A compact modularized power-supply system for stable flow generation in microfluidic devices

The miniaturization of microfluidic systems plays a pivotal role in achieving portability and compactness. However, conventional microfluidic systems heavily rely on external bulky facilities, such as syringe pumps and compressed air supplies, for continuous flow, which restricts their dissemination across various applications. To address this limitation, micropumps have emerged as a potential solution for portable power supply in microfluidic systems, with piezoelectric micropumps being widely adopted. Nonetheless, the inherent pulsatile mechanism of piezoelectric micropumps leads to unstable flow, necessitating appropriate mitigation for applications requiring flow stability. This research introduces an innovative hybrid pumping system that integrates a wirelessly controlled micropump with a 3D-printed modular microfluidic low-pass-filter. The primary objective of this system is to offer a portable and stable flow source for microfluidic applications. The system design and characterization are based on a three-element circuit model. Experimental results demonstrate a highly stabilized flow rate of 657 ± 7 µL/min. Furthermore, the versatility of the system is showcased by successfully forming droplets with a polydispersity ranging from 1.5% to 4%, comparable to that of bulky commercial pumping systems. This hybrid pumping system offers a promising solution for applications necessitating portable and stable flow sources, and its reconfigurability suggests potential integration into multifunctional microfluidic platforms.