On-chip microfluidic separation of biological entities in field flow fractionation and split flow thin fractionation devices

Abstract

Selective separation of biological entities in microfluidic environment is an important task for a large number of bio-analytical protocols. Here we present a numerical study characterizing magnetophoretic split-flow thin (SPLITT) fractionation and compare its performance against field flow fractionation (FFF) in a microfluidic separation device. Particle trajectories in the microchannel under influence of a suitably designed magnetic field have been predicted by using an indigenous numerical code. A three-inlet and three-outlet micro-channel design configuration has been chosen for isolation of magnetic microspheres of two different sizes from a continuous flow. The configuration is chosen as a practicable option for simultaneous separation of two different biological entities from the background media. Parametric variation involving the particle size and relative widths of the outlet streams are carried out to observe the resulting influence on trajectories of magnetic beads and the particle capture and separation indices. Finally, an optimum regime of design parameter is identified that yields the maximum capture efficiency and separation index.