Numerical Analysis of Coupled Particle-Fluid Transport and Free-Flow Magnetic Sorting in Microfluidic Systems

C. Liu, X. Xue, E.P. Furlani
University at Buffalo, US

Keywords: microfluidic magnetophoric sorting, magnetic bioseparation, magnetic biosorting, particle-fluid coupling, free-flow magnetophoreis

Summary:

Magnetic beads are increasingly used in microfluidic systems to selectively separate and sort biomaterial from a specimen for a broad range of biomedical and clinical diagnostic applications. Most theoretical studies of such systems have been based on one-way particle fluid coupling wherein the fluid flow influences particle motion, but the flow is assumed to be constant, independent of particle motion. Relatively few studies have taken into account two-way particle-fluid coupling wherein momentum is transferred from the particles to the fluid, thereby altering the flow. In this presentation, a computational fluid dynamics (CFD)-based method is demonstrated for predicting field-directed transport and continuous sorting of magnetic beads in microfluidic systems taking into account two-way particle fluid coupling. This method involves a hybrid numerical/closed-form modeling approach that combines numerical transport analysis with closed-form field analysis. Specifically, coupled particle-fluid transport is computed using CFD analysis, while the magnetic force that governs particle motion is obtained in closed-form. This method is demonstrated via application to various microfluidic sorting and particle assembly systems.