Dynamic analysis of a torsional mems scanner mirror, part 2: sensitivity analysis framework

Abstract

Next generation optical Micro Electro Mechanical Systems (MEMS) such as micro mirrors and micro scanners will extend the resolution and sensitivity offered by their predecessors. It is advantageous to predict the performance of such systems early in the design stage. In this study, we developed a sensitivity analysis framework to investigate the effect of the modal and physical parameters on the performance of a torsional MEMS scanner. The sensitivity framework described in this paper is related to the disturbance analysis framework which was introduced in the first part of this study. Disturbance analysis framework uses the Lyapunov Approach to obtain root-mean-square (R-MS) values of the mirror rotation angle under the effect of a disturbance torque. Analytical formulas were derived for the calculation of the modal parameter sensitivities and the results were verified by the finite difference method. The analytical formulas for the calculation of physical parameter sensitivities were described but they were found to be very inefficient due to the complexity and computational expense in calculating the eigenvalue and eigenvector derivatives included in these equations. Instead, the finite difference method was used to calculate the physical parameter sensitivities for the torsional MEMS scanner.