Dielectrophoretic Manipulation of Particles and Lymphocytes

Abstract

A particle manipulation and sorting device using the dielectrophoretic (DEP) force is described in this study. The device consists of “ladder-type”, “flip-type” and “oblique rail-type” electrode regions. The ladder-type and rail-type electrodes can generate a DEP force distribution that captures the particles, the DEP force of which is “negative” (repulsion force), in the area located at the center of the electrodes. The particles can then be guided individually along the electrode. In addition to this, the ladder-type electrode can align the particles with equal spacing in the streamwise direction. Using the “flip-type” electrode, which pushes the particles away, in combination with these electrodes, the direction of the particle can be selected with high accuracy, reliability and response. In the first half of this paper, numerical simulation was carried out to calculate the particle motion and evaluate the performance of the ladder-type electrode. Several models were validated to investigate the influences of the non-uniformity of the electric field and the electric interaction of the surface charges and polarizations. Measurement using the high-speed camera was then carried out to investigate the motions of the particles and sorting reliability. The trajectories and the probability density functions of the particles at the inlet and outlet of the electrode region showed that by using these electrodes the particles can be aligned, sorted and guided accurately.