We aim to give high thermal conductivity to glass, which is known as a material that does not conduct heat well, and to apply it to new fields.

If mixed with a high thermal conductive material, glass can be a good conductor of heat. However, all the advantages of glass, such as transparency and freedom of molding, are lost. In this research, we succeeded in developing a transparent glass with high thermal conductivity that retains its glassiness by adopting the strategies of high thermal conductivity MgO deposition and refractive index matching.

• Transparent
• Free molding
• Thermal conductivity ~ 3 W/(m K) [300% of that of window glass]

Heat dissipation management using glass [heat dissipating glass substrates, lenses, fibers, etc.]

• Fukuyama laboratory studies novel material processing based on chemical thermodynamics with high-temperature thermophysical property measurements. As examples, we are developing new crystal growth processes to bring a breakthrough in nitride-semiconductor devices, which are promising materials for next-generation optical devices applied in environmental, medical, bio and information technologies fields. Database of thermophysical properties of materials is needed for modeling heat and mass transports in materials processes.

A new thermophysical property measurement system is currently under development, which enables accurate measurements of heat capacity, thermal conductivity, emissivity, density and surface tension of high-temperature melts, utilizing electromagnetic levitation in a dc magnetic field.

• For further social development, it is required the miniaturization, weight saving, high performance of various devices. We study on fiber, particle reinforced polymer, metal, ceramic matrices composite materials using our knowledge about materials mechanics and numerical simulation such as finite element method. We recently address to develop multi-functionalized composite materials, which have high strength, super lightweight, energy harvesting function, damage monitoring function, biodegradable at the same time.

• We developed both pH and Cl- imaging plates, which can visualize the pH and Cl- concentration on metal surfaces in acidic environments. The pH range is from 3.0 to 0.5, and Cl- concentration up to 4 M can be measured. Fluorescent dyes are successively used for pH and Cl- imaging in the field of biology, but their sensitivity tends to be insufficient in acidic and/or highly concentrated chloride solutions. A glass plate with a sol-gel sensing layer, which contains a pH indicator or a Cl- sensitive florescent dye was fabricated and validated using the solutions with various pH values and Cl- concentrations. Changes in the pH and Cl- distribution on stainless surface in an acidic environment were measured quantitatively.

The newly developed imaging plates can be used to investigate the mechanism of various chemical reactions, such as corrosion, which occurs in an acidic environment. Micro-flow imaging using our sensing technique will be a promising approach to understand the catalytic chemistry of metal surfaces.
強調

• Ti anodizing technique has been offered for coloring the surface of Ti, and its mechanism is understood by light interference varied with the oxide thickness. A characteristic of this study is to control the crystallinity of the oxide, and its originality is to provide photo-induced characteristics to Ti and its alloys by controlling the electrochemical conditions differed from that of coloration technology. This study is aimed for controlling the surface of Ti by using a simple and easy, inexpensive technique and to fabricate high functional titanium materials.

Related to practical applications, it is considered as a use for environmental purification such as deodorization and water purification, biomaterial and antibacterial and structural titanium.

Colorful TiO2 Particle
https://www.t-technoarch.co.jp/data/anken_en/T19-849.pdf

Transition metal compounds are known to exhibit a wide variety of colors. Until now, it has been possible to color white titanium oxide by doping with transition metal ions, but it is difficult to avoid biotoxicity derived from transition metals.

• In the present invention, titanium oxide inorganic pigments that do not contain transition metals and have various colors such as white, yellow, red, gray, green, purple, black, and skin color have been realized.

New applications of titanium oxide pigments are expected in the cosmetics field, where biotoxicity is an issue.

• Conventional X-ray imaging methods that rely on X-ray attenuation cannot generate clear contrast in the observation of low-density materials such as polymers consisting of low-Z elements. However, the sensitivity to the materials can be improved drastically by X-ray phase imaging that detects X-ray refraction caused by the materials. X-ray Talbot or Talbot-Lau interferometry consisting of X-ray transmission gratings is now constructed in laboratories for X-ray phase imaging. X-ray phase tomography is also realized, enabling high-sensitive three-dimensional observation.
• X-ray phase imaging can be utilized for X-ray non-destructive testing of industrial products and baggage that cannot be checked conventionally.

We aim at appending a phase-contrast mode to micro-CT apparatuses and developing screening apparatuses in production lines.

• Electronic products can be operated not only by semiconductors but also by metal interconnections attached to the semiconductors. Required properties for the metal interconnections are ohmic contact, diffusion barrier property, adhesion with semiconductors, and low resistivity, corrosion resistance, process reliability. Our group has committed ourselves to develop new metals and processes to meet the needs of wide-ranged device producers with consideration of cost performance. Topics of our research include (1) Cu alloys to self-form a diffusion barrier layer in multilayer interconnection of Si devices, (2) Cu alloys to form a reaction-doping layer in IGZO oxide semiconductors, (3) Nb alloys to achieve mechanical and thermal reliability with good ohmic property for SiC power devices, (4) Cu alloys for transparent conductive oxide such as ITO, (5) screen-printable Cu paste lines for solar cells, etc..

Our research efforts are targeted at metallization and interconnections for advanced LSI, flat panel displays, touch panels, power modules, solar cells, and other electronic devices. Collaborators include material producers, equipment vendors, and device producers in the entire value chain of electronic products.

• Microstructure represents various kinds of heterogeneities in the metallic materials, i.e., grains, component phase, lattice defects and chemical inhomogeneity such as impurity/alloying elements. It can be modified through control of phase transformation/precipitation and deformation/recrystallization by adjusting compositions of materials and/or through processing routes (heat treatment, deformation). Such expertise in micro/nanostructure control is very important in production of current materials from viewpoints of energy saving and recycling in structural materials such as steels and titanium alloys.
• We attempt to apply more advanced control of micro/nanostructures, such as atomic structures of crystalline interfaces, chemistory in an atomic scale (e.g., segregation) and so on. Fundamentals of microstructure formation (thermodynamics, kinetics, crystallography) are examined both theoretically and experimentally to clarify key factors for microstructure control. Another important aspect in our research is the improvement of mechanical property by microstructure manipulation.

Possibilities to establish new functions (e.g., superplasticity, shape memory/superelasticity) as well as superior mechanical properties (e.g., ultrahigh strength with high toughness/ductility) is also explored.