Effects of surface properties on droplet dynamics in digital microfluidic systems

微流体学，顾名思义，研究非常小体积的流体的行为。微流体技术的应用可以在生物技术实验室中找到，用于生化分析，用于清洁和高效能源的燃料电池，以及用于电子产品的微型热交换器。近年来，液滴被认为是下一代微流体技术，即所谓的数字微流体技术，它可以作为化学和生物化学反应中最小的反应器。在用于生物和生物化学分析的这种系统中，界面张力和表面润湿性通常用于流量计量、活化和控制。由于高的表面积与体积比，在数字微流体中必须仔细考虑微观固-流相互作用和相关的界面现象。然而，定量信息仍然不足，因此继续阻碍相关的工程应用。

Microfluidics, by name, studies the behaviors of fluids of very small volumes. Applications of microfluidics can be found in biotech lab-on-a-chips for biochemical analysis, fuel cells for clean and efficient energy, and micro heat exchangers for electronics. Recently, liquid droplets, which can function as the smallest reactors in chemical and biochemical reactions, are considered as the next generation microfluidic technology, or the so-called digital microfluidics. In such systems for biological and biochemical analysis, interfacial tension and surface wettability are usually employed for flow metering, activation, and control. Due to the high surface-area-to-volume ratio, microscopic solid-fluid interactions and related interfacial phenomena have to be considered carefully in digital microfluidics. However, quantitative information is still inadequate and hence continues to hinder relevant engineering applications.