Design and numerical simulation of a high-throughput dielectrophoresis microfluidic chip for continuous capture of active circulating tumor cells

Circulating tumor cells (CTCs) are critical biomarkers for cancer liquid biopsy. Efficient and non-destructive separation of CTCs places high demands on the throughput and electric field control capabilities of dielectrophoresis (DEP) microfluidic chips. However, most existing DEP technologies remain limited to processing throughputs on the order of μl/h. To enhance chip performance, a Box–Behnken response surface design is employed to optimize key structural parameters, including electrode angle, electrode spacing, and channel height. Numerical simulations are conducted to systematically evaluate the effects of these parameters on the electric field distribution, flow rate, and cell capture efficiency. The results demonstrate that, under an applied electric field below the cell electroporation threshold, the optimal chip configuration consists of an electrode angle of 90°, an electrode spacing of 240 μm, and a channel height of 100 μm, ensuring effective preservation of cell integrity and viability. Under these conditions, an alternating current voltage of 6.62 Vpp enables a capture efficiency of 98.6% for MDA-MB-231 cells at a maximum flow rate of 2.16 ml/h. This study provides theoretical support for the design of high-throughput DEP microfluidic chips for tumor cell capture in clinical applications.