Exploiting LCE-SMP synergy for reconfigurable double layer actuators with controlled shape transformation

Microactuators face challenges in combining active deformation, shape retention, and mechanical robustness within a single material system. This work presents a bilayer actuator composed of a liquid crystal elastomer (LCE) and an epoxy shape-memory polymer (SMP), with a thickness of approximately 350 μm and an overall size at the millimeter scale. In this bilayer, the LCE layer provides thermally induced actuation, whereas the epoxy SMP layer enables temporary-shape fixation and subsequent recovery toward its permanent shape. The actuator therefore undergoes a heating-induced bending, cooling-induced fixation, and reheating-induced recovery cycle. Fabricated by blade coating, the actuator was used to investigate the effect of layer-thickness ratio on bending performance, with the tested 3:2 ratio giving the largest response among the examined specimens. After 25 thermal cycles, the actuator retained a repeatable cyclic response. A microvalve and a temperature-controlled switch were further demonstrated to illustrate potential device applications.