Hydrodynamic filtration for on-chip particle concentration and classification utilizing microfluidics
Hydrodynamic filtration for on-chip particle concentration and classification utilizing microfluidics
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DOI：
10.1039/b509386d
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发表时间：
2005-01-01
期刊：
影响因子：
6.1
通讯作者：
Seki, M
中科院分区：
文献类型：
--
作者：
Yamada, M;Seki, M
本文提出了一种在微流控装置中实现颗粒连续浓缩和分级的新方法--流体动力过滤法。当颗粒在微通道中流动时，颗粒的中心位置不能存在于距侧壁一定距离处，该距离等于颗粒半径。所提出的方法利用了这一事实，并且使用具有多个侧分支通道的微通道来执行。通过侧通道从主流中反复抽取少量液体，颗粒被浓缩并排列在侧壁上。然后，可以通过微通道下游的其他侧通道（选择通道）根据尺寸收集浓缩和排列的颗粒。因此，将颗粒悬浮液连续引入微通道中能够同时实现颗粒浓缩和分级。在这种方法中，精密制造的微通道内的流动轮廓决定了过滤物质的尺寸限制。因此，即使当通道宽度比颗粒尺寸大得多时，也可以进行过滤，而没有通道堵塞的问题。在这项研究中，直径为1 - 3 μ m的聚合物微球的浓度增加了20 - 50倍，并根据大小独立收集。此外，成功地从血液中选择性富集白细胞。
We propose here a new method for continuous concentration and classification of particles in microfluidic devices, named hydrodynamic filtration. When a particle is flowing in a microchannel, the center position of the particle cannot be present in a certain distance from sidewalls, which is equal to the particle radius. The proposed method utilizes this fact, and is performed using a microchannel having multiple side branch channels. By withdrawing a small amount of liquid repeatedly from the main stream through the side channels, particles are concentrated and aligned onto the sidewalls. Then the concentrated and aligned particles can be collected according to size through other side channels ( selection channels) in the downstream of the microchannel. Therefore, continuous introduction of a particle suspension into the microchannel enables both particle concentration and classification at the same time. In this method, the flow profile inside a precisely fabricated microchannel determines the size limit of the filtered substances. So the filtration can be performed even when the channel widths are much larger than the particle size, without the problem of channel clogging. In this study, concentrations of polymer microspheres with diameters of 1 - 3 mu m were increased 20 - 50-fold, and they were collected independently according to size. In addition, selective enrichment of leukocytes from blood was successfully performed.