A new method of particulate separation by different dielectrophoretic holding force

In order to distinguish minor differences of particulate morphologies and dielectric properties, a new method of particulate separation by different dielectrophoretic holding force is developed in this paper. The ability for particulate captive involving electric field distribution is studied, and two kinds of negative dielectrophoretic traps are designed correspondingly. It´s found that the traps produced by narrower electrode gaps are weaker than the trap produced by wider electrode gap. It´s shown by experiments that small particles are inclined to drop into weaker traps and large particles move over to the strongest trap. The separation efficiency achieves 93% for PS beads and yeast cells.