Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching
Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching
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DOI：
10.3390/mi11080773
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发表时间：
2020-08-01
期刊：
影响因子：
3.4
通讯作者：
Tsutsui, Hideaki
中科院分区：
文献类型：
--
作者：
Kalish, Brent;Tan, Mick Kyle;Tsutsui, Hideaki
纸基微流体装置是开发低成本、即时诊断工具的有吸引力的平台。随着纸基设备的检测化学变得更加复杂，需要更复杂的设备，通常需要将不同的液体或试剂顺序输送到反应区。大多数对流量控制的研究都集中在引入延迟。然而，由于蒸发增加导致样品损失，延迟流动可能是有问题的。我们报告了使用CO（2）激光均匀蚀刻纸的表面，以改变纸基微流体装置中的芯吸速度。这种技术可以使芯吸速度提高1.1倍，降低0.9倍。芯吸速度可以通过蚀刻纸的两面来进一步提高，导致芯吸速度比未蚀刻的通道快1.3倍。还将具有纵向激光蚀刻凹槽的通道与均匀蚀刻的通道进行比较，其中最重的凹槽通道比最快的双面蚀刻通道芯吸快1.9倍。此外，在包装胶带中密封通道的两侧导致最严重的蚀刻通道，单面、双面和沟槽，芯吸速度比未蚀刻通道快13倍以上。通过选择性地蚀刻各个通道，可以在不改变任何通道几何形状的情况下获得顺序流体输送的不同组合。激光蚀刻是一种简单的工艺，可以集成到设备的图案化中，并且不需要额外的材料或化学品，从而能够更好地控制纸基微流体设备的流量。
Paper-based microfluidic devices are an attractive platform for developing low-cost, point-of-care diagnostic tools. As paper-based devices' detection chemistries become more complex, more complicated devices are required, often entailing the sequential delivery of different liquids or reagents to reaction zones. Most research into flow control has been focused on introducing delays. However, delaying the flow can be problematic due to increased evaporation leading to sample loss. We report the use of a CO(2)laser to uniformly etch the surface of the paper to modify wicking speeds in paper-based microfluidic devices. This technique can produce both wicking speed increases of up to 1.1x faster and decreases of up to 0.9x slower. Wicking speeds can be further enhanced by etching both sides of the paper, resulting in wicking 1.3x faster than unetched channels. Channels with lengthwise laser-etched grooves were also compared to uniformly etched channels, with the most heavily grooved channels wicking 1.9x faster than the fastest double-sided etched channels. Furthermore, sealing both sides of the channel in packing tape results in the most heavily etched channels, single-sided, double-sided, and grooved, wicking over 13x faster than unetched channels. By selectively etching individual channels, different combinations of sequential fluid delivery can be obtained without altering any channel geometry. Laser etching is a simple process that can be integrated into the patterning of the device and requires no additional materials or chemicals, enabling greater flow control for paper-based microfluidic devices.