A dielectrophoresis based microdevice for separation of cancer cells from blood cells

We propose a simple dielectrophoresis-based microfluidic platform to perform continuous-flow separation of cancer cells from the blood cells. The platform comprises a microchannel and two sets of interdigitated electrodes on opposite side-walls to create non-uniform electric field. A rectangular insulator island is inserted in the middle of the separation region that directs the cells to a region of higher dielectrophoretic force closer to the electrodes without the need of a sheath flow. A diluted blood sample spiked with MDA-MB-231 cancer cells is injected in the microdevice. The frequency is tuned in such a way that the cancer cells experience a positive dielectrophoretic force and are attracted towards the electrodes while the blood cells are repelled away from the electrodes under the influence of a negative dielectrophoretic force. A Finite Element Analysis of the microdevice is performed to demonstrate successful operation of the device followed by a parametric study in which the inlet flow rate, middle island width, and the actuation voltage, are varied. The effect of each parameter on the purity of the collected sample and the efficiency of the operation is noted. Both the numerical and experimental results are presented in the present paper.