• Practical materials and devices are changed by the times. Their performances of the materials are generally improved by utilizing valuable elements. In the next generation, it is required that novel materials and devices are developed, whereas it appears that the quality of minerals and raw materials is degraded. We are taking several initiatives of research and development of high-efficient utilization of valuable elements.

We are promoting sound industry-academia collaboration by providing reliable research results and a number of true knowledge to many people based on the research achievements we have built up to now, and also by notifying related information.

• Toward the ultimate performances of image sensors, advanced research activities are being conducted that cover a wide range of technology fields from cleanroom infrastructure, materials, process equipment, process, device, circuit, assembly, signal processing, measurement/evaluation and reliability. Following technologies have been successfully commercialized:
• A fast and accurate measurement technology of electrical characteristics for over 1 million transistors
• A wide dynamic range CMOS image sensor technology capturing images over five decade brightness ranges
• An ultra-fast CMOS image sensor technology with 10 million frames/sec

Followings are available for industry collaborators:
A. 200mm-diameter-wafer silicon device fabrication utilizing the ultra-clean facility including wafer mutual fabrication processing between device manufacturers.
B. Process technology development and various kinds of analyses.
C. Development of new image sensors.

• This group is engaged in basic and applied researches of "hydrides" for practical use in hydrogen energy system. The main subject is the exploration of advanced hydrogen storage materials which support hydrogen energy technologies such as fuel cells. Currently, we synthesize a wide variety of novel hydrides composed of lightweight metals with specific nano-structures using advanced techniques for crystal and electronic structure analyses. In addition to the hydrogen storage, we develop the wide research fields related to hydrides, such as fast lithium ionic conductors.

Besides the contributions in industrial progress through the material development for future hydrogen energy system and next-generation secondary battery, we positively provide technical assistance to organizations and companies concerned about our findings.

• We are studying MEMS (Micro Electro Mechanical Systems) and related technologies, which are typically used for the input/output of information/communication devices, the safety of automobiles etc. Our representative topics include integrated sensors, piezoelectric devices, RF MEMS, micro energy devices and wafer-level packages. Our facilities are open-accessible and well equipped with a lot of tools for lithography, dry/wet etching, thin film deposition, wafer bonding, device mounting and evaluations, which can be operated by each researcher. Using these tools, a variety of MEMS are being prototyped. Also, new microfabrication tools are being developed by ourselves.

We are collaborating with many companies, from which visiting researchers are dispatched to our laboratory. We also accept companies which want to just use specific tools in our facilities. Consultation is always welcome.

• We invented supercritical hydrothermal synthesis method for the synthesis of organic modified nanoparticles (NPs). Under the supercritical state, the organic molecules and metal salt aqueous solutions are miscible and water molecule works as an acid/base catalyst for the reactions. Organic-inorganic conjugate NPs can be synthesized under this condition. This hybrid NPs show high affinity with the organic solvent or the polymer matrix, which leads to fabricate the organic inorganic hybrid nanomaterials with the trade-off function (super hybird nanomaterials). These hybrid materials of polymer and ceramics fabricated with NPs achieve both high thermal conductivity and easy thin film flexible fabrication, namely trade-off function.

For example, by the surface modification of BN particles by supercritical method, affinity of BN and polymers could be improved, so that high BN content of hybrid materials, thus high thermal conductivity materials, could be synthesized. Also by dispersing high refractive index NPs like TiO2 or ZrO2 into polymers transparently, we can tune the refractive index of the polymers. CeO2 nanoparticles are expected to be used for high performance catalysts. To transfer those supercritical fluid nano technologies, a consortium was launched with more than 70 companies.

• We are developing a new continuous flow type process for supercritical reactions. Under the supercritical state, the organic molecules and metal salt aqueous solutions are miscible and water molecule works as an acid/base catalyst which leads to rapid reactions. In order to apply such new reaction fields to an industrial process, it is necessary to establish the process design basis by understanding phenomena in the reaction fields, on the basis of phase equilibrium, flux and reaction kinetics theory. So while developing a process, we are doing research for the establishment of the process design basis.

Examples are a process for the synthesis of organic modified nanoparticles (MPs), a process for the pretreatment and solubilization of biomass in the supercritical/subcritical water and a process for the refinery of heavy oil in the supercritical water.

• Hybrid materials that show multi-functions of polymer and nanoparticles are expected to be used in future industries, and thus many research and development have been actively conducted. However, since the affinity of polymer and inorganic nanoparticles is very low, in most of the cases, properties of different materials are incompatible in the hybrid materials. To create the hybrid materials with incompatible multi-functions has been considered a difficult task.
• However, by using supercritical fluid technology, we have succeeded in making hybrid materials with incompatible multi-functions.

Now, variety of hybrid materials are being developed, including
・Transparent, flexible, high reflective index, and high fabricability,
・Flexible, high heat conductivity, low electric resistivity, and high fabricability.

• Our research group has succeeded in synthesizing various metal oxide nanoparticles with controlled size and exposure crystal planes by using organic modifiers under supercritical water conditions. The oxygen storage/release capacity of those materials in the low-temperature region is very high, and the reforming reaction of oxidative hydrocarbon proceeds at a significant rate. Besides, by combining the supercritical CO2 drying method, we have succeeded in forming a complex in which oxide nanoparticles are dispersed at a high concentration on the surface of the porous material, realizing both high oxygen storage/release capability and stability.

Low-temperature reforming reaction of biomass wastes, heavy oils, and methane. In the future, it is expected to be a technology that will lead to the construction of a low-carbon society, including CO2-free complete recycling of waste plastics.

• Scanning tunneling microscope (STM) and atomic force microscope (AFM) are among a few microscopes which enable a direct observation of atomic scale structures of materials. If compared with other electron microscope like transmission electron microscope (TEM), the energy of the electron used for STM is very low that has a big advantage of low damage for sample. Thus STM and AFM are regarded as the most important tools to characterize materials in nanotechnology. The research is now developing from a mere observation of the shape of material to the characterization specific properties of materials with an atomic scale resolution. These properties include spin and molecule vibration; well established techniques like ESR/NMR and infrared-spectroscopy requires more than billions of molecules to obtain data, while STM can obtain these data for a single molecule.
• We are interested following issues and like to have a collaboration with industrial companies.
• 1. Molecule-scale morphological characterization of soft-material, polymers and bio material.
• 2. Site specific vibration spectroscopy of molecules with an atomic resolution.
• 3. Single spin detection with ESR-STM method
• 4. Developing atom-scale characterization tool

• 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.