Analysis and experiment of capillary valves for microfluidics on a rotating disk
Analysis and experiment of capillary valves for microfluidics on a rotating disk
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DOI：
10.1007/s10404-007-0196-x
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发表时间：
2008-05-01
影响因子：
2.8
通讯作者：
Lin, Mou-Gee
中科院分区：
文献类型：
--
作者：
Chen, Jerry M.;Huang, Po-Chun;Lin, Mou-Gee
本文给出了用于离心式微流体流量调节的毛细管爆破阀的压力屏障的解析表达式。该分析考虑了截面突然膨胀的矩形微通道中三维(3D)构型的界面能的变化。我们推导了一个简单的表达式来预测克服毛细管阀的临界爆破压力或转速。在不同截面尺寸(300和400微米宽，80~600微米深)和楔形角(30度~100度)的转盘上进行了与微通道集成的毛细管阀的实验。流经毛细管阀的半月面发展的流动可视化支持了为本分析所做的假设。毛细管阀爆裂转速的测量结果与简单公式的预测值吻合较好，但较大流道宽度和较大楔角的毛细管阀比预测值低近10%。
This paper presents an analytical expression of the pressure barrier in a capillary-burst valve for flow regulation in centrifugal microfluidics. The analysis considers variations of the interfacial energies at the meniscus of three-dimensional (3D) configuration in a rectangular microchannel with a sudden expansion in cross-section. We derive a simple expression that predicts the critical burst pressure or rotational speed to overcome the capillary valve. Experiments were carried out for capillary valves that were integrated with microchannels on a rotating disk having various cross-sectional dimensions (300 and 400 mu m in width and 80-600 mu m in depth) and wedge angles (30 degrees-100 degrees) of sudden expansion. The flow visualization of the meniscus development across the capillary valve supports the assumptions made for the present analysis. The measurements of burst rotational speeds for the capillary valves are in good agreement with the predictions by the simple expression except that those with a larger channel width and wider wedge angles are nearly 10% lower than the predicted values.