance the mechanical and light absorption properties of the liquid crystal elastomer (LCE). Different from other ring-shaped LCE works, we proposed a ring-shaped structure using LCE-CNT composite materials that can achieve nontethered rolling with the assistance of its own gravity controlled by light. We demonstrate that the LCE-CNT composite material can lift nearly 200 times its own weight induced by light, and a cantilever beam made from it exhibits remarkable deformations to overcome gravity. Subject to light radiation, the LCE-CNT ring effectively converts light energy into mechanical energy, enabling nontethered rolling on flat surfaces, titled surfaces, and over small obstacles. Moreover, using the finite element method, we analyze the rolling mechanism of the ring induced by light and investigate the effects of light angle on the inhomogeneous deformation of the ring, the shift of the gravity center, and the generated rolling moment. The results and methods in this paper can help to give a reference for the design and analysis of intelligent soft machines.