Simulation and analysis of geometric parameters based on Taguchi method in Y-Y microfluidic device for circulating tumor cell separation by alternating current dielectrophoresis

Microfluidic technology has shown a remarkable ability to separate circulating tumor cells (CTC) in microfluidic devices. It can be used more effectively by further understanding the effect of geometric parameters on its separation performance. In this paper, the separation performance of a Y-Y microfluidic device was examined by varying its geometry parameters. In the device, the alternating current dielectrophoresis (AC DEP) method was used to separate CTC. 16 device models with various geometric parameters were created based on the Taguchi method. The geometric parameters included main channel length L, main channel width W, interelectrode angle α, and buffer inlet channel angle β. The electric field, flow field, and cell trajectory in the device were all numerically simulated to analyze the effect of geometric parameters. Signal-to-noise ratio (SNR) was used to determine the order of effect degree and optimal combination of geometric parameters. The results demonstrated that raising the flow velocity in the buffer inlet could enhance the separation purity. The separation purity was affected by the geometric parameters in the order of W> α> L> β. β had the weakest impact on the separation purity and accounted for 7.81%, while W had the most remarkable impact and accounted for 50.48%. It is found that the set of L = 1080 µm, W = 110 µm, α= 60°, and β= 60° is the optimal combination of geometric parameters. A fitting regression equation is found to describe well the effect of these parameters on separation purity. The results may provide a guide for designing microfluidic devices for separating CTC.