State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China.
Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325-3903, USA.
Biomicrofluidics. 2014 Apr 2;8(2):024108. doi: 10.1063/1.4870253. eCollection 2014 Mar.
A new microchannel with a series of symmetric sharp corner structures is reported for passive size-dependent particle separation. Micro particles of different sizes can be completely separated based on the combination of the inertial lift force and the centrifugal force induced by the sharp corner structures in the microchannel. At appropriate flow rate and Reynolds number, the centrifugal force effect on large particles, induced by the sharp corner structures, is stronger than that on small particles; hence after passing a series of symmetric sharp corner structures, large particles are focused to the center of the microchannel, while small particles are focused at two particle streams near the two side walls of the microchannel. Particles of different sizes can then be completely separated. Particle separation with this device was demonstrated using 7.32 μm and 15.5 μm micro particles. Experiments show that in comparison with the prior multi-orifice flow fractionation microchannel and multistage-multiorifice flow fractionation microchannel, this device can completely separate two-size particles with narrower particle stream band and larger separation distance between particle streams. In addition, it requires no sheath flow and complex multi-stage separation structures, avoiding the dilution of analyte sample and complex operations. The device has potentials to be used for continuous, complete particle separation in a variety of lab-on-a-chip and biomedical applications.
一种新型微通道，具有一系列对称的尖角结构，用于被动的尺寸相关的粒子分离。不同尺寸的微粒子可以基于微通道中尖角结构产生的惯性升力和离心力的组合完全分离。在适当的流速和雷诺数下，由尖角结构引起的离心力对大颗粒的影响强于小颗粒；因此，在经过一系列对称的尖角结构后，大颗粒被聚焦到微通道的中心，而小颗粒则聚焦在微通道两侧壁附近的两个颗粒流中。不同尺寸的颗粒可以完全分离。使用 7.32 μm 和 15.5 μm 的微粒子验证了该器件的颗粒分离。实验表明，与之前的多微孔流分馏微通道和多级多微孔流分馏微通道相比，该装置可以完全分离两种尺寸的颗粒，颗粒流带更窄，颗粒流之间的分离距离更大。此外，它不需要鞘流和复杂的多级分离结构，避免了分析物样品的稀释和复杂的操作。该装置有望在各种微流控芯片和生物医学应用中用于连续、完全的颗粒分离。
