KIMURA Yasuhiro

Nagoya University
School of Engineering
Assistant Professor

Research fields

Mechanics of Materials
Mechanical Properties on Nanoscale
Crystal Growth

Research Interests

In-situ Transmission Electron Microscopic Analysis

Professional Memberships

The Japan Society of Mechanical Engineers
The Society of Materials Science, Japan
The Japan Institute of Electronics Packaging

Main research topics

 I am promoting research on metallic nanowires, which are one-dimensional structures on the nanoscale, with the major goal as familiar and widely used materials. Metallic nanowires are next-generation materials that are expected to revolutionize the functionality of materials by improving the performance of existing devices through the unique properties of their extremely small scale. For example, in terms of mechanical properties, it has been reported that an appropriate crystalline structure governed by grain size, crystal orientation, and dislocation density significantly improves the elasticity of the nanowire itself and exhibits 2-3% higher elastic strain, one order of magnitude higher than that of bulk materials. However, research on nanowire properties and their applications remain at the laboratory level. In order to promote the widespread use of nanowires, which have been slow to be put into practical use, it is necessary to intentionally control the geometry of the nanowire in terms of length, diameter, and shape, as well as the crystal structure, which determines the properties of the nanowires. I have proposed a unique nanowire fabrication technology that utilizes the atomic diffusion phenomena of metal atoms called electromigration, stress-induced migration, and thermomigration. Recently, I have been measuring the physical properties of nanowires through in-situ transmission electron microscope observation, predicting atomic migration behavior using finite element analysis, and analyzing nanowire growth behavior based on crystal growth principles. I am working to realize “small manufacturing” through research and development of basic technologies.

Representative papers

Yasuhiro Kimura, “Irregular bending growth of free-standing Al microwire by electromigration,” Acta Materialia 157 (2018) 276-287.

Yasuhiro Kimura, “Loss in discharging atoms through artificial hole for fabricating metallic micro/nanowire by electromigration,” 6 (2019) 18-00269(1)-(9)

Research URL

Laboratory Website

Global issues to be solved through this project

Migration-driven Nanoscale Metallic Additive Manufacturing for Metamaterial Fabrication

 Metamaterials are next-generation novel materials with their high potential to take the breakthrough with conventional wisdom. As the word “meta” means “transcending,” metamaterials are attracting attention. However, so far, metamaterials are rarely used in products and do not exist in our daily lives. The issue that hinders the widespread usage of metamaterials is the difficulty of fabrication of it. It is impossible to realize the functions of metamaterials unless achievement of three technical factors of “three-dimensional fabrication,” “periodic fabrication,” and “nanoscale fabrication.” This study develops a new technology, migration-driven nanoscale additive manufacturing technology. Atomic migration, physical phenomenon of atomic transportation induced by chemical potential difference, is a key driven technology of this system. By making full use of this atomic-scale control, it can break away from the Si-based process, which is the conventional metamaterial fabrication method, and aim at its industrial application.