Self-synchronization of a two-span liquid crystal elastomer continuous beam above a hot platform

Thermally-driven self-oscillating systems offer significant potential for ambient energy harvesting and smart actuation by converting thermal energy directly into mechanical motion. However, existing self-oscillating systems are fundamentally constrained by their single-degree-of-freedom operation, which limits functionality and prevents cooperative motion across structural segments. Drawing inspiration from the highly efficient “reverse flap-reset” wing motion in flying insects, we developed an innovative synchronized sustainable system using a thermally responsive two-span continuous beam with fixed ends and central hinge, powered by liquid crystal elastomer actuation. By combining liquid crystal elastomer dynamic modeling with structural displacement analysis, we establish a complete theoretical framework that explains the system's self-synchronization behavior. Both numerical simulations and experimental results consistently reveal two distinct operational modes: static equilibrium and self-synchronization. Our parametric analysis further demonstrates how self-synchronization is controlled by key factors including thermal excitation threshold and damping ratio. The proposed bioinspired self-synchronization represents a significant advance over conventional single-mode self-oscillating systems, achieving multidimensional motion output through an ingeniously simple architecture. This work not only provides fundamental insights into synchronized thermal actuation but also enables practical applications in bioinspired robotics and self-powered microsystems where energy-efficient, compact designs are essential.