Affordable method for channel geometry–specific flow control in microfluidics without commercial pumps

Abstract

Microfluidic experiments often require precise flow control, but commercial pumps and pressure regulators are costly and can limit accessibility. We introduce a calibration-based strategy that links channel geometry with predictable relationships between pressure drop (p) and flow rate (Q), enabling stable operation of microfluidic systems using only pressurized syringes and inexpensive tubing. Silicon–glass microfluidic chips with systematically varied channel dimensions were fabricated and tested to quantify how width, depth, and length affect hydrodynamic resistance. The results revealed consistent geometry-dependent scaling of p and Q, with experimental values closely matching theoretical predictions. This calibration framework allows researchers to pre-determine safe operating conditions for syringe-driven flow, preventing chip failure and connector leakage while providing reliable flow control without specialized equipment. Beyond lowering system cost, the method highlights how chip geometry dictates achievable flow regimes, offering a design tool for laboratories where commercial pumps are unavailable.