School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Sci Rep. 2017 Jan 23;7:41153. doi: 10.1038/srep41153.
Sheathless particle focusing which utilises the secondary flow with a high throughput has great potential for use in microfluidic applications. In this work, an innovative particle focusing method was proposed. This method makes use of a mechanism that takes advantage of secondary flow and inertial migration. The device was a straight channel with arrays of arc-shaped grooves on the top surface. First, the mechanism and expected focusing phenomenon are explained using numerical simulation of the flow field and force balance. A simulation of particle trajectories was conducted as a reference, and then a series of experiments was designed and the effects of changes in particle size, flow rate and quantity of the groove structure were discussed. The microscopic images show that this particle focusing method performed well for different size particles, and the results agreed well with the theory and simulated results. Finally, the channel successfully concentrated Jurkat cells, which showed a good compatibility in the biological assay field. In this work, the arc-shaped groove channel was demonstrated to have the ability to achieve high-throughput, sheathless and three-dimensional particle focusing with simple operations.
无鞘流聚焦技术具有高通量的特点，利用二次流实现了微流控应用中的颗粒聚焦。本工作提出了一种创新的颗粒聚焦方法。该方法利用二次流和惯性迁移的机制。该装置为直通道，上表面排列有一系列弧形槽。首先，通过流场和力平衡的数值模拟解释了该机制和预期的聚焦现象。作为参考进行了粒子轨迹的模拟，然后设计了一系列实验，讨论了粒子尺寸、流速和槽结构数量的变化的影响。微观图像表明，该颗粒聚焦方法对不同尺寸的颗粒都能很好地聚焦，结果与理论和模拟结果吻合较好。最后，通道成功浓缩了 Jurkat 细胞，在生物检测领域表现出良好的兼容性。在这项工作中，弧形槽通道被证明具有简单操作实现高通量、无鞘和三维颗粒聚焦的能力。
