A novel micro valve made of photosensitive polyimide (PSPI) was designed, fabricated and demonstrated. The dimension of chip of microvalve is less than 5 × 4 × 0.5mm3. It is designed for flow rate of about 20ml/min at a system pressure level of about 1 bar. The open pressure in positive direction is less than 250Pa while the leakage of reverse direction is almost zero. The strength of the valve is enough to withstand the reverse pressure level of more than 5 bar. The micro valve was used in a micropump as the flow direction control element. Almost all of its fabrication processes are compatible with IC processes.
At the meanwhile, the design and fabrication of polysilicon microvalve and single crystallite silicon microvalve are discussed in the same paper as contrast.