A piezoelectric micropump based on MEMS technology is presented.Polydimethylsiloxane（PDMS） is utilized to form the diaphragm

a passive valve and an active valve are formed by anisotropic etching of bulk silicon

and a piezoelectric bimorph is used as the actuator.The combination of piezoelectric bimorph and PDMS diaphragm can bring large chamber volume change

reduce the manufacture cost and increase the yields.The flow rates of the micropump are measured

and the result shows that the voltage

frequency and the back pressure all have an influence to the flow rates.When a square wave of 100 V and 25 Hz is applied

the flow rate of piezoelectric micropump reaches to 458 μL/min

and a maximum output pressure of 6 kPa is produced.