A compact low-power valveless piezoelectric micropump with a nested rectification structure

The field of implantable medical devices imposes stringent requirements on piezoelectric micropumps, particularly in terms of low-power operation, miniaturization, and backflow suppression. This study proposes a novel valveless piezoelectric micropump with a nested rectification structure, in which a crescent bluff body is embedded within a nozzle/diffuser to form a compact and highly efficient cascaded rectification unit. This configuration significantly enhances rectification performance and unidirectional fluid transport capability. Numerical simulations and flow rate experiments were conducted to systematically investigate the effects of the piezoelectric vibrator, the nested rectification structure, and driving parameters on the output performance of the proposed micropump. Compared with the conventional single bluff body and nozzle/diffuser, the nested structure improves rectification efficiency by 26.8% and 52.3%, respectively. The overall size of the micropump is only 10 mm × 10 mm × 3 mm. Under the low-power consumption conditions of 10-30 V and 200 Hz, the flow rate of the micropump can be adjusted in the range of 98.6-315 μL min^-1. This study provides a promising solution for low-voltage, miniaturized and high-flow delivery in medical applications and lab-on-a-chip platforms.