Authors: D. Malleo, C. Haas and M. Kraft
Affilation: University of Southampton, Microelectronics Group, United Kingdom
Pages: 700 - 703
Keywords: MEMS, micropump, piezoelectric actuation, ANSYS
We present an optimization methodology for the design of a self-priming piezoelectrically actuated pump made of a borosilicate glass bonded to silicon. New findings in the design optimization of the piezo-actuated membrane are presented: it is shown that maximum membrane deflection does not necessarily equal maximum volumetric displacement, thus it is possible to better optimize a pump for maximum flow rates than previously thought attainable. It is demonstrated how the ratio of piezo actuator to actuating membrane radius determines not only a certain maximum deflection of the membrane but also has a sizeable effect on the profile of the deflection. The use of a novel piezoelectric material, a PZN-PT crystal, is proposed here for the first time for the actuation of the pump membrane in place of the more commonly used PZT-5H. The pump can be realized with just two lithography masks, traditional wet etching techniques and solvents, and the established manufacturing technique of anodic bonding of glass to silicon. When the actuator is driven by an 85V sinusoidal signal -a voltage level which would yield acceptable Von Mises stress levels in the membrane- a flow rate performance in excess of 4000ìl/min is expected. The pump is currently being fabricated.