Size-dependent models of 0–1/0–3 polarized PLZT unimorphs and bimorphs based on a modified couple stress theory

Abstract

The constituent equations of both 0–1 and 0–3 polarized PbLaZrTi (PLZT) micro-cantilevers in the form of unimorphs and/or bimorphs are developed. These formulations are based on the modified couple stress theory (MCST), the laminated beam theory, and/or the Euler-Bernoulli beam theory. The thermo-electro-light-mechanical coupled fields and size effect were considered simultaneously in these equations. The present models can capture the size effect in virtue of a material length scale parameter (MLSP). The size-dependent tip deflection, equivalent bending moment and blocking force are discussed. Different materials and thicknesses of the elastic layer are considered in presented models. Furthermore, the present models can be reduced to the classical 0–1/0–3 polarized unimorph/bimorph.