Novel miniature valve-based piezoelectric liquid pump

Abstract

Piezoelectric pumps play a crucial role in microfluidics owing to their compact size, minimal noise, and absence of electromagnetic interference, rendering them exceptionally versatile. As technology advances, the field of microfluidics requires higher standards for miniaturization, flow rate, and pressure of piezoelectric pumps. This paper introduces two novel miniature valve-based piezoelectric liquid pump with distinct structures: the Mono-port valved piezoelectric micropump (MPVPM) and the Bi-port valved piezoelectric micropump (BPVPM). The primary distinguishing factor between the two is the number of cantilever beam valves at the outlet, with the former featuring one set and the latter featuring two sets. Firstly, simulation software is employed to analyze the inlet/outlet valves, the surrounding flow field, microchannels, and the overall operation process. Secondly, the key structural parameters of the piezoelectric pump are optimized through experiments. Finally, prototypes of both piezoelectric pumps are fabricated, and their output performance indicators are tested and compared. According to simulation and experimental results, the BPVPM demonstrates a faster discharge rate of fluid from the chamber compared to the MPVPM. The arc-shaped channel in the BPVPM exhibits superior energy transfer efficiency. It has been observed that both the flow rate and pressure of the piezoelectric pump initially increase with driving frequency, followed by a decrease, while they increase linearly with voltage. Under optimal operating conditions, the MPVPM achieves a flow rate of 4.4 mL/min and a pressure of 21 kPa, whereas the BPVPM achieves 5.1 mL/min and 25.7 kPa. This suggests that BPVPM has a superior output performance compared to MPVPM. Additionally, both proposed piezoelectric pumps have the same dimensions of 7 mm x 7 mm x 1.5 mm, making them compact and efficient. This piezoelectric pump exhibits good comprehensive output performance in a small size and holds potential practical value in fields such as biomedical, cooling systems, fuel supply, and chemical engineering.