A physics based model for twisted and coiled actuator

This paper presents the static and dynamic modeling for a recently discovered artificial muscle-twisted and coiled actuator (TCA). This actuator can generate large force and displacement; moreover, it is low-cost, easy to fabricate, and customizable. Since the discovery of TCA, it has been widely adopted for various robotic applications. Nevertheless, theoretical models to describe the static performance and dynamic response are underexplored. In this paper, we aim to model the statics and dynamics for TCA from physics perspective. Specifically, the developed model utilizes parameters related to the working principle and material properties of the actuator. Experiments are conducted to verify the proposed model, and the results demonstrate that the proposed model can predict the static performance and dynamic response for the actuator. Given the wide applications of TCA in robotics, the developed model will enable closed-loop control of robotic systems with TCAs to achieve precise motion.