School of Electrical and Automation Engineering, Jiangsu Key Laboratory of 3D Printing Equipment and Manufacturing, Nanjing Normal University, Nanjing, 210023, China.
Lab Chip. 2020 Oct 7;20(19):3485-3502. doi: 10.1039/d0lc00714e. Epub 2020 Sep 10.
Inertial microfluidics has gained significant attention since first being proposed in 2007 owing to the advantages of simplicity, high throughput, precise manipulation, and freedom from an external field. Superior performance in particle focusing, filtering, concentrating, and separating has been demonstrated. As a passive technology, inertial microfluidics technology relies on the unconventional use of fluid inertia in an intermediate Reynolds number range to induce inertial migration and secondary flow, which depend directly on the channel structure, leading to particle migration to the lateral equilibrium position or trapping in a specific cavity. With the advances in micromachining technology, many channel structures have been designed and fabricated in the past decade to explore the fundamentals and applications of inertial microfluidics. However, the channel innovations for inertial microfluidics have not been discussed comprehensively. In this review, the inertial particle manipulations and underlying physics in conventional channels, including straight, spiral, sinusoidal, and expansion-contraction channels, are briefly described. Then, recent innovations in channel structure for inertial microfluidics, especially channel pattern modification and unconventional cross-sectional shape, are reviewed. Finally, the prospects for future channel innovations in inertial microfluidic chips are also discussed. The purpose of this review is to provide guidance for the continued study of innovative channel designs to improve further the accuracy and throughput of inertial microfluidics.
惯性微流控技术自 2007 年首次提出以来，由于其具有简单、高通量、精确操控和无需外部场等优点而受到了广泛关注。该技术在颗粒聚焦、过滤、浓缩和分离方面表现出了卓越的性能。作为一种被动技术，惯性微流控技术依赖于在中等雷诺数范围内非常规地利用流体惯性来诱导惯性迁移和二次流，这直接取决于通道结构，导致颗粒迁移到横向平衡位置或被困在特定腔室中。随着微加工技术的进步，在过去十年中已经设计和制造了许多通道结构，以探索惯性微流控的基础原理和应用。然而，惯性微流控的通道创新尚未得到全面讨论。在这篇综述中，简要描述了常规通道（包括直通道、螺旋通道、正弦通道和扩张-收缩通道）中惯性颗粒的操控及其基础物理原理。然后，回顾了近年来惯性微流控通道结构的创新，特别是通道模式的改进和非常规的横截面形状。最后，还讨论了惯性微流控芯片未来通道创新的前景。本综述的目的是为创新性通道设计的持续研究提供指导，以进一步提高惯性微流控的准确性和通量。
