Dielectric charging control for electrostatic MEMS switches

This work introduces a new control method to dynamically mitigate the effects of the parasitic charge injected in dielectric layers of electrostatic MEMS switches. This method can be used to increase lifetime and reliability of electrostatically actuated MEMS devices. The method is based on the opposite behaviors exhibited by the dielectric charging phenomena when voltage stresses of different polarity are applied to a given device. To this effect, a sigma-delta sensing and actuation scheme has been implemented: device capacitance is periodically sampled and, according to the value obtained, positive or negative actuation voltages are applied. Preliminary experimental results with two different MEMS devices that demonstrate the feasibility of this method are introduced and discussed.