Satoshi Kishimoto

Microcreep deformation measurements by a moire method using electron beam lithography and electron beam scan

Microcreep deformations in pure copper specimens are studied by a new moire method. In this method, a fine micrograting prepared by electron beam lithography is used as a model grating, and a scanning exposure ofthe primary electron beam in a scanning electron microscope (SEM) as a master grating. The scanning exposure of the electron beam on the specimen with the model grating produces moire fringes of bright and dark lines formed in response to the different amounts of the emitted secondary electrons for each primary electron. This new method makes it possible to obtain a clear and fine moire fringe without an image-processing system and to observe the moire fringe pattern and the SEM image at the same time. By this method, the inhomogeneous microcreep deformations such as grain boundary sliding, coarse slip, and localized strain are measured with high accuracy. It is confirmed that the creep strain is nonuniform even in the same grain and the strain distribution is caused mainly by the grain boundary sliding.

In-plane deformation measurement using the atomic force microscope moiré method

In this paper, a new scanning moire method is developed to measure the in-plane deformation of mica using an atomic force microscope (AFM). Moire patterns are formed by the scanning line of the CRT in the AFM system, and the atomic lattice of the mica or high-orientated pyrolytic graphite (HOPG). The measurement principle and the techniques employed for grating preparation are described in detail. This new method is used to measure the residual deformation of a mica plate after irradiation by a Nd-YAG laser, and to determine the residual strain of HOPG under a tensile load. Some interesting results are obtained. The successful results verify the feasibility of this method for measuring deformation in the nanometre range using the lattice of the material as the model grid.

Characterization of planar periodic structure using inverse laser scanning confocal microscopy moiré method and its application in the structure of butterfly wing

An effective measuring method for characterizing the planar periodic structure on specimen surface, i.e., inverse laser scanning confocal microscopy moire method, is presented and verified by experiments in this paper. The planar character of the periodic surface structure in a large region of several hundreds of millimeters, as well as the dimension at micro- and nanoscales, can be obtained through seeking the specimen grating equation as well as the virtual strain distribution. Verification experiment is carried out using a 1200lines∕mm holography grating as the specimen. The calculated results are in good coincidence with the actual character, demonstrating the validity, feasibility, and high accuracy of this method. Applying this method into identifying the structure of butterfly wing, gratings composed of a cluster of curves with pitches of a little less than 438nm are found on multiscales of butterfly wing, which provides the possibility for further explaining its attractive iridescence. Furthermore...

Development of a pattern to measure multiscale deformation and strain distribution via in situ FE-SEM observations

We investigated a method for measuring deformation and strain distribution in a multiscale range from nanometers to millimeters via in situ FE-SEM observations. A multiscale pattern composed of a grid as well as random and nanocluster patterns was developed to measure the localized deformation at the specimen surface. Our in situ observations of a carbon fiber-reinforced polymer matrix composite with a hierarchical microstructure subjected to loading were conducted to identify local deformation behaviors at various boundaries. We measured and analyzed the multiscale deformation and strain localizations during various stages of loading.

Fabrication of high-frequency electron beam moiré grating using multi-deposited layer techniques

Abstract This paper proposed new ways for producing multi-layer model grids for electron beam moire method. An electron beam lithography system was set up under scanning electron microscope which was equipped with a beam blanking device and a pattern generator. The two-deposited-metal layers method was used to manufacture electron beam grating for high-temperature use. The results verify that the Zr–Pt-type grating possesses heat resistance up to 1100°C in vacuum. A new type of composite grating with frequencies 100 lines / mm and 1000 lines / mm using three deposited layers was produced. A 10 000 lines / mm two-deposited-metal layers grating was successfully fabricated using electron beam lithography.

Study of the surface structure of butterfly wings using the scanning electron microscopic moiré method

Scanning electron microscopic (SEM) moiré method was used to study the surface structure of three kinds of butterfly wings: Papilio maackii Menetries, Euploea midamus (Linnaeus), and Stichophthalma howqua (Westwood). Gratings composed of curves with different orientations were found on scales. The planar characteristics of gratings and some other planar features of the surface structure of these wings were revealed, respectively, in terms of virtual strain. Experimental results demonstrate that SEM moiré method is a simple, nonlocal, economical, effective technique for determining which grating exists on one whole scale, measuring the dimension and the whole planar structural character of the grating on each scale, as well as characterizing the relationship between gratings on different scales of each butterfly wing. Thus, the SEM moiré method is a useful tool to assist with characterizing the structure of butterfly wings and explaining their excellent properties.

Electron moiré method and its application to micro-deformation measurement

In this paper, the single and two deposited metal layers method were proposed to produce the model grating for electron moire method. The measurement principle of electron moire method and the techniques for manufacturing model grid are expounded in detail. The accuracy of measuring strain using this method is discussed. The gratings with single deposited layer and two deposited layers with high frequency up to 5000 lines/mm were produced on different substrates. From the experimental results, both single deposited metal layer and two deposited metal layers gratings showed their heat resistance ability. Using the gratings produced and a replicated model grid, the electron moire method was applied to measure the deformation of the strain around holes in a polyimide resin substrate, thermal strain of electronic packaging component and tensile creep around grain boundary in a pure copper specimen.

Three-directional structural characterization of hexagonal packed nanoparticles by hexagonal digital moiré method

We present the hexagonal digital moiré method for three-directional structural characterization of hexagonal packed nanostructures. A mismatch between a three-way grating and a nanoparticle assembly is shown to produce hexagonal moiré fringes due to the interference between three groups of parallel moiré patterns. The measuring principles of the pitches and the orientations of the three 1D arrays of the nanoparticles are presented. The structural information on a silica nanoparticle assembly is analyzed.

Simultaneous analysis of residual stress and stress intensity factor in a resist after UV-nanoimprint lithography based on electron moiré fringes

In this study, the residual stress in a resist (PAK01) film and the stress intensity factor (SIF) of an induced crack are simultaneously estimated during ultraviolet nanoimprint lithography (UV-NIL) based on electron moir? fringes. A micro grid in a triangular arrangement on the resist film fabricated by UV-NIL is directly used as the model grid. Electron moir? fringes formed by the interference between the fabricated grid and the electron scan beam are used to measure the displacement distribution around the tip of a crack induced by the residual stress in the resist. The SIF of the crack is estimated using a displacement extrapolation method. The residual strain fields and the corresponding residual stress in the resist film far from the crack are determined and analyzed. This method is effective for evaluating the grid quality fabricated by the UV-NIL technique.

The exploration of domain sizes and orientation directions in ordered assembled nanoparticles with electron Moiré fringes

Structural information such as domain sizes and orientation directions in ordered assembled nanoparticles can be simultaneously obtained by using generated electron Moiré fringes, without direct observation of the nanoparticles.