Electrothermally-induced controllable self-actuated oscillation in liquid crystal elastomer mechanical metamaterials under steady-state circuits

Self-actuated oscillation systems possess the unique ability to extract energy from their surroundings to sustain oscillation autonomously, which makes them ideal for applications in soft robotics, active actuators and smart devices. In contrast to conventional materials, mechanical metamaterials, known for their negative Poisson's ratio and volume expansion properties, can boost the functionality and performance of self-actuated systems. This theoretical study proposes an electrothermally-induced self-actuated oscillation system in liquid crystal elasomter (LCE) mechanical metamaterials under steady-state circuits and investigates its self-actuated mechanism and behavior. The electrothermal effect caused by the external electrical circuit enables LCE fibers to do net positive work. When the net positive work done by LCE fibers exactly compensates for the damping dissipation of the system, self-actuated oscillation can be triggered and maintained. The results indicate that self-actuated oscillation can be modulated and controlled by system parameters. The procedure can pave the path for designing active micromachine, energy harvester, medical devices and monitoring sensors.