Papers by Author: Hironori Tohmyoh

Abstract: Migration of atoms is presented to be utilized for fabrication of metallic micro/nanomaterials by controlling the phenomenon. Two kinds of migration phenomena are treated; one is electromigration and the other is stress migration. In addition to the formation of micro/nanomaterials, some achievements in enhancing their functions are demonstrated. One is a technique to fabricate nanocoils from the formed Cu nanowires. The others are techniques to weld or cut the micro/nanowires by using Joule heating. Finally, regarding evaluation of mechanical and electrical properties of the micro/nanomaterials, the concentrated-mass cantilever technique in atomic force acoustic microscopy and the four-point atomic force microscope technique are shown to be powerful tools, respectively.

Abstract: An acoustic resonant spectroscopy technique for measuring the acoustic impedance of micron-scale polymer films without knowing any values of ultrasonic velocity, thickness and density has been developed. The method, which is based on spectral analysis, observes the acoustic resonance between water, the film and a tungsten plate with high acoustic impedance. The acoustic impedances of poly(vinyl chloride), poly(vinyl alcohol) and nylon films are determined by the spectroscopy technique. Moreover, the values of ultrasonic velocity and density of the films are also determined from the resonance frequencies of the films.