Numerical study on a facing electrode configuration dielectrophoresis microfluidic system for efficient biological cell separation

Circulating tumor cell separation has been the focus of numerous studies owing to its importance in the diagnosis, prognosis, and therapy of cancer. This study reports a highly efficient microfluidic device that integrates a specialized dielectrophoresis configuration, namely the facing-electrode configuration dielectrophoresis (FEC-DEP) structure, to isolate circulating tumor cells (CTCs) from various blood components, including red blood cells, white blood cells, and platelets. The FEC-DEP design features a bottom-slanted electrode array positioned parallel to a basic rectangular top electrode. A non-homogeneous electric field is produced between these parallel electrodes, generating dielectrophoretic forces acting on cells. Consequently, when the FEC-DEP is integrated into a flow, it can direct various biological objects in the flow along separate trajectories. As a result, cells with comparable characteristics might move together within a similar path. This configuration may simplify the microfabrication process and lessen dependency on particle position within the microchannel. The separation process was numerically analyzed using the finite element method, and device parameters were optimized to obtain high-efficiency and high-purity cell separation. The simulations show that the microfluidic device may effectively enrich tumor cells in a label-free and non-invasive manner, with a high-efficiency rate of almost 80%.