Light-powered self-scrolling liquid crystal elastomer crane.

Traditional liquid crystal elastomer (LCE)-based machines are constrained by the need for complex controllers and large power supplies, which limits their applicability in microrobots and other small-scale machines. In this paper, we propose a light-powered self-scrolling LCE crane, which is capable of self-scrolling to lift weights under steady light. Based on a dynamic LCE model, we derive the lateral curvature of the LCE crane and the driving moment for steady scrolling. By numerically solving the equilibrium equations, we found that the driving moment for the self-scrolling is originated from the uneven distribution of the LCE rod in the horizontal direction caused by light. The angular velocity of the self-scrolling depends on five system parameters: heat flux, coefficient of heat transfer, support spacing, weight mass, and scrolling friction coefficient. Through experimental comparative analysis, the results are consistent with the numerical simulation. The light-powered self-scrolling LCE crane device proposed in this paper features a simple structure, consistent horizontal illumination, and a compact light irradiation area. It advances the understanding of self-sustaining structures utilizing active materials and offers valuable insight into the potential applications of light-responsive LCEs in self-driven devices, medical instruments, robotics, sensors, and the energy sector.