Light‐Fueled Self‐Oscillation of a Viscoelastic Liquid Crystal Elastomer Oscillator

Abstract

Self‐oscillating systems based on active materials offer significant potential for creating autonomous intelligent machines by harnessing environmental energy and enabling self‐regulation. However, most such systems overlook the viscoelastic behavior of materials, which exhibit both elastic and viscous deformation under load, underscoring the importance of studying these effects on system performance. Herein, a viscoelastic liquid crystal elastomer (LCE) spring oscillator is presented and its dynamic behaviors are investigated. The dynamic governing equations of the oscillator are developed based on a linear thermoviscoelastic model. The analysis concludes that the system has a supercritical Hopf bifurcation between the static mode and the self‐oscillation mode. Exact expressions for amplitude and frequency, along with asymptotic equations and analytic solutions, are also provided. Additionally, key system parameters influencing the amplitude and frequency of the self‐oscillating system are examined. Especially, the viscoelasticity of LCE fiber greatly affects the bifurcation point, amplitude, and period of the oscillator. These results provide convenience and guidance for various applications, especially in related fields such as soft robotics, micromechanical systems, and energy harvesters.