Microfluidic diffusion diluter: bulging of PDMS microchannels under pressure-driven flow
Microfluidic diffusion diluter: bulging of PDMS microchannels under pressure-driven flow
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DOI：
10.1088/0960-1317/13/3/309
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发表时间：
2003-05-01
影响因子：
2.3
通讯作者：
Cremer, PS
中科院分区：
文献类型：
--
作者：
Holden, MA;Kumar, S;Cremer, PS
压力驱动流动期间微流体系统的膨胀可能是基于聚二甲基硅氧烷（PDMS）的设备的主要考虑因素。微通道横截面积可以作为流速和下游微通道位置的函数而发生巨大变化。这种几何灵活性导致预测这些系统的对流/扩散传输变得困难。我们之前引入了一个无量纲参数 kappa，用于表征刚性全玻璃系统中压力驱动流的对流和扩散行为。本文描述了对该概念的修改，以应用于非刚性系统，这是通过结合实验步骤来解释 PDMS/玻璃微系统中的膨胀来实现的。具体来说，通过荧光显微镜对通道高度的实验测量与上述理论相结合，以表征设备中单个位置的对流/扩散行为。这允许在该点确定参数 K 并应用于预测 PDMS 微系统后续部分中的流体流量。该程序应用于专为产生浓度梯度而设计的PDMS/玻璃微流体扩散稀释（muDD）装置。理论上预测的和实验测量的微系统内的浓度分布非常匹配。
The bulging of microfluidic systems during pressure-driven flow is potentially a major consideration for polydimethylsiloxane (PDMS)-based devices. Microchannel cross-sectional areas can change drastically as a function of flow rate and downstream microchannel position. Such geometrical flexibility leads to difficulties in predicting convective/diffusive transport for these systems. We have previously introduced a non-dimensional parameter, kappa, for characterizing convection and diffusion behavior for pressure-driven flow in rigid all-glass systems. This paper describes a modification of that concept for application to non-rigid systems, which is accomplished by incorporating an experimental step to account for the bulging in PDMS/glass microsystems. Specifically, an experimental measurement of channel height by fluorescence microscopy is combined with the aforementioned theory to characterize convective/diffusive behavior at a single location in the device. This allowed the parameter K to be determined at that point and applied to predict fluid flow in the subsequent portion of the PDMS microsystem. This procedure was applied to a PDMS/glass microfluidic diffusion dilution (muDD) device designed for generating concentration gradients. Theoretically predicted and experimentally measured distributions of concentrations within the microsystem matched well.