A light-fueled self-oscillating liquid crystal elastomer balloon with self-shading effect

Developing new self-oscillating systems would greatly expand their applications in intelligent machines, advanced robotics, and biomedical devices, due to their advantages of directly harvesting ambient energy and self-control. In this paper, we creatively proposed a light-fueled self-oscillating liquid crystal elastomer (LCE) balloon with self-shading coating, which is capable of self-oscillating under steady ambient illumination. Based on the well-established dynamic LCE model and the ideal gas model, the governing equation of the free-standing LCE balloon is formulated, and dynamics of the self-oscillation is studied theoretically. Numerical calculations show that the balloon always evolves into two kinds of motion modes: static mode and oscillation mode. The mechanism of the self-oscillation is elucidated by the self-shading effect of the opaque power coating, and the conditions for triggering the self-oscillation are further obtained numerically. In addition, the effects of system parameters on amplitude, frequency and equilibrium position are also investigated. Amplitude and frequency are mainly affected by light intensity , damping coefficient, mass density and contraction coefficient, while are independent on initial velocity. It is anticipated that the self-oscillating balloon constructed in this paper would be of benefit in autonomous, self-sustained machines and devices with the core feature of photo-mechanical transduction.