Pressure barrier of capillary stop valves in micro sample separators
Pressure barrier of capillary stop valves in micro sample separators
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DOI：
10.1016/j.sna.2004.02.036
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发表时间：
2004-09-21
影响因子：
4.6
通讯作者：
Chang, PY
中科院分区：
文献类型：
--
作者：
Leu, TS;Chang, PY
本文提出了一种基于有源CD类微流控平台的微量样品分离器内毛细管截止阀压力屏障的简单而准确的表征方法。采用热压工艺在聚碳酸酯(PC)衬底上制作了毛细管截止阀和微量样品分离器。当通道几何形状突然改变时，毛细管阀使用毛细压力屏障阻止液体在微流控装置内流动。实验是在平台上旋转微型样品分离器进行的。停在微量样品分离器内的液体样品有望通过密度梯度离心法进行分离。分析所需的各种密度段的样品可以通过简单地以不同的速度旋转来分离。对微量样品分离器中毛细管阀的设计参数进行了理论分析。结果表明，修正后的三维弯月面模型能较好地预测毛细管阀设计中的压阻。对阀门特性进行了详细的理论分析，并与实验测量结果进行了比较。然后提取了阀的模型，该模型表征了毛细管截止阀的各种参数下的阀性能。(C)2004爱思唯尔B.V.保留所有权利。
This paper presents a simple and accurate method for characterizing pressure barrier of capillary stop valves inside micro sample separators based on active CD-like microfluidics platforms. The capillary stop valves and micro sample separator were fabricated on polycarbonate (PC) substrates by using hot embossing techniques. The capillary valves stop the flow of liquid inside the microfluidic devices using a capillary pressure barrier when the channel geometry changes abruptly. Experiments are performed by rotating micro sample separator on a platform. The liquid sample stopped inside the micro sample separator is expected to be segmented by using density gradient centrifugation. Various density segments of samples required for an analysis can be separated by simply rotating at different speeds. Design parameters of the capillary valves used in micro sample separator have been analyzed theoretically. It is shown that the pressure barrier of capillary valve design can be better predicted by using current modified 3-D meniscus model. Detailed theoretical analyses of valve behavior is presented and compared with experimental measurement. A model for the valve is then extracted that characterizes the valve performance for various parameters of capillary stop valves. (C) 2004 Elsevier B.V. All rights reserved.