A SILICON MICROVALVE WITH COMBINED ELECTROMAGNETIC ELECTROSTATIC ACTUATION/

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