A SILICON MICROVALVE WITH COMBINED ELECTROMAGNETIC/ELECTROSTATIC ACTUATION

We report on the design, fabrication and performance of a silicon microvalve for small gas flows. It consists of two micromachined components which are bonded together. One part contains the gas flow inlet, the other part a deflectable silicon membrane. This membrane may be activated by a combination of electromagnetic and electrostatic forces. This principle is especially useful for minimizing the power consumption. The main experimental results are as follows: The. maximum pressure against which the valve can fully operate is 160 mbar. With this pressure, a flow of up to 3 ml/min can be controlled. Typically, current pulses of 200 mA and voltage amplitudes of 30 V are applied for electromagnetic and electrostatic actuation, respectively. The switching time is below 0.4 ms.