Curved contraction–expansion channel design to improve particle separation performance of inertial microfluidic chips

As an efficient particle separation technology, an inertial microfluidic chip has broad application prospects in biomedicine, environmental monitoring, and other fields. This paper aims to explore the influence of the curve-contraction-expansion channel structure on the particle separation performance of the inertial microfluidic chip and optimize the chip design through numerical simulation methods. The principle of the inertial microfluidic chip is introduced, and the advantages and disadvantages of the curve channel, the contraction–expansion channel, and the combination of the two are analyzed. The simulation model of the inertial microfluidic chip is established, and the influence of parameters, such as the inlet angle, channel width, channel inner diameter and overall channel curvature on the particle separation performance, is analyzed. The research results show that the curve-contraction-expansion channel structure can effectively improve the particle separation performance. The particle separation effect is best when the inlet angle is 90°, the channel width is 30 μm, the channel inner diameter is 400 μm, and the overall channel curvature is 425 μm. In addition, the article also discusses the indicators, such as particle trajectory, yield, the change of the number of outlet particles over time, and the particle focusing effect, and analyzes the influence mechanism of different parameters on the separation performance. This paper provides a theoretical basis and reference for the optimal design of inertial microfluidic chips and looks forward to its application prospects in the biomedical field.