Dsk Prachet, Fodor Petru S, Kothapalli Chandrasekhar R
Department of Aerospace Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Department of Physics, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44236, USA.
Micromachines (Basel). 2023 Jul 4;14(7):1373. doi: 10.3390/mi14071373.
Miniaturization of liquid chromatography could help enhance sensitivity, reduce solvent usage, and detect small quantities of peptides. However, it demands better sample homogenization of the mobile phase. We here developed a mixer design based on the inline Kenics geometry, consisting of a periodic arrangement of twisted blades placed inside a cylindrical capillary that repeatedly cut and stack fluid elements to achieve rapid mixing in laminar flow regimes. The mixer design was optimized with respect to the twist angle and aspect ratio of the mixing units to achieve complete mixing at minimum pressure load cost. Results suggest that for optimal designs, for a mixer volume of ~70 μL, complete mixing is achieved within a distance smaller than 4 cm for a broad set of flow rate conditions ranging from 75 μL·min to 7.5 mL·min. A salient feature that we introduce and test for the first time is the physical flexibility of the cylindrical capillary. The performance of the design remained robust when the mixing section was not rigid and bent in different topologies, as well as when changing the chemical composition of the mobile phase used.
液相色谱的小型化有助于提高灵敏度、减少溶剂用量并检测少量肽段。然而，这需要对流动相进行更好的样品均质化处理。我们在此开发了一种基于在线凯尼克几何结构的混合器设计，它由放置在圆柱形毛细管内的周期性扭曲叶片排列组成，这些叶片反复切割并堆叠流体单元，以在层流状态下实现快速混合。混合器设计针对混合单元的扭曲角度和纵横比进行了优化，以在最小压力负载成本下实现完全混合。结果表明，对于优化设计，对于体积约为70 μL的混合器，在75 μL·min至7.5 mL·min的广泛流速条件下，在小于4 cm的距离内即可实现完全混合。我们首次引入并测试的一个显著特征是圆柱形毛细管的物理柔韧性。当混合部分不刚性且以不同拓扑结构弯曲时，以及在改变所用流动相的化学成分时，该设计的性能仍然稳健。
