Normally-Closed Electrostatic Micro Valve with Pressure Balance Mechanism for Portable Fuel Cell Application

This paper describes an electrostatic micro valve which controls fuel in a portable direct methanol fuel cell (DMFC) system under development. A novel pressure balance mechanism is adopted to achieve both normally-closed operation against pressurized fuel and low voltage operation. The fabricated micro valve was tested using air as a working fluid in terms of leak pressure and driving voltage. The micro valve kept close state at input pressure from 0 kPa to 20 kPa. The driving voltage to fully open the micro valve was from 30 V to 60 V. These results well agree with the theoretical estimation.