Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, USA.
Lab Chip. 2013 Mar 21;13(6):1165-71. doi: 10.1039/c2lc41259d.
Microfluidic and nanofluidic devices have undergone rapid development in recent years. Functions integrated onto such devices provide lab-on-a-chip solutions for many biomedical, chemical, and engineering applications. In this paper, a lab-on-a-chip technique for direct visualization of the single- and two-phase pressure-driven flows in nano-scale channels was developed. The nanofluidic chip was designed and fabricated; concentration dependent fluorescence signal correlation was developed for the determination of flow rate. Experiments of single and two-phase flow in nano-scale channels with 100 nm depth were conducted. The linearity correlation between flow rate and pressure drop in nanochannels was obtained and fit closely into Poiseuille's Law. Meanwhile, three different flow patterns, single, annular, and stratified, were observed from the two-phase flow in the nanochannel experiments and their special features were described. A two-phase flow regime map for nanochannels is presented. Results are of critical importance to both fundamental study and many applications.
近年来，微流控和纳流控器件得到了快速发展。此类器件上集成的功能为许多生物医学、化学和工程应用提供了芯片实验室解决方案。在本文中，开发了一种用于直接可视化纳米尺度通道中单相和两相压力驱动流的芯片实验室技术。设计和制造了纳流控芯片；开发了浓度相关的荧光信号相关技术，用于确定流速。进行了具有 100nm 深度的纳米尺度通道中的单相和两相流实验。获得了纳米通道中流速和压降之间的线性关系，并与泊肃叶定律吻合良好。同时，从纳米通道中的两相流实验中观察到了三种不同的流动模式，即单相流、环空流和分层流，并描述了它们的特点。提出了纳米通道的两相流态图。研究结果对于基础研究和许多应用都具有重要意义。
