Numerical modeling of the deflection of an electrostatically actuated circular membrane mirror

Abstract

This thesis outlines a numerical modeling method to describe the deflection behavior and investigate control schemes for an electrostatically actuated deformable membrane mirror, with application to focus control and aberration correction in micrelectromechanical systems. The physics of the membrane are approximated using a finite difference approach with parameters obtained from measurements of a physical device. The model is validated by comparison of simulated and measured mirror position under static and dynamic conditions. This thesis provides simulation results for control schemes that would be difficult or potentially destructive if implemented using real devices. We suggest that the model may be useful for the development of future control strategies and in refining device design. Finally, a number of capacitive sensing circuits are presented as position feedback mechanisms and the capabilities and limitations of each are examined.