Experimental Physics, Saarland University, D-66123 Saarbrücken, Germany.
Rep Prog Phys. 2012 Jan;75(1):016601. doi: 10.1088/0034-4885/75/1/016601. Epub 2011 Dec 22.
Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.
液滴微流控技术是一门快速发展的交叉学科领域，融合了软物质物理、生物化学和微系统工程学。其应用范围从快速分析系统或先进材料的合成，到蛋白质结晶和生物检测，再到活细胞的生物测定。液滴体积的精确控制和对单个液滴的可靠操作，如合并、混合其内容物以及与快速分析工具相结合的分类，使我们能够在定义的条件下在液滴内进行化学反应。在本文中，我们将回顾现有的液滴生成和操作技术。本综述的主要重点不是全面详细地解释所有技术，而是识别和阐明相似之处和潜在的物理原理。由于微流道的几何形状和润湿性是液滴生成的关键因素，我们还简要描述了基于液滴的微流控技术中的典型器件制造方法。还介绍了依赖于所讨论的操作技术的应用实例和反应方案，例如特殊材料的制造和生物物理实验。
