Piezoelectric diffuser/nozzle micropump with double pump chambers

Abstract

To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rectification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micropump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/ Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short processing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser elements are fabricated by the anisotropic KOH-etch technique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driving force of the micropump is produced by the PZT piezoelectric actuator. The pump performance with both actuators actuated in anti-or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows steadily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.

Development of an inertia-driven resonant piezoelectric stack pump based on the flexible support structure

“…He et al developed a piezoelectric pump with three chambers connected in series for a loop cooling system, and the pump had a flow rate most up to 690.6 ml min −1 at an input sinusoidal voltage of 220 V pp and a drive frequency of 110 Hz [25]. Wang et al proposed a piezoelectric micropump with double pump chambers, which obtained the maximum backpressure of 7.8 kPa and the maximum flow rate of 1.5 ml min −1 under in-phase drive mode when driven by a 125 V pp square-wave voltage with 250 Hz excitation frequency [26]. Hu et al proposed a cascade type series-parallel hybrid three-chamber piezoelectric pump, and the experimental results showed that the optimal flow rate and backpressure in asynchronous driving mode exceeded those in synchronous driving mode by 356.54% and 123.53% respectively [27].…”