螺旋通道中稳定增强的二次流构建及其粒子聚焦研究OA北大核心CSTPCD

Inertial microfluidics,as a microfluidic technology with the ability to precisely manipulate particles and cells with high throughput,has attracted widespread attention.However,challenges remain in achieving particle focusing with insensitivity to flow rates in large-scale channels,mainly due to the instability of secondary flows within the inertial microfluidic chip.This study developed a microstructure-assisted ultra-low aspect ratio spiral microchannel,which utilized the stability and acceleration of secondary flows to achieve inertial particle focusing.The research results demonstrated successful particle focusing within a 1 mm-wide spiral channel chip,for different diameter sizes(7.3 μm and 15.5 μm),within a wide range of flow rates(0.5-3 mL/min).The focusing efficiencies for these particles were measured to be above 94%and 99%,respectively.Additionally,it was observed that the particle focusing position was approximately 100 μm away from the channel walls,significantly larger than other inertial focusing chips.Consequently,by incorporating ordered microstructures within the spiral channel chip,the stability and enhancement of secondary flows were achieved,resulting in flow rate and particle size-insensitive inertial focusing.Compared to traditional methods of inertial focusing,this design had advantages of not requiring additional sheath flow operations,and boasted high throughput and ease of manufacturing.This innovative structure opened up vast prospects for the development of portable inertial microfluidic chips,and could be used in the fields such as cell analysis and detection,flow cytometry,and online sample processing.