Dielectrophoretic manipulation of particles

The authors have demonstrated recently that, in general, the dielectrophoretic (DEP) force experienced by a particle has two components. The first depends upon inhomogeneities in the field strength and upon the in-phase part of the dipole moment induced in the particle by the applied electric field. This component can be identified with the conventional dielectrophoretic (cDEP) force. The second component relates to the nonuniform distribution of the phase of the field and to the out-of-phase part of the induced dipole moment. A nonuniform phase distribution corresponds to the field traveling through space. This second force component gives rise to traveling wave dielectrophoresis (twDEP). In this paper, the authors describe several electrode configurations designed to produce electric fields capable of inducing cDEP end twDEP forcer for the purpose of manipulating particles. Using DS19 Friend murine erythroleukemia cells as test particles with well characterized dielectric properties, they investigated the electrokinetic behaviors for these electrodes as a function of frequency and electrode excitation mode. Several characteristic cell electrokinetic behaviors were identified depending on the excitation characteristics of the electrodes and the cell dielectric properties including trapping linear motion, levitation and circulation of the cells. They describe these findings and rationalize them in terms of field distributions produced by the electrodes and generalized dielectrophoresis theory. The biotechnological applications of dielectrophoretic manipulation are then discussed