A Combination of Dielectrophoresis and Magnetophoresis Microfluidic Chip for Cancer Cells Separation

Nowadays, dielectrophoresis-based lab-on-a-chip devices for particle manipulation got a lot of attention because of their significant advantages including small size, low cost, power-saving, and portability. Among various particle manipulation applications, separation and analysis of circulating tumor cells (CTCs) from the blood play vital roles in the improvement of cancer diagnosis and treatment efficiency. However, the use of dielectrophoresis (DEP) in CTCs separation with high applied voltage may lead to the Joule heating effect, which results in unexpected damage to cells. In this work, a microfluidic device integrating DEP combined with magnetophoresis (MAP) and hydrodynamic focusing technique was designed to separate CTCs from blood cells and in the patient blood sample. In this device, an external electric field was induced by an electrode array that applied alternative voltages located in the channel wall. A comb-shaped permanent magnet was built to enhance the magnetophoretic effects on cells. The use of DEP assisted by MAP and flow focusing technique helped in reducing applied voltage, manipulating cells to desired outlets. The working mechanism of the proposed device was evaluated by numerical approach (finite element method). The simulation results showed that by utilizing these above methods, CTCs were successfully separated from the whole blood with superior efficiency, at 93% with an applied voltage of 2.5V. Besides, other blood cell types were separated into 3 independent outlets consisting of white blood cells (WBCs), platelets (PLTs), and red blood cells (RBCs) with their separation efficiencies respectively were 96%, 94%, and 52%. The structure provides a novel solution for circulating tumor cell isolation with great potential in biological applications such as cell analysis, cancer therapy development, drug and toxicological screening.