Microfluidic continuous particle/cell separation via electroosmotic-flow-tuned hydrodynamic spreading
Microfluidic continuous particle/cell separation via electroosmotic-flow-tuned hydrodynamic spreading
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DOI：
10.1088/0960-1317/17/10/010
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发表时间：
2007-10-01
影响因子：
2.3
通讯作者：
Hjort, Klas
中科院分区：
文献类型：
--
作者：
Wu, Zhigang;Liu, Ai Qun;Hjort, Klas
在微流控分离方法中，流体动力学铺展是一种基于尺寸差异的简单且高通量的连续分离技术。然而，在微流体装置中精确地调节微小的压力差是困难的。在这项研究中，一个组合的电渗流和流体动力学流扩展被用来调整颗粒的尺寸分离。在微通道中，在机械外压和电渗透压的共同作用下，不同种类的颗粒悬浮液流与无颗粒载体流被共同驱动。通过电等效模型和数值模拟，实验研究了EOF调谐的水动力扩散行为。当机械感应压力和电感应压力的大小相似时，压力驱动流的可调谐性变得显著。因此，可以通过调谐电源容易地调节流体动力学扩展。用1.9和9.9 μ m荧光聚苯乙烯颗粒更详细地研究了分离。此外，分离E.大肠杆菌和酵母细胞。总之，该技术具有良好的机械压力驱动流动的稳定性和精确的调节的流量的优点，并提供了一个强大的方法，基于尺寸的颗粒和细胞的分离。
Among the microfluidic separation methods, hydrodynamic spreading is a simple and high-throughput continuous separation technique based on the difference in size. However, it is difficult to adjust tiny pressure differences accurately in microfluidic devices. In this study, a combination of electroosmotic flow (EOF) and hydrodynamic flow spreading was employed to tune the size separation of particles. A stream with different kinds of particle suspensions was driven co-fluently with a particle-free carrier stream under both mechanical external and electroosmotic pressure in a microchannel. The EOF-tuned hydrodynamic spreading behaviour was investigated experimentally and modelled through an electric equivalent model and numerical simulation. When the magnitudes of the mechanically and electroosmotically induced pressures were similar, the EOF tuning on the pressure-driven flow became significant. Hence, the hydrodynamic spreading could be easily adjusted by a tuned power supply. The separation was studied in more detail with 1.9 and 9.9 mu m fluorescent polystyrene particles. Moreover, separation of E. coli and yeast cells was accomplished. In conclusion, this technique has the advantages of good stability of mechanical-pressure-driven flow and precise tuning of the EOF, and provides a robust method for size-based separation of particles and cells.