The fast growth of microfluidic applications based on complex fluids is a result of the unique fluid dynamics of these systems, enabling the creation of devices for health care or biological and chemical analysis. Microchannels designed to focus, concentrate, or separate particles suspended in viscoelastic liquids are becoming common. The key fluid dynamical issue on which such devices work is viscoelasticity-induced lateral migration. This phenomenon was discovered in the 1960s in macroscopic channels and has received great attention within the microfluidic community in the past decade. This review presents the current understanding, both from experiments and theoretical analysis, of viscoelasticity-driven cross-flow migration. Examples of promising microfluidic applications show the unprecedented capabilities offered by such technology based on geometrically simple microchannels and rheologically complex liquids.

中文翻译：

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悬浮液体粘弹性引起的颗粒迁移及其在微流体装置中的相关性

基于复杂流体的微流体应用的快速增长是这些系统独特的流体动力学的结果，能够创建用于医疗保健或生物和化学分析的设备。设计用于聚焦、浓缩或分离悬浮在粘弹性液体中的颗粒的微通道正变得越来越普遍。这种装置工作的关键流体动力学问题是粘弹性引起的横向迁移。这种现象是在 1960 年代在宏观通道中发现的，并在过去十年中受到了微流体界的极大关注。这篇综述从实验和理论分析两方面介绍了目前对粘弹性驱动的错流迁移的理解。