Erdem Kaan, Ahmadi Vahid Ebrahimpour, Kosar Ali, Kuddusi Lütfullah
Mechanical Engineering Program, Graduate School of Science Engineering and Technology, Istanbul Technical University, Maslak, 34496 Istanbul, Turkey.
Mechanical Engineering Department, Faculty of Engineering and Natural Sciences, Istanbul Medeniyet University, Uskudar, 34700 Istanbul, Turkey.
Micromachines (Basel). 2020 Apr 14;11(4):412. doi: 10.3390/mi11040412.
Label-free, size-dependent cell-sorting applications based on inertial focusing phenomena have attracted much interest during the last decade. The separation capability heavily depends on the precision of microparticle focusing. In this study, five-loop spiral microchannels with a height of 90 µm and a width of 500 µm are introduced. Unlike their original spiral counterparts, these channels have elliptic configurations of varying initial aspect ratios, namely major axis to minor axis ratios of 3:2, 11:9, 9:11, and 2:3. Accordingly, the curvature of these configurations increases in a curvilinear manner through the channel. The effects of the alternating curvature and channel Reynolds number on the focusing of fluorescent microparticles with sizes of 10 and 20 µm in the prepared suspensions were investigated. At volumetric flow rates between 0.5 and 3.5 mL/min (allowing separation), each channel was tested to collect samples at the designated outlets. Then, these samples were analyzed by counting the particles. These curved channels were capable of separating 20 and 10 µm particles with total yields up to approximately 95% and 90%, respectively. The results exhibited that the level of enrichment and the focusing behavior of the proposed configurations are promising compared to the existing microfluidic channel configurations.
在过去十年中，基于惯性聚焦现象的无标记、尺寸依赖性细胞分选应用引起了广泛关注。分离能力在很大程度上取决于微粒聚焦的精度。在本研究中，引入了高度为90 µm、宽度为500 µm的五圈螺旋微通道。与原始的螺旋微通道不同，这些通道具有不同初始纵横比的椭圆形结构，即长轴与短轴之比为3:2、11:9、9:11和2:3。因此，这些结构的曲率在通道中呈曲线方式增加。研究了交替曲率和通道雷诺数对制备悬浮液中尺寸为10和20 µm的荧光微粒聚焦的影响。在0.5至3.5 mL/min的体积流速（允许分离）下，对每个通道进行测试，以在指定出口收集样品。然后，通过对颗粒计数来分析这些样品。这些弯曲通道能够分离20 µm和10 µm的颗粒，总产率分别高达约95%和90%。结果表明，与现有的微流控通道结构相比，所提出结构的富集水平和聚焦行为很有前景。
