Microfluidic technologies have a unique ability to control more precisely and effectively on two-phase flow systems in comparison with macro systems. Controlling the size of the droplets and bubbles has led to an ever-increasing expansion of this technology in two-phase systems. Liquid-liquid and gas-liquid two-phase flows because of their numerous applications in different branches such as reactions, synthesis, emulsions, cosmetic, food, drug delivery, etc. have been the most critical two-phase flows in microfluidic systems. This review highlights recent progress in two-phase flows in microfluidic devices. The fundamentals of two-phase flows, including some essential dimensionless numbers, governing equations, and some most well-known numerical methods are firstly introduced, followed by a review of standard methods for producing segmented flows such as emulsions in microfluidic systems. Then various encapsulated structures, a common two-phase flow structure in microfluidic devices, and different methods of their production are reviewed. Finally, applications of two-phase microfluidic flows in drug-delivery, biotechnology, mixing, and microreactors are briefly discussed.

与宏系统相比，微流体技术具有独特的能力，可以对两相流系统进行更精确，更有效的控制。控制液滴和气泡的大小已导致该技术在两相系统中的不断扩展。液-液和气-液两相流由于它们在不同分支中的大量应用，例如反应，合成，乳液，化妆品，食品，药物输送等，已成为微流体系统中最关键的两相流。这篇综述着重介绍了微流体装置两相流的最新进展。首先介绍了两相流的基本原理，包括一些基本的无量纲数，控制方程和一些最著名的数值方法，随后回顾了在微流体系统中生产分段流（例如乳液）的标准方法。然后审查了各种封装的结构，微流控设备中常见的两相流结构，以及不同的生产方法。最后，简要讨论了两相微流在药物输送，生物技术，混合和微反应器中的应用。