Variable-flow microvalve structure fabricated with silicon fusion bonding

The combination of silicon fusion bonding fabrication technology and detailed finite-element modeling is used to provide a framework for implementing a new concept in silicon microvalves. The device described is specifically designed for potential use in a current-to-pressure converter. The pressure inside the expansion chamber is controlled by adjusting the flow rate in a leakage path between the orifice and the chamber. Flow rate is regulated by a small valve, typically electromagnetically or piezoelectrically actuated, at flow rates of about 20 cm/sup 3//s. When the valve is fully open, the pressure in the chamber is minimized (3 psi); when the valve is closed, the pressure in the chamber is maximized (15 psi). Optimization of design features using finite-element analysis increased the deflection capability of the valve flapper by at least a factor of 5, over +or-75 mu m.<
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