Self-swaying of oblique bending cantilevers under steady illumination

Abstract

Self-sustained systems are able to absorb energy from steady external environment to maintain their own motion without additional energy or control. This feature has facilitated their widespread use in micromachines, actuatosr and soft robotics. To the address the relative complexity and difficulty in fabrication of the current self-sustained systems, this paper constructs a novel self-oscillating liquid crystal elastomer (LCE) fiber-beam system, which can sway continuously and periodically under steady illumination. It consists of a LCE fiber, two oblique bending cantilevers and two masses. In conjunction with the well-established LCE dynamic model and beam theory, the governing equations of the self-swaying oblique bending cantilevers system are established in this paper. The self-swaying process of the oblique bending cantilevers system under steady illumination is described and its motion mechanism is explained in detail. Numerical results show that the system can undergo supercritical Hopf bifurcation between the static regime and self-swaying regime. The effects of system parameters on the self-swaying amplitude and frequency are discussed quantitatively. The results of this paper can deepen the understanding of self-swaying and provide guidance for autonomous robots, energy harvesters, sensors and bionic instruments.