High flow-rate piezoelectric micropump with two fixed ends polydimethylsiloxane valves and compressible spaces

Piezoelectric micropump using dual-frequency drive

“…The volume change of the pump chamber induced by the defection of the pump diaphragm can be calculated by [17] …”

“…A rectangular piezoelectric sheet attached to the metal beam actives the vibrator. In the previous design [17], the vibrator was driven in the first resonant mode B 1 (Fig. 2(a)) only and vibrated in a sinusoidal waveform.…”

“…Various micropumps have been developed in recent decade [1][2][3][4]. According to actuation principles, micropumps can be categorized into several types [1], such as electrostatic [5], piezoelectric [6,[11][12][13][14][15][16][17][18], thermopneumatic [7], electromagnetic [8], magnetohydrodynamic [9], and shape memory alloy [10]. Among these, piezoelectric micropump is the most typical one and has notable advantages of simple structure, large power density, and no magnetic influence [11][12][13].…”

“…Thus, both the working frequency and the volume change of the micropump induced by the deflection of pump diaphragm are small. Our group previously proposed a high flow rate piezoelectric micropump with a resonant-type vibrator to obtain high flow rate and high pump pressure [17]. The vibrator works at a resonant frequency of 490 Hz, and the flow rate reaches 105 ml/min at the driving voltage of 400 V p-p .…”

“…Increasing the driving voltage to increase the amplitude of the vibrator is another approach, but the voltage also have a limit. In this study, which is based on previous research [17], a dualfrequency driving method using both first and third harmonics of a square-wave voltage is proposed. The first and third bending resonant frequencies are deliberately designed to have a ratio of 1:3.…”