Low voltage, high speed and small area in-plane MEMS switch

Electrostatic in-plane microelectromechanical systems (MEMS) relays/switches are widely applied for their low power consumption and simple process. However, compared to the out-of-plane designs, in-plane designs usually suffer from high pull-in voltage, since the feature size of the bulk-silicon process limits the gap between the driving electrodes. Area cost and speed usually have to be sacrificed to enhance the driving force and decrease the pull-in voltage. Balancing the pull-in voltage, speed and area cost is difficult for MEMS relays/switches but is essential in many practical applications. Comb structure is promising to relieve this contradiction. In this paper, we integrated the comb structure with the cantilever structure. As a result, the pull-in voltage decreased with the decreasing of the mass and area cost. A novel electrostatic lateral MEMS switch was introduced. The experiments have shown that 12V pull-in voltage, 120 mu s switching time with a 28V driving voltage at atmospheric pressure, and small area were fabricated using a conventional bulk-silicon process.