FE modeling of stress and deflection of PZT actuated micro-mirror: Effect of crystal anisotropy

In this paper, we present finite element (FE) modeling of thermomechanical stress and deflection of lead zirconate titanate (PZT) actuated micro-mirror taking material anisotropy into account. Including silicon anisotropy in thermomechanical FE simulation resulted in 5% lower stresses and 9% higher deflections than those obtained for isotropic properties of silicon. Piezoelectric simulation with anisotropic properties of both silicon and PZT material has shown lower stresses and higher deflections compared to those obtained with isotropic properties of materials. ickness of silicon substrate in the diaphragm region has also shown to have a significant influence on the deflection of micro-mirror. The deflection was found to increase dramatically to 133 mrad with the complete removal of silicon substrate. FE modeling taking materials anisotropy into account has proved to serve as an indispensable tool to realize an optimal design of micro-mirror.