Micropump based on PZT unimorph and one-way parylene valves

This paper describes a micropump composed of a piezoelectric PZT unimorph and one-way parylene valves. Two different designs of the valves (cantilever- and bridge-type) are studied, fabricated and tested. The micropump (13 x 13 x 1.2 mm(3) in size) is capable of pumping liquid up to 700 muL min(-1) with its pumping speed being insensitive to a backpressure up to 2.5 kPa. The flow rate of 700 muL min(-1) is obtained when the micropump is driven with square pulses at 6 kHz with 50% duty cycle and 100 V peak-to-peak. The maximum static pumping pressure is measured to be 4 kPa.