流动聚焦研究进展及其应用

流动聚焦(flow focusing)是一种毛细流动现象, 1998 年被正式提出. 其原理为从毛细管流出 的流体由另一种高速运动的流体驱动, 经小孔聚焦后形成稳定的锥形, 在锥的顶端产生一股微射 流穿过小孔, 射流因不稳定性破碎成单分散性的微滴. 该技术稳定、易操作、没有苛刻的环境条 件, 可以制备微米量级甚至数百纳米量级的液滴、气泡、颗粒和胶囊等微粒子, 在科技领域和工 程实际中都有重要的应用价值. 本文回顾了流动聚焦技术的研究进展, 包括实验、理论和数值模 拟, 并对其应用进行了简要评述, 最后对流动聚焦的发展趋势做出展望.

Progress and application of flow focusing

Flow focusing (FF) is one of capillary flows, which is first proposed in 1998, characterized by the formation of a steady meniscus in the core of an extensional high-speed fluid focused by a small hole when a fluid is injected through a capillary needle. A very thin jet is issued from the vertex of the meniscus, passes through the hole and breaks up into monodisperse droplets at a certain distance outside the hole. The FF technique is steady, controllable and does not require rigorous conditions in producin...