Design and test of a high-performance piezoelectric micropump for drug delivery

With a micropump, the release rate of drug delivery is able to be controlled easily to maintain the therapeutic efficacy. A high-performance piezoelectric cantilever-valve micropump was investigated for this purpose. The effect of valves on the output performance of the PZT micropump was analyzed at first. With taking into account the influence of liquid added mass and added damping on the natural frequency of the valves and actuator, the design method of the cantilever valve was presented. Two micropumps were designed and fabricated for comparing experiments. The micropump with cantilever valves 2.5 mm in length obtained higher output values (the maximum flow rate and backpressure is 3.5 ml/min and 27 kPa, respectively) and had two optimal frequencies (0.8 and 3 kHz). While the micropump with cantilever valves 4.5 mm in length had only one optimal frequency (0.2 kHz), at which the micropump achieved lower output values (the maximum flow rate and backpressure is 3.0 ml/min and 9 kPa, respectively). The study results suggest that the output values and optimal frequency of micropump can be improved by the design of the cantilever valves.