Braess's paradox and programmable behaviour in microfluidic networks
Braess's paradox and programmable behaviour in microfluidic networks
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DOI：
10.1038/s41586-019-1701-6
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发表时间：
2019-10-31
期刊：
影响因子：
64.8
通讯作者：
Motter, Adilson E.
中科院分区：
文献类型：
--
作者：
Case, Daniel J.;Liu, Yifan;Motter, Adilson E.
微流体系统现在被精确地设计为可以执行越来越复杂的任务的小型化流体操纵装置。然而，由于微尺度流动的典型线性性质，它们的操作通常需要许多外部控制装置，这阻碍了集成控制机制的发展。在这里，我们通过设计微流体网络来解决这个困难，该微流体网络在施加的压力和流速之间表现出非线性关系，可以利用该非线性关系来仅通过操纵输入和/或输出压力来切换内部流动的方向。我们发现，这些网络实现使用刚性聚合物通道携带水表现出实验支持的流体模拟Braess的悖论，其中关闭一个中间通道的结果在一个较高的，而不是较低的，总流量。利用的行为是可扩展的，并且可以用于实现具有多个交换机的流路由。这些发现有可能推动微流体网络中内置控制机制的发展，从而促进便携式系统的创建，并在从可穿戴医疗技术到可部署空间系统等领域实现新的应用。
Microfluidic systems are now being designed with precision as miniaturized fluid manipulation devices that can execute increasingly complex tasks. However, their operation often requires numerous external control devices owing to the typically linear nature of microscale flows, which has hampered the development of integrated control mechanisms. Here we address this difficulty by designing microfluidic networks that exhibit a nonlinear relation between the applied pressure and the flow rate, which can be harnessed to switch the direction of internal flows solely by manipulating the input and/or output pressures. We show that these networks-implemented using rigid polymer channels carrying water-exhibit an experimentally supported fluid analogue of Braess's paradox, in which closing an intermediate channel results in a higher, rather than lower, total flow rate. The harnessed behaviour is scalable and can be used to implement flow routing with multiple switches. These findings have the potential to advance the development of built-in control mechanisms in microfluidic networks, thereby facilitating the creation of portable systems and enabling novel applications in areas ranging from wearable healthcare technologies to deployable space systems.