目前,微流体颗粒分离研究大多使用低黏度的去离子水作为基液,未考虑流体黏度对颗粒分离的影响.现实中广泛存在高黏度流体中的颗粒分离,如机械状态监测时需要对润滑油中的磨损颗粒进行分离.本文利用双边带有对称尖角结构的微通道,对不同黏度流体中的颗粒分离进行实验研究,发现流体黏度较低时,大颗粒受到的动量改变而引发的惯性力占优,向微通道的中心位置运动;小颗粒受到的惯性升力占优,向微通道两侧的平衡位置运动,最终实现不同尺寸颗粒的分离,分离效率约达100％.当流体黏度较高时,流体对颗粒的拖曳作用增强,显著影响颗粒在微通道中的侧向迁移行为,颗粒分离效率降低至71.5％.本文的研究工作对于微流体技术在实际中的应用有着重要的意义.“,”Most microfluidic particle separation research are based on the liquid with low viscosity,such as DI water.The influence of the liquid viscosity on the particle separation has not been taken into account.Study on the particle separation in liquid with high viscosity is highly needed,such as the debris separation in lubricant oil for machine monitoring.In this paper,microchannel with symmetric sharp corners on two sides is used to study the influence of liquid viscosity on particle separation.The result shows when the liquid viscosity is low,big particles are mainly subjected to the momentum-change-induced inertial force,migrating towards the center of the microchannel;small ones are mainly subjected to the inertial lift force,moving towards the two symmetric equilibrium positions at two sides of the channel.The particle separation efficiency is ～100％ in DI water.When the liquid viscosity becomes high,the drag effect of liquid on particles increases.As a result,the lateral migration of particles in microchannel becomes weak;particle separation efficiency reduces to ～71.5％.This research is of great help for microfluidic technologies in practical applications.