Progress in Filtration and Separation

3. Dielectrophoretic Treatment

3.1. Nonuniform Electric Field-Induced Effects

In uniform electric field, Coulomb forces are generated on both sides of a neutral particle. The dipole moment induced in the particle can be represented by two equal and opposite charges (δ⁺ and δ⁻) at the particle boundary, resulting in zero net force on the particle. However, when the electric field is nonuniform, the unequal fields operating on each side create a force, called dielectrophoretic force (DEP), directed along the electric field gradient, which impels the neutral body towards the region of stronger (positive DEP) or weaker electric field (negative DEP). The dielectrophoretic motion of neutral body suspended in medium is illustrated in Figure 16, in which ...