A Touch-Mode Capacitance Microvalve Equipped with High Speed and Pressure Microsecond Switching Performance

In this paper, a touch-mode capacitance microvalve is described that has microsecond switching speeds for high-pressure differentials (> 10 Kpa). The microvalve has two pairs of electrodes. The first pair is an upper electrode with a membrane electrode, which acts to seal openings in the upper electrode with touch-mode capacitance. The second pair is a membrane electrode (shared with the first pair) with a lower electrode cavity, in which the membrane moves into to open the valve. The lower pair utilizes a center pad to increase the valve opening speed at a lower opening voltage. The valve includes a pneumatic assist applied to the back to decrease the net pressure across the membrane electrode, which allows the valve to operate at higher net pressure differentials. The operation of the microvalve is experimentally demonstrated with < 80 microsecond switching for a 70 kPa pressure differential.