Kim Taehoon H, Hahn Young Ki, Kim Minseok S
CytoDx, Seongnam-si, 13486, Korea.
Biomedical Convergence Science & Technology, Industrial Technology Advances, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Korea.
Micromachines (Basel). 2020 Mar 4;11(3):269. doi: 10.3390/mi11030269.
Microfluidic paper-based analytical devices (μPADs) have been suggested as alternatives for developing countries with suboptimal medical conditions because of their low diagnostic cost, high portability, and disposable characteristics. Recently, paper-based diagnostic devices enabling multi-step assays have been drawing attention, as they allow complicated tests, such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), which were previously only conducted in the laboratory, to be performed on-site. In addition, user convenience and price of paper-based diagnostic devices are other competitive points over other point-of-care testing (POCT) devices, which are more critical in developing countries. Fluid manipulation technologies in paper play a key role in realizing multi-step assays via μPADs, and the expansion of biochemical applications will provide developing countries with more medical benefits. Therefore, we herein aimed to investigate recent fluid manipulation technologies utilized in paper-based devices and to introduce various approaches adopting several principles to control fluids on papers. Fluid manipulation technologies are classified into passive and active methods. While passive valves are structurally simple and easy to fabricate, they are difficult to control in terms of flow at a specific spatiotemporal condition. On the contrary, active valves are more complicated and mostly require external systems, but they provide much freedom of fluid manipulation and programmable operation. Both technologies have been revolutionized in the way to compensate for their limitations, and their advances will lead to improved performance of μPADs, increasing the level of healthcare around the world.
微流控纸基分析设备（μPADs）因其诊断成本低、便携性高和可一次性使用的特点，被提议作为医疗条件欠佳的发展中国家的替代方案。近来，能够进行多步分析的纸基诊断设备受到了关注，因为它们使诸如酶联免疫吸附测定（ELISA）和聚合酶链反应（PCR）等以前只能在实验室进行的复杂测试能够在现场进行。此外，纸基诊断设备的用户便利性和价格是相对于其他即时检测（POCT）设备的其他竞争优势，这在发展中国家更为关键。纸中的流体操控技术在通过μPADs实现多步分析中起着关键作用，生物化学应用的扩展将为发展中国家带来更多医疗益处。因此，我们在此旨在研究纸基设备中最近使用的流体操控技术，并介绍采用多种原理在纸上控制流体的各种方法。流体操控技术分为被动方法和主动方法。被动阀结构简单且易于制造，但在特定时空条件下的流量控制方面存在困难。相反，主动阀更复杂，大多需要外部系统，但它们提供了更大的流体操控自由度和可编程操作。这两种技术都在弥补自身局限性的方式上发生了变革，它们的进步将导致μPADs性能的提升，提高全球医疗保健水平。
