Novel miniature valve-based piezoelectric liquid pump

Abstract Piezoelectric pumps are an important aspect of microfluidics due to their small size, low noise, and lack of electromagnetic interference, which makes them highly 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 are fabricated, and the output performance indicators of the proposed two piezoelectric pumps are tested and compared. According to the simulation and experimental results, it appears that BPVPM is capable of discharging the fluid in the chamber at a faster rate than MPVPM; The arc-shaped channel in BPVPM, which has been found to have better energy transfer efficiency; it has been observed that the flow rate and pressure of the piezoelectric pump initially increase with the driving frequency, followed by a decrease, while they increase linearly with the voltage. Under the optimal operating conditions, the flow rate and pressure of MPVPM are 4.4 mL/min and 21 kPa, respectively, while those of BPVPM reach 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 7mm x 7mm x 1.5mm, 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.