Light-powered self-sustained chaotic motion of a liquid crystal elastomer-based pendulum

Self-sustained chaotic system based on active materials, where energy is absorbed directly from the environment to maintain one's own motion, furnishes an extensive scope of applications in energy harvesters, encrypted communication, bionic heart devices and other fields. This paper seeks to put forward a self-sustained chaotic pendulum system consisting of a liquid crystal elastomer fiber and a mass sphere under steady illumination. To investigate the self-sustained chaotic behavior of the pendulum system, we combine the dynamic liquid crystal elastomer model with principles of dynamics to establish the corresponding theoretical model of the system. Numerical results suggest that three typical motion modes, namely, static mode, self-sustained oscillation mode and self-sustained chaotic motion mode, are involved in the liquid crystal elastomer pendulum. The selfsustained motion is maintained by the work done by the contraction of the liquid crystal elastomer fiber with a light-blocking coating, which compensates for the energy dissipated by the damping. Furthermore, this study also explores the influences of five system parameters on the motion behavior of the LCE pendulum, and determines the key parameter values for the three distinct motion modes through detailed calculations and bifurcation diagrams. The present research findings demonstrate that introducing a new degree of freedom into the self-sustained periodic vibration system, it is possible to achieve self-sustained chaotic motion, providing significant insights into the development of self-sustained chaotic systems derived from active materials.