Hysteresis Analysis of PLZT Actuator Based on the Photovoltaic Effect and the Viscoelastic Effect

Compared with the traditional actuators, the photostrictive actuators have huge advantages in applying in the hostile environments. The cantilever structure made of PLZT bimorph is used to increase the mechanical displacement because of the smaller photostrictive displacement of one PLZT patch. However, when one side of the PLZT bimorph was irradiated by the ultraviolet light with wavelength of 365nm, the response of the photodeformation is far slower than the photovoltage and the photocurrent, which prevents it from using in the high-frequency dynamic applications. In this study, a novel mathematical model of PLZT patch based on the photovoltaic effect and viscoelastic effect was proposed. And the tip deflection equation of PLZT bimorph was derived by the linear theory of viscoelasticity and constitutive relations of PLZT. And then the factors influencing the tip deflection were obtained by using the numerical analysis. Simultaneously, the hysteresis phenomenon of PLZT patch was explained.