Dynamic Flexoelectric Actuation and Vibration Control of Beams

Abstract

A flexoelectric cantilever beam actuated by the converse flexoelectric effect is evaluated and its analytical and experimental data are compared in this study. A line-electrode on the top beam surface and a bottom surface electrode are used to generate an electric field gradient in the beam, so that internal stresses can be induced and applied to distributed actuations. The dynamic control effectiveness of the beam is investigated with a mathematical model and is validated by laboratory experiments. Analyses show that the actuation stress induced by the converse flexoelectric effect is in the longitudinal direction and results in a bending control moment to the flexoelectric beam since the stress in the thickness is inhomogeneous. It is found that thinner line-electrode radius and thinner flexoelectric beam lead to larger control effects on the beam. The position of the line-electrode on the top surface of the beam also influences the control effect. When the line-electrode is close to the fixed end, it induces a larger tip displacement than that is close to the free end. Analytical results agree well with laboratory experimental data. This study of flexoelectric actuation and control provides a fundamental understanding of flexoelectric actuation mechanisms.