Self-oscillation chaotic motion of a liquid crystal elastomer pendulum under gradient-stabilized illumination

Self-oscillation chaotic motion systems utilizing active materials hold promise for applications in diverse fields such as biomimetic mechanics and medical devices. However, there is currently insufficient exploration of chaotic motion systems. This paper proposes a novel self-oscillation chaotic motion system composed of a liquid crystal elastomer fiber and a mass ball under gradient-stabilized illumination. To explore the self-oscillation motion characteristics of liquid crystal elastomer pendulum system, a theoretical construct is formed by merging the dynamic liquid crystal elastomer model with the dynamic principle. The numerical results demonstrates that the liquid crystal elastomer pendulum exhibits three typical self-oscillation motion modes, which are in-situ oscillation mode, self-oscillation periodic mode, as well as self-oscillation chaotic mode. Moreover, analyzing the balance between liquid crystal elastomer fiber tension work and damping dissipation elucidates the mechanism of periodic mode and chaotic mode. Further, this study investigates the effect of five vital parameters on the self-oscillation motion. The bifurcation diagram effectively illustrates the transformation of oscillation modes and bifurcating routes with the system parameters. It is worth mentioning that existing study has shown that the pendulum can only oscillate periodically under annular gradient illumination, while the radial gradient illumination in this paper can induce chaotic oscillation. The research findings enhance our comprehension of motion behaviors based on active materials, and have significant implications for areas such as nonlinear oscillators and communication encryption.