Design and investigation of a resonant piezoelectric pump with high output pressure using a displacement-amplifying vibrator

Abstract

Abstract A resonant piezoelectric pump using a displacement-amplifying vibrator is proposed in this paper to improve the output pressure of the piezoelectric pump. The piezoelectric pump is composed of a displacement-amplifying vibrator and a pump body. The displacement-amplifying vibrator consists of two amplifiers and two piezoelectric stacks. The pump body comprises a piston shaft, an orifice plate, a valve body, check valves and a runner plate. A clearance exists between the piston shaft and the orifice plate. A groove is designed on the piston shaft, and the pump body is sealed by O-rings. The displacement-amplifying vibrator works in the resonant state, which has a large output amplitude. In this paper, the working principle of the piezoelectric pump is introduced and the influencing factors of output pressure of the piezoelectric pump are theoretically analyzed. The resonant frequency and stiffness of check valves with different thicknesses are simulated and compared, and three displacement amplifiers are designed and simulated. Prototypes of piezoelectric pump are made, and the effect of valve thickness, the diameter of piston shaft, and the displacement-amplifying vibrator is experimentally investigated. The experimental results show that the piezoelectric pump prototype with displacement-amplifying vibrator 3, 10 mm piston shaft and 0.05 mm-thick check valve has the maximum output pressure. Under the driving voltage of 500 Vpp, the maximum output pressure is 4.73 MPa, and the maximum flowrate is 65.7 ml min−1.