MECH424/ENGR6371 Dr. M. Packirisamy Assignment 3 (Dues March 12th) 1. Assume you design the following platform using SOI silicon wafers. The thickness of the top layer is Sum. The initial gap between the top and bottom electrodes is 20um. a) Estimate the voltage required for the platform movement of 0.5um and 2um. b) Estimate the pull-in voltage of this system. c) Calculate the approximate natural frequency with no-voltage applied d) Calculate the natural frequencies corresponding to the static deflections of 0.5um and 2um The beam elements are assumed to be massless spring elements. The center platform is the mass clement and electrostatic field is assumed to exist only under this platform. The beams can be considered as fixed-free cantilevers with the mass attached to the tip. The beam are attached to the platform at the centers. Data: Material: Silicon, E=170GPa, poisson's ratio=0.4 20m 1000 m 500m 500m 20m (width) Static Deflection 5m