Modeling hysteresis and step response of a carbon-nanotube-reinforced electroactive actuator

Abstract

For polymer actuators, that are useful in wide variety of applications such as microelectromechanical systems (MEMS), machine components, and artificial muscles, the nonlinear phenomena of hysteresis and creep are essential considerations. We have investigated the movement of an electroactive polymer (EAP) actuator composed of single-wall carbon nanotubes (SWNTs) and polyaniline (PANI), and have developed an integrated model that can be used for simulating and predicting the hysteresis and creep during actuation. We used the Preisach operator, one of the most popular phenomenological models of hysteresis, and the step response was depicted using the system identification technique. Understanding the behavior of the step response is especially important in open-loop control of the actuator. In this paper, we present the mathematical description of our model as well as the extraction of the parameters. Simulation results from the model and a comparison with measured data are also provided.