MIN HU
Nanyang technological University, School of Mechanical ns Production Engineering, 50 Nanyang Ave, Singapore 639798, Singapore
HEJUN DU
Nanyang technological University, School of Mechanical ns Production Engineering, 50 Nanyang Ave, Singapore 639798, Singapore
SHIH-FU LING
Nanyang technological University, School of Mechanical ns Production Engineering, 50 Nanyang Ave, Singapore 639798, Singapore
BO LIU
Data Storage Institute, 5 Engineering Drive 1, Siangpore 117608, Singapore

This paper presents a bulk micromachined check valve with very high frequency and extremely low leak rates. The valve is designed to have a hexagonal orifice, a hexagonal membrane flap and three flexible tethers. The three elbow-shaped flexible tethers are used both to secure the membrane flap to the valve seat and to abtain a large flap displacement in the forward flow direction. SOI wafer and DRIE technology are used to implement this micro valve. A very simple farbication process has been developed, and only two photolithographic masks are employed. Preliminary testing on a 1.5 milimeters size check valve shows that a maximum flow rate (DI water) of 35.6ml/min was obtained at pressure drop of 65.5kPa and negligible leakage rate in the reverse flow direction observed at pressure up to 600kPa.

Micro Check Valve; Micro Fluidic System; SOI Wafer; DIRE