Miniature tubular centrifugal piezoelectric pump utilizing wobbling motion

A new kind of piezoelectric pump utilizing centrifugal force directly is introduced in this paper. It uses a metal tube to act as both the wobbling part and the liquid channel. Several piezoelectric elements attaching to the metal tube are used as the actuators to push the metal tube to wobble at its resonant frequency. The centrifugal force generated by wobbling motion will force the liquid in the metal tube out. The dynamic characteristics of the pump are studied. A prototype pump is fabricated by four piezoelectric tubes and a steel tube with an outer diameter of 1.0 mm, an inner diameter of 0.7 mm and a length of 80 mm. Experimental results show that the system can pump tap water at a flow rate of 7.7 ml/min under a backpressure of 2.0 kPa.