Particle Transport in Magnetophoretic Microsystems
University at Buffalo, US
Keywords: magnetic particle transport, magnetophoresis, magnetophoretic microsystem, magnetic biotransport, bioseparation, high gradient magnetic separation
Abstract:Magnetophoretic microsystems are finding increasing use in biotechnology and biomedicine for applications such as bioseparation and immuno-assays. These microfluidic systems typically contain embedded elements that produce a magnetic field distribution within a microchannel. This applied field gives rise to a magnetic force, which acts to manipulate or trap magnetic micro or nano-particles as they flow through the channel. Magnetophoretic microsystems are well suited for bioapplications because they enable fast reaction times, the analysis and monitoring of small samples, and integration with “micro total analysis systems” (uTAS). In this presentation we discuss methods and models for predicting the transport and capture of magnetic micro and nano-particles in magnetophoretic microsystems. We introduce the equations of motion, which account for the dominant magnetic and fluidic forces, as well as Brownian motion for sufficiently small particles. We describe a magnetization model for predicting the magnetic response of the particles, and use this for the magnetic force computation. We provide analytical expressions for the magnetic field and force for common magnetic structures. We apply the transport models, and compare the performance of magnetically-biased systems, with electrically actuated (current driven) systems.