Capillary pumps for autonomous capillary systems
Capillary pumps for autonomous capillary systems
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DOI：
10.1039/b609813d
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发表时间：
2007-01-01
期刊：
影响因子：
6.1
通讯作者：
Delamarche, Emmanuel
中科院分区：
文献类型：
--
作者：
Zimmermann, Martin;Schmid, Heinz;Delamarche, Emmanuel
自主毛细管系统是许多生物分析应用的高效、快速和方便的平台，它通过毛细管来置换液体。要使这些微流控装置正常工作，需要用精确的流速置换准确体积的液体。在这项工作中，我们展示了如何设计毛细管泵来控制CS的流动特性。毛细管泵包括尺寸从15-250微米的各种形状的微结构，它们被放置在毛细管泵中以编码所需的毛细压力。毛细管泵被设计成具有小的流动阻力，并且前面有一个狭窄的微通道，该微通道起到流动阻力的作用。因此，毛细管泵和流动阻力都定义了CS中的流量，并获得了0.2nL-3.7nL S(-1)的流量。毛细管泵中微结构的位置和形状用于调整毛细管泵中液体的填充前沿，以获得可靠的填充行为，并将卷吸空气的风险降至最低。例如，填充前端可以垂直定向或倾斜到毛细管泵的主轴。我们还展示了如何连接具有不同流体力学性质的毛细管泵，以编程CS中的一系列慢速和快速流。
Autonomous capillary systems (CSs), where liquids are displaced by means of capillarity, are efficient, fast and convenient platforms for many bioanalytical applications. The proper functioning of these microfluidic devices requires displacing accurate volumes of liquids with precise flow rates. In this work, we show how to design capillary pumps for controlling the flow properties of CSs. The capillary pumps comprise microstructures of various shapes with dimensions from 15-250 mu m, which are positioned in the capillary pumps to encode a desired capillary pressure. The capillary pumps are designed to have a small flow resistance and are preceded by a constricted microchannel, which acts as a flow resistance. Therefore, both the capillary pump and the flow resistance define the flow rate in the CS, and flow rates from 0.2-3.7 nL s(-1) were achieved. The placement and the shape of the microstructures in the capillary pumps are used to tailor the filling front of liquids in the capillary pumps to obtain a reliable filling behaviour and to minimize the risk of entrapping air. The filling front can, for example, be oriented vertically or tilted to the main axis of the capillary pump. We also show how capillary pumps having different hydrodynamic properties can be connected to program a sequence of slow and fast flow rates in a CS.