Fabrication and characterization of traveling wave dielectrophoretic (twDEP) microfluidic devices

In this work, we present a microfluidic device with 16 parallel electrodes array and microchamber for cell manipulation by traveling wave dielectrophoretic force. Polystyrene microspheres suspensions in water were used as the tested cells. Cells respond to the electric field in various mechanisms depending on the frequency of applied AC signals. When the frequency of applied AC fields is in the range where dielectrophoresis (DEP) is negative, cells experience twDEP force in such a way that they were repelled from the electrode rather than being trapped by positive DEP. As the frequency of the applied signals is in the range of 50 -700 kHz, cells were move under the influent of twDEP force. As the frequency of the applied signals is more than 700 kHz, cells started moving out of the center between electrodes. These results are consistent with the theory. Because of the fact that twDEP force depends on the effective polarizability and size of particle, it gives us a chance to make the device for cells fraction and separation which can be further applied in biological and medical application such as motion control and cell selectivity.