Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA.
Science. 2014 Jun 27;344(6191):1496-500. doi: 10.1126/science.1253618.
Nanofluidics involves the study of fluid transport in nanometer-scale structures. We report the direct observation of fluid dynamics in a single zinc oxide nanotube with the high spatial and temporal resolution of four-dimensional (4D) electron microscopy. The nanotube is filled with metallic lead, which we melt in situ with a temperature jump induced by a heating laser pulse. We then use a short electron pulse to create an image of the ensuing dynamics of the hot liquid. Single-shot images elucidate the mechanism of irreversible processes, whereas stroboscopic diffraction patterns provide the heating and cooling rates of single nanotubes. The temporal changes of the images enable studies of the viscous friction involved in the flow of liquid within the nanotube, as well as studies of mechanical processes such as those that result in the formation of extrusions.
纳米流体学涉及在纳米尺度结构中研究流体输运。我们报告了使用具有四维（4D）电子显微镜的高时空分辨率，直接观察单个氧化锌纳米管中的流体动力学。该纳米管中填充有金属铅，我们使用加热激光脉冲诱导的温度跃变将其原位熔化。然后，我们使用短电子脉冲创建热液随后动力学的图像。单次拍摄图像阐明了不可逆过程的机制，而频闪衍射图案则提供了单个纳米管的加热和冷却速率。图像的时间变化使我们能够研究液体在纳米管内流动所涉及的粘性摩擦，以及机械过程的研究，例如导致挤出物形成的过程。
