In this article, the fabrication of single crystal silicon (SCS) nanowire (NW) structures and their novel characteristics are described. We have produced in-plane and out-of-plane SCS NWs by means of two different types of fabrication processes including wet and dry etching. In-plane SCS NWs were fabricated using nano-lithography based on a local anodization technique with an atomic force microscope (AFM). 200-nm-wide SCS NW bridges were realized on an active layer in a silicon-on-insulator (SOI) wafer. The strength that was measured by AFM bending testing was larger by 40 times than that of bulk SCS. Even at temperatures ranging from 373 to 573 K, the NWs showed plastic deformation with dislocation slips. Out-of-plane SCS NWs were fabricated using the combination of deep reactive ion etching (DRIE) and thermal oxidation. By DRIE, SCS nano-pillars with scalloping sidewalls were produced on a SCS wafer. Thermal oxidation and wet etching were carried out as the post-process; consequently 100-nm-diameter out-of-plane SCS NWs array without scallops was realized. The NWs with the tremendous aspect ratio of 160 showed very large elastic deformation originating from their own weight and sticking. Novel size effect phenomena occurred in the SCS NWs produced were discussed.

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    In this article, a new materials test technique for a micron-size beam specimen is described. We have designed and developed the materials test equipment. The specimen that was designed in consideration of a microelectromechanical systems mirror device consists of a mirror, two torsion beams, and a frame. The specimen was made of single crystal silicon fabricated by deep reactive ion etching. The combination of loading point and with or without rotation support enables us to carry out three different types of material tests that are pure torsion, torsion-bending combination, and doubly-clamped beam bending tests. The fracture strength was measured, and the influence of deformation modes on the strength was discussed.

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    Some metal thin films, for example, an Al thin film of about 1 to 2 μm thickness, are delaminated with bending like a polygonal shape during micro cutting. Several samples of Al thin film on Si wafer and some glasses were prepared and the relation between horizontal force and delamination phenomenon during micro cutting was studied. In addition, the possibility to develop quantitative adhesion test by using micro cutting method was considered. As a result, films were delaminated when the horizontal force reached at the critical force and the approximate delamination area was able to be calculated from the relation between horizontal force and delamination phenomenon. But to establish quantitative adhesion test by using micro cutting method, developing the method of evaluating the energy used only for delamination in the total energy provided by cutting blade is needed. Furthermore, to validate the evaluated energy by comparing with the one from other adhesion test, techniques of making samples those are used correctly in different adhesion tests are important.

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    An identification method with a sharp indentation for elastoplastic properties of film/substrate system is proposed. The method is based on extensive finite element computation on "soft film on hard substrate" cases indented with a sharp indenter. The method utilizes the substrate effect on load versus displacement relation in the indentation; this effect has often been regarded as undesirable. The computational results are expressed as response surfaces in a material parameter space. Based on the surfaces, and employing experimentally obtained load versus displacement relation, the elastoplastic properties of the film are identified. To determine the elastoplastic properties more accurately, it is important to use not only the loading curve but also the unloading curve. Numerical examples determined by this method for film/substrate system are given.

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    Slip casting process under the imposition of a magnetic field is an excellent way for crystal aligned material formation. To investigate the alignment behavior of crystals suspended in a solvent under the imposition of a magnetic field, X-ray was irradiated on the slurry composed of bismuth particles with polydimethlsiloxane under the different intensity of a static magnetic field. Here, bismuth was chosen as a sample material to examine the alignment behavior because it had relatively large anisotropy in magnetic susceptibility among metals and ceramics. The XRD intensity of bismuth (110) plane peak was intensified by imposing the magnetic field. This well agreed with the theoretical prediction. And both the attained time to the saturation of the XRD intensity of the bismuth (110) plane peak and the saturated value were a function of the magnetic field intensity. Therefore, the alignment behavior of the bismuth particles under the imposition of a magnetic field could be detected using this method. The effective magnetic susceptibility difference of the bismuth particles estimated by the time dependence of the XRD intensity of the bismuth (110) plane peak was small compared to that of the single crystal. This suggested that the bismuth particles might aggregate each other.

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    Microgaps formed by film lamination without bonding exhibit high electric breakdown strength. Poled PZT has extremely high polarization compared to a polymer electret. For this study, electret condenser sensors (FeECSs) were prepared with microgaps formed by film lamination and a poled PZT electret. Transmission properties of the prepared samples were examined when used as ultrasonic probes for soft media (natural rubber, silicone, and acrylic). Lamination of PFA and PPS film in the gap attenuated the resonant vibration of the PZT disk. That attenuation increased concomitantly with the number of film laminations. Addition of BN agglomerates at the interface between films in the gap increased the signal intensity of transmitted ultrasonic waves as well as the attenuation of the resonant vibration. Such improvement might result from the decrease in the contact area between the films in the gap. Some FeECS samples showed higher intensity and more of a rising edge slope of the signal than the piezoelectric sample showed, but time-degradation of the intensity was apparent: the rising edge slope of the signal decreased by around 40% after three days. Discharge in the electret (PZT) might cause time degradation, thereby necessitating improvement of the insulation of the ferroelectric ceramics.

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    It is extremely important to estimate the spatial location of sound source under various vibrations and noise phenomena. With this background, techniques for estimating the location of sound source as non-contact testing are widely used for understanding various vibrations and noise problems intuitively. In this study, our goal is to estimate spatial location of sound source by the combined method of MUSIC algorithm as well as Spatial Smoothing Processing (SSP) and scanning technique. In particular, the handy microphone array system for evaluating the performance of combined method was developed. This paper presents both the analysis method and performance of combined method, and demonstrates the performance tests for estimating the spatial sound source location. As a result, it is possible to estimate the spatial sound source location with high accuracy applying the combined method through a series of experimental and computational examinations.

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