Fabrication and testing of a pair of passive bivalvular microvalves composed of p + silicon diaphragms

A pair of one-way passive microvalves is fabricated by using the p + etch-stop method. The two valves have a simple structure and are easy to fabricate. Each valve consists of several p + silicon diaphragms and is designed to open and close depending on the pressure difference. The fabrication process of the valves consists of a boron diffusion and simple anisotropic etch processes. According to the experimental results, the water flow rate is 1.6 ml min^-1 at 4 kPa of forward pressure and -0.05 ml min^-1 at 4 kPa of backward pressure.