Enhanced fluid mixing and separation of magnetic bead agglomerates based on dipolar interaction in rotating magnetic fields

Abstract

The exposure of a highly concentrated suspension of magnetic beads in a carrier liquid to a homogeneous magnetic field results in the formation of magnetic bead superstructures due to dipolar interactions. We present a microfluidic system which employs such agglomerates to simultaneously allow for mixing and separation applications. Within the chosen structure, an increase of the diffusivity of about 32% was observed and further a separation efficiency of about 80% is achieved for flow rates up to 100 μm/s.