Resonant-based test method for MEMS devices

In this paper a test method for capacitive Micro-Electro-Mechanical Systems (MEMS) is presented. The proposed method utilizes the principle of resonant circuits to detect structural defects of capacitive MEMS devices. It is shown that a small variation of MEMS capacitance due to a defect alters the resonance frequency considerably. It is also shown that the variation of the output amplitude can be observed for fault detection if an inductor with a high quality factor is employed in the test circuit. Simulation results using an implemented MEMS comb-drive indicate that the proposed method can detect common faults such as missing, broken and short fingers.