Dielectrophoretic Motions of a Single Particle in the Vicinity of a Planar Wall Under a Uniform Electric Field Perpendicular to the Wall Surface

In this paper, we use a direct numerical simulation to investigate the two-dimensional dielectrophoretic (DEP) motion of a single particle in the vicinity of a planar wall under a uniform direct-current electric field imposed externally at a right angle to the wall-fluid interface. Accordingly, we solve the leaky dielectric model of Taylor and Melcher for the electric potential, and then integrate the Maxwell stress tensor to compute the DEP force. Further, we solve the continuity and Stokes equations for the flow field. For the simulations, we employ a finite volume approach, comprising a sharp interface method for the electric potential and an immersed boundary method for the flow field. The results show that the particle motion is initiated only in a direction perpendicular to the wall-fluid interface by the nearby wall, and depends strongly on the conductivity set of the particle and the wall, and their separation gap