Dielectrophoresis Field-Flow Fractionation for Continuous-Flow Separation of Particles and Cells in Microfluidic Devices

Abstract

The ability of separating particles and cells in continuous flow is always desirable as it allows faster biomedical diagnosis. This chapter presents a review on the development of dielectrophoresis field-flow fractionation (DEP-FFF) technologies for continuous-flow separation of particles and cells in microfluidic devices. The review is mainly focused on the publications between 2005 and 2012. During separation processes, DEP-FFF transports particles and cells with hydro- dynamic liquid flow in microchannels and fractionates particles and cells using dielectrophoresis (DEP) force generated perpendicular to the fluid flow direction. In the literature, numerous strategies have been developed to advance the way of generating nonuniform electric field which is required to produce DEP force, and four main strategies are grouped here, including (1) the use of planar electrodes, (2) the use of three-dimensional and sidewall electrodes, (3) the use of insulating topographical structures, and (4) the use of combined planar electrodes and insulating structures. DEP-FFF microfluidic devices can serve as a label-free, non-invasive and most efficient tool for manipulating and separating various biosamples such as particles, cells and DNA based on their polarizabilities in nonuniform electric field.