High-speed electrostatic gas microvalve switching behavior

摘要

A high-speed Ta-Si-N gas microvalve has been designed, fabricated and characterized. Ta-Si-N has a unique combination of electrical and mechanical properties suitable for robust high performance MEMS devices [1,]. The valve reported here represents the first working MEMS device integrating a sputtered Ta-Si-N layer, for use at differential pressures greater than 2 bar and capable of achieving controlled flow-rates under pulse width modulation (PWM). Previously reported,electrostatically actuated microvalves [3,4,5] were limited to operating pressures less than 200 mbar, and their switching behavior was not studied. The valve is based on a surface micormachined Ta-Si-N membrane that closes a deep reactive ion etched hole (DRIE, Fig. 1). The valve was optimized to achieve a low actuation voltage and fast commutation [6]. This study focuses on the characterization of the switching behavior of the valve membrane and its influence on the flow-rate.