Direct Numerical Simulation of Particle Separation by Direct Current Dielectrophoresis

DC dielectrophoretic (DEP) separation of particles through a constricted microchannel was numerically investigated by a verified multiphysics finite element model, composed of the Navier-Stokes equations for the flow field and the Laplace equation for the electric field solved in an arbitrary Lagrangian-Eulerian (ALE) framework. The particle-fluid-electric field interactions are fully taken into account in the present model. The numerical predictions are in qualitative agreement with the existing experimental results obtained from the literature. The DEP particle separation depends on the particle size and zeta potential. The separation threshold of the particle size can be controlled by adjusting the applied electric field and the constriction ratio of the microfluidic channel. The proposed numerical model can be utilized for the design and optimization of a real microfluidic device for DEP particle separation.