尖角排列形式对微通道中颗粒富集的影响

Influence of Sharp Corner Arrangement on Particle Focusing in Microchannel

当引入尖角结构后,微通道中会形成强烈的流线弯曲。颗粒运动经过尖角结构时,会产生动量改变,受到动量改变引发的惯性力作用而偏离原来的运动轨迹,最终实现高效的颗粒被动式富集。本文设计并制作了双边带有对称尖角结构和不对称尖角结构的两种微通道,并对微尺度颗粒在不同尖角排列形式微通道中的富集行为进行了实验研究,发现当尖角结构分布在微通道的单边或双边对称位置时,可实现颗粒的单一位置富集,而当尖角结构分布在微通道的双边不对称位置时,无法实现颗粒的单一位置富集。本文的研究工作对于微尺度颗粒的快速富集提取着重要的意义,同时还可用于指导颗粒高效富集微通道的设计。

Sharp corners induce sufficient curved streamlines in microchannel.When particles pass by sharp corners,the momentum of particles will be changed;particles will be subjected to the momentum-change-induced inertial force,and escape from the original trajectories,achieving efficient passive particle focusing in microchannel.Following the prior research,two kinds of microchannels consisting of symmetric and asymmetric sharp corners on two sides were designed and fabricated.Then particle focusing experiments in the two kinds of designed microchannel were conducted.It is obtained when sharp corners are on one side or symmetrically arranged on two sides,single-stream particle focusing can be achieved;when sharp corners are arranged asymmetrically on two sides,particles can not be focused in one single stream.It is of great help for the fast particle focusing and extraction,and can be used for the design of particle focusing microchannel with high efficiency.