Design of a piezoelectric-hydraulic pump with active valves

The design of a piezoelectric-hydraulic pump with innovative active valves is presented in this study. The pump structure consists of a piezoelectric stack actuator and two piezoelectric unimorph disc valves acting as inlet and delivery valves. The pump actuation mechanism is composed of a pumping chamber and a diaphragm attached to the piezoelectric stack actuator. Static and dynamic piezoelectric finite element analyses have been used to maximize the delivered fluid volume per stroke and to predict the dynamic behavior, respectively. A structural optimization technique has been employed to optimize the pump's efficiency for specific geometrical dimensions. A transient computational fluid dynamics (CFD) model has been utilized to predict flow rates. Dynamic experiments have also been conducted and results are in good agreement with those obtained from simulations.