A Compact Hydraulic Head Auto-Regulating Module (CHARM) for Long-Term Constant Gravity-Driven Flow Microfluidics

Abstract

Gravity-driven flow is a simple microfluidic flow initiation and maintenance mechanism that requires no external power sources and low expertise to use. However, the driving forces created by hydraulic head differences gradually decrease during operation, resulting in unwanted decreased flow rates in many microfluidic applications. The existing methods to maintain a constant flow for gravity-driven mechanisms either require additional bulky control equipment, involve complex fabrication or operation, or introduce interfaces that lack robustness. To solve those problems, a compact hydraulic head auto-regulating module (CHARM) was designed and tested in this thesis. The module was able to maintain the liquid level at the microfluidic inlet port within a small fluctuation range without human intervention for a long operation time. The design’s compactness and its compatibility with the standard 96 well plates enable high-throughput operations, and the chosen material’s bio-compatibility allows the devices’ use on cell culture related applications.