School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
Electrophoresis. 2020 Jun;41(10-11):973-982. doi: 10.1002/elps.201900397. Epub 2020 Jan 13.
A novel method is reported to enhance the focusing of microparticle in the viscoelastic fluid. Gradually contracted geometry is designed in microchannel, which changes the distribution of the elastic lift force on the cross section. Additionally, it induces the viscous drag force and the Saffman lift force in the lateral direction. Under the combined effect of these forces, microparticles fast migrate to the center of the channel. In comparison to the channel with constant cross section, the present channel significantly enhances the particle's lateral migration, leading to efficient viscoelastic particle focusing in a short channel length. The influence of flow rate, channel length, particle size and fluid property on the particle focusing is also investigated. With simple structure, small footprint and perfect particle focusing performance, the present device has great potential in the particle focusing processes in various lab-on-a-chip applications.
一种新方法被报道可以增强粘性流中微粒子的聚焦。在微通道中设计逐渐收缩的几何形状，改变了横截面上弹性升力的分布。此外，它还会在侧向产生粘性曳力和萨夫曼升力。在这些力的共同作用下，微粒子快速迁移到通道中心。与具有恒定横截面的通道相比，本通道显著增强了粒子的侧向迁移，从而在短通道长度内实现了有效的粘性弹性粒子聚焦。还研究了流速、通道长度、粒子大小和流体性质对粒子聚焦的影响。本装置结构简单、占地面积小、粒子聚焦性能良好，在各种微流控芯片应用中的粒子聚焦过程中具有很大的潜力。
