Light-Propelled Self-Swing of a Liquid Crystal Elastomer Balloon Swing

Abstract

Light-propelled self-oscillation based on liquid crystal elastomers (LCEs) has been widely harnessed in designing soft robotics and actuating automatic machine fields due to no additional human control, precise manipulation and fast response. In this study, the light-propelled self-swing manner of an LCE balloon swing upon constant illumination is originally constructed and the corresponding nonlinear dynamic model is built. The solution strategy for evolving equation with respect to the swing angle is presented in light of Runge–Kutta explicit iterative approach. Two representative motion manners, i.e., static manner and self-swing manner, are presented. Self-swing mechanism is elucidated where the contraction and relaxation of the LCE balloon is coupled with the back-and-forth swing process and constant light energy from the environment is absorbed by the LCE balloon to compensate for the damping dissipation of the system. The impact of system parameters on self-swing is elaborated. The obtained results evince that self-swing motion can be triggered and tuned by virtue of some system parameters involved. Meanwhile, the frequency and amplitude of self-swing can be tailored to practical needs. Further, the results also furnish new insights into understanding of self-swing phenomenon and present new designs for future self-actuated soft micro-robotics system.