عنوان مقاله [English]
Pull-in is a critical case which occurs in many micro electromechanical devices (MEMS) such as sensors, actuators and micro-electronic switches. Determination of the voltage at which Pull-in has occurred can determine the capacity of such devices. In literature, there is some work which has obtained the value of this voltage using lamped simulation or experimental analysis. In this paper, at first, the equation of voltage-displacement for transverse deflection of a circular clamped micro-plate, with a single or dual back plate, based on Von-Karman and classical plate theory, has been obtained. Then, analytical relations for static Pull-in voltage that has caused instability and damage to the system have been derived. These relations show that the value of Pull-in voltage obtained by these relations is about 1.3 times that calculated by previous researchers who used distributed mass simulation for validation of the obtained relation. Finite Element simulation for the single back plate case has been done in ANSYS software. It is shown that Finite Element Method results have good agreement with analytical results. Also, a comparison between analytical and experimental results in the literature has been undertaken and it shows that the errors are negligible. Finally, the effect of geometrical parameters, such as diameter, thickness and the gap of the diaphragm on the Pull-in voltage, in both cases, has been investigated. It is shown that the increase of thickness or gap will increase the pull-in voltage, while the increase of diameter will decrease the value of Pull-in voltage. Also, it is shown that in all cases, the value of the Pull-in voltage in the dual back plate case is more than that in the similar single back plate.