Continuous Concentration and Separation of Microparticles Using Dielectrophoretic Force in a V-Shaped Electrode Array

Abstract

We have proposed and developed the novel principle of a V-shaped electrode array in a microfluidic pathway for continuous concentration and separation of particles by dielectrophoretic (DEP) force. The advantage of V-shape microelectrode arrays with a microfluidic flow for cell separation is that whole particles are concentrated into the center of a micropathway independent of the difference in their dielectric constants in the X–Y plane, while the particles are split between the top or bottom of the micropathway in the Z-axis direction depending on the differences in their dielectric constants and the applied AC frequency. After the application of a sinusoidal AC voltage of 1 MHz and 20 Vpp, both polystyrene spheres and Bacillus subtilis spores were concentrated at the tip of the V-shaped electrode at the center of microfluidic flow in the X–Y plane independent of their dielectric constant differences. They were also split into two directions in the Z-axis, i.e., polystyrene spheres rose to the top, and spores went down to the bottom depending on their dielectric constant differences and were successfully separated in two layered downstreams. The results indicate the potential of V-shaped electrode arrays for simple continuous purification of mixed particles depending on their dielectric constants.