title: Exploiting the wall-induced non-inertial lift in electrokinetic flow for a continuous particle separation by size.
abstract: Separating particles from a heterogeneous mixture is important and necessary in many engineering and biomedical applications. Electrokinetic flow-based continuous particle separation has thus far been realized primarily by the use of particle dielectrophoresis induced in constricted and/or curved microchannels. We develop in this work a new electrokinetic method that exploits the wall-induced non-inertial lift in a straight uniform microchannel to continuously separate particles by intrinsic properties (e.g., size and surface charge). Such an electrically originated lift force arises from the asymmetric electric field distribution around a particle nearby a planar dielectric wall. We demonstrate this method through separating both a binary and ternary mixture of dispersed polystyrene microspheres by size in a T-shaped microchannel. A semi-analytical model is also developed to simulate and understand the particle separation process. The predicted particle trajectories in the entire microchannel agree reasonably well with the experimental measurements.
authors.affiliation: Department of Mechanical Engineering, Clemson University , Clemson, South Carolina 29634-0921, United States.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Lu
authors.forename: Jyh-Ping
authors.initials: JP
authors.lastname: Hsu
authors.forename: Xiangchun
authors.initials: X
authors.lastname: Xuan
mesh_terms: D004560:Electricity; D056656:Lab-On-A-Chip Devices; D008962:Models, Theoretical; D010316:Particle Size