High-throughput on-chip flow cytometry system using “microfluidic drifting” based three-dimensional (3D) hydrodynamic focusing

In this work we demonstrate the application of a three-dimensional (3D) hydrodynamic focusing technique, ldquomicrofluidic driftingrdquo in the development of a miniaturized on-chip flow cytometry system. ldquoMicrofluidic driftingrdquo utilizes viscous drag of Dean flow induced in a curved microfluidic channel to realize 3D hydrodynamic focusing in a single layer planar microfluidic device. Through force scaling analysis, numerical study, and experimental characterization, we show this technique can be successfully applied to focus large microparticles such as biological cells. A laser-induced fluorescence (LIF) detection system was incorporated with the 3D focusing device and a high-throughput (1700 cells/s) cell detection was demonstrated.