Dynamic behavior of a new surface-micromachined piezoelectric material actuated micro-mirror device

In this paper, a finite element method is used to analyze the dynamic behavior of a piezoelectric micro-mirror taking into account both anisotropic properties of silicon chip and technologically induced stress. We propose a special arrangement of piezoelectric and substrate components to build-up the micro-mirror device. In conjunction with a special arrangement of electrodes and cuts the piezoelectric actuator layer can be used to deflect the mirror in certain directions. The numerical analysis focuses on the computation of eigenfrequencies with special attention to the influence of the anisotropic material parameters. The eigenfrequencies has been shifted to higher eigenmodes when anisotropic material parameters are considered. Technologically induced stress has resulted in substantial influence on eigenfrequencies. t-of-plane dimension (thickness) of thin-film has shown significant influence on the eigenfrequencies of micro-mirror. The fundamental eigenfrequencies increased and the flexural eigenfrequencies decreased with increasing the thickness of PZT film. Evidently, the calculated eigenfrequencies were also found to increase with increasing the thickness of silicon layer (underneath the diaphragm area).