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  A total internal reflection fluorescence microscope is employed for observing the flow behavior of distilled water near the wall surface; this paper describes the observation methods and measurement results. In addition to the description of the evanescent wave illumination, the paper presents the features of this measurement method, which are obtained using an actual photograph of the particle images. The paper also describes test methods and test results of the relationship between the fluorescence intensity of the particles and the position of the particles. In addition, a method for determining the velocity profile of particle images is presented. The velocity profile near the wall surface is obtained from the integrated value of the particle tracking velocimetry data in the evanescent wave illumination. The obtained results for the velocity profile of distilled water are found to agree well with the two-dimensional Poiseuille velocity profile at 100 nm < z < 250 nm.

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  The author pays his special attention to formation process of wafer-thin liquid film, known as 'precursor film,' ahead moving macroscopic contact line of a droplet spreading on a solid substrate. The spreading droplet on the solid substrate is accompanied with the movement of a visible boundary line so-called ‘macroscopic contact line.’ The author’s group has applied a Brewster-angle microscopy (BAM) to detect the precursor film growing at an early stage of the spreading of the droplet. The author introduces some examples of such macroscopic and microscopic wetting phenomena.

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  In recent years our ability to study, visualize and engineer processes on the nano-scale has grown tremendously. This has led to great advances in our understanding of processes on the nano-scale, and has raised interesting possibilities for future technological development. This is particularly the case for nano-fluidics, with potential for the engineering of systems such as highly-efficient membranes and self-cleaning surfaces. Due to the small scales involved, experiment is highly challenging, and so simulation has come to play an important complementary role in our exploration of the nano-scale. In this article we therefore provide an insight into the properties of nano-scale flow, and how we might control it through our emerging ability for precision-engineered nano-scale structures. Furthermore, we give an overview regarding simulation of non-equilibrium flow on the nano-scale, and draw attention to emerging computational methods and remaining challenges.

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  In micro gas flows, some interesting phenomena at/near a wall, velocity slip, temperature jump, and thermal transpiration, play an important role; thus, the development of a measurement technique, which measure a physical quantity at a wall, is very important. The pressure-sensitive paint (PSP) technique has potential as a diagnostic tool for pressure measurement of a solid surface. However, the application of PSP to micro gas flow measurement is very difficult, because the conventional PSP is too thick and does not have sufficient spatial resolution. Pressure-sensitive molecular film (PSMF) with ordered molecular assemblies has been developed. PSMF is fabricated by the Langmuir-Blodgett method. We also developed a micro channel by the PDMS micro-molding technique with mixing a pressure-sensitive dye into PDMS: i.e., a micro channel fabricated by PSP, which is named PSCC. In this paper, we show the PSMF/PSCC fabrication procedure and the applicability of them to micro gas flow measurement.

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  Our body has left-right asymmetry of internal organs. In the mouse embryo, left-right asymmetry is established at 8.0 days after fertilization (E 8.0). At E 8.0, the node cavity that has motile cilia appears at the midline of the embryo. The cilia rotate in clockwise direction and generate leftward fluid flow. The leftward flow (nodal flow) breaks symmetry of body by controlling gene expression. In this work, we quantitatively visualized flow field of the nodal flow in wild type and ciliary mutant embryo. PIV analysis reveals that the local fluid flow is sufficient to break left-right symmetry of mouse embryo. This suggests that the node cells have sensitive system for fluid flow. We conclude that PIV is very powerful tool for dissecting biological issues.

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