Continuous Separation of Microparticles in an Inertial-Based Dielectrophoretic Device

In this study, polystyrene particles with different diameters suspended in deionized water are continuously separated in a novel spiral microfluidic chip using the dielectrophoretic force. The proposed device consists of two curved and straight microchannels. Deionized water and three polystyrene particles with diameters of 10, 15, and 17 μm enter the microchannel. In the curved part, the larger particles are separated from the 10-μm particles due to inertial force. An array of three planar microelectrodes is located on the bottom wall of the straight section. By applying an alternating current to the microelectrodes, a non-uniform electric field is created to separate larger particles (15- and 17-μm ones). Various simulations are performed at Reynolds numbers (Re) from 50 to 150. For Re = 100, 15- and 17-μm particles are completely separated from 10-μm particles. The results demonstrate that at a voltage of 80-100 V, 17-μm particles are separated from 15-μm particles due to negative dielectrophoresis. In addition, increasing the electrical voltage enhances the distance of the 17-μm particle flow from the 15-μm particle flow.