A fast, reconfigurable flow switch for paper microfluidics based on selective wetting of folded paper actuator strips
A fast, reconfigurable flow switch for paper microfluidics based on selective wetting of folded paper actuator strips
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DOI：
10.1039/c7lc00620a
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发表时间：
2017-11-07
期刊：
影响因子：
6.1
通讯作者：
Pandey, Santosh
中科院分区：
文献类型：
--
作者：
Kong, Taejoon;Flanigan, Shawn;Pandey, Santosh
在纸张微流体中，智能和多功能开关的开发对于调节多个通道中的流体流动至关重要。过去制造开关的方法受到长响应时间、大致动流体体积和使用外部控制电路的限制。我们寻求通过开发一种独特的致动器装置来缓解这些困难，该装置完全由层析纸制成，并与折叠结合在一起。在波峰或波谷用致动流体选择性地润湿折叠，用于升高或降低致动器的尖端，从而接合或断开通道之间的流体接触。在这里，执行器的响应时间大大缩短(从润湿开始的两秒内)，并且消耗了非常少量的执行液(4微升)。利用这种驱动原理，我们实现了单刀单掷(常断和常开)和单刀双掷(单断和双断)六种开关形式。通过并行使用六个执行器，建立了一种自主比色分析方法来检测人工唾液中三种分析物-葡萄糖、蛋白质和亚硝酸盐的存在。最后，这项工作将折纸的概念带到了纸张微流体中，其中可以利用多折叠几何结构来实现流体连接的可编程切换。
In paper microfluidics, the development of smart and versatile switches is critical for the regulation of fluid flow across multiple channels. Past approaches in creating switches are limited by long response times, large actuation fluid volumes, and use of external control circuitry. We seek to mitigate these difficulties through the development of a unique actuator device made entirely out of chromatography paper and incorporated with folds. Selective wetting of the fold with an actuation fluid, either at the crest or trough, serves to raise or lower the actuator's tip and thus engage or break the fluidic contact between channels. Here the actuator's response time is dramatically reduced (within two seconds from wetting) and a very small volume of actuation fluid is consumed (four microliters). Using this actuation principle, we implement six switch configurations which can be grouped as single-pole single-throw (normally OFF and normally ON) and single-pole double-throw (with single and double break). By employing six actuators in parallel, an autonomous colorimetric assay is built to detect the presence of three analytes - glucose, protein, and nitrite - in artificial saliva. Finally, this work brings the concept of origami to paper microfluidics where multiple-fold geometries can be exploited for programmable switching of fluidic connections.