A novel approach for microparticle separation based on dielectrophoresis method

A novel approach for particles size separation based on dielectrophoresis (DEP) method is introduced and analyzed both computationally and experimentally. The proposed technique has been utilized for the separation of polystyrene (PS) particles with 8, 6 and 2 mu m diameters passing through microchannels with planar electrodes. The performance of the technique has been computationally analyzed using the finite element method (FEM). Considering the structure of the planar electrodes, we propose an approach based on applying an electric potential between one of the global electrodes, and a needle touched the top of the cell suspension. Results of both simulation and experiment show that by applying a proper voltage with 500 kHz frequency, the PS particles with 6 and 8 mu m diameters will freeze in the direction of the channel while the smaller particles can pass by and exit from the outlet of the channel. Results have shown that the DEP force exerted on the particles by the middle electrode (needle) is stronger and the separation yield is higher compared with the conventional methods.