Self-assembled robust micro check valves with large flow rates (\u3e10 cc/second, displacement related), high-pressure support ability (\u3e10 MPa) and high operational frequencies (\u3e10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single micro valves to achieve the required flow rates. A novel in situ UV-LIGA process was developed for the fabrication. Self-assembling was realized by guiding the electroforming process during the fabrication process. Test results show that the forward flow rate is about 19 cc/second under pressure of 90Psi. The backward flow rate is negligible. The reliability of the valve was tested by a specific loading/unloading sequence. Results show that the flow rates were repeated very well over a large range of tested pressure differences
