Medical Device Innovation Center, National Cheng Kung University, Tainan 70403, Taiwan.
Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung 84001, Taiwan.
Sensors (Basel). 2022 Jan 28;22(3):1028. doi: 10.3390/s22031028.
This study aimed to design and fabricate planar constricted-expanded structures that are integrated into paper-based channels in order to enhance their chaotic advection and improve their mixing performance. Chromatography papers were used to print paper-based microfluidics using a solid-wax printer. Three different constricted-expanded structures-i.e., zigzag, crossed, and curved channels-were designed in order to evaluate their mixing performance in comparison with that of straight channels. A numerical simulation was performed in order to investigate the mixing mechanism, and to examine the ways in which the planar constricted-expanded structures affected the flow patterns. The experimental and numerical results indicated that the proposed structures can successfully mix confluents. The experimental results revealed that the mixing indices () rose from the initial 20.1% (unmixed) to 34.5%, 84.3%, 87.3%, and 92.4% for the straight, zigzag, curved, and cross-shaped channels, respectively. In addition, the numerical calculations showed a reasonable agreement with the experimental results, with a variation in the range of 1.0-11.0%. In future, we hope that the proposed passive paper-based mixers will be a crucial component in the application of paper-based microfluidic devices.
本研究旨在设计和制造集成在纸基通道中的平面收缩-扩张结构，以增强其混沌对流并改善混合性能。采用蜡质打印机在色谱纸上打印纸基微流控装置。设计了三种不同的收缩-扩张结构，即之字形、交叉和弯曲通道，以评估它们与直通道相比的混合性能。进行了数值模拟以研究混合机制，并检查平面收缩-扩张结构对流动模式的影响方式。实验和数值结果表明，所提出的结构可以成功地混合汇流。实验结果表明，混合指数（Mixing Index）从初始的 20.1%（未混合）上升到直通道、之字形通道、弯曲通道和十字形通道的 34.5%、84.3%、87.3%和 92.4%。此外，数值计算与实验结果具有很好的一致性，变化范围在 1.0-11.0%之间。未来，我们希望所提出的被动式纸基混合器将成为纸基微流控装置应用的关键组成部分。
