Large deflection analysis of circular piezoelectric micro-actuator with flexoelectric effect

Abstract

Abstract At micro/nano scale, the stiffening effect and flexoelectric effect of strain gradient play important roles in the electromechanical coupling response of piezoelectric micro-components. In this paper, the large deflection bending problem of circular piezoelectric micro-actuator is studied based on the extended linear dielectric theory. In addition to the piezoelectric effect, the coupling of strain gradient to strain gradient is included to consider the stiffening effect, the coupling of strain gradient to polarization is considered to reflect the direct flexoelectric effect, the coupling of polarization gradient to strain is used to describe the inverse flexoelectric effect, and the coupling of polarization gradient to polarization gradient is introduced to capture the high-order electric field effect. A size-dependent model of circular piezoelectric micro-actuator is established to investigate the electromechanical coupling response of piezoelectric micro-actuator based on the variational principle. The contributions of piezoelectric effect and flexoelectric effect on large deflection behaviors of piezoelectric micro-actuator are revealed. It is hoped that the research results will be helpful to further understand the electromechanical coupling properties of piezoelectric micro-components and improve the control precision of piezoelectric micro-actuator.