• One of the important challenges in the development of carbon nanotubes (CNTs) reinforced ceramic composites is uniform dispersion of CNTs in the matrix. The mechanical properties of CNT/ceramics composites have been limited to date due to the formation of CNT agglomerates in the composite. We have successfully produced CNT/alumina composites with world top class strength and toughness, by employing a newly developed CNTs dispersion technique based on a flocculation method. The processing method developed in this study enables us to prepare high performance CNT materials using a pressureless sintering method.

The possible applications of the CNT/alumina composites developed in this study include tribological materials (ball bearing), biomaterials (artificial hip joint), micro-actuator materials utilizing electrostrictive effects, electromagnetic wave absorber, particularly in the frequency range of several GHz and several ten GHz.

• General metallic biomaterials, such as stainless steels and conventional CoCr alloys, show a high Young's modulus ten times higher than that of human bones. This is an unfavored feature because it causes the so-called "stress shielding effect" when they are used as implants. β-type Ti alloys have a relatively lower Young's modulus, but they come with a compromise of low wear resistance. The current novel CoCr-based alloys are a breakthrough; they exhibit both a low Young's modulus similar to human bones and a high wear and corrosion resistance. Moreover, they exhibit superelasticity with a huge recoverable strain over 17%, also showing promise as shape memory alloys.

It is the first time that a low Young's modulus, a high corrosion and wear resistance, and a superior superelastic behavior are simultaneously obtained in a single material. The current novel CoCr-based alloys are promising for biomedical applications such as total hip or knee joint replacements, bone plates, spinal fixation devices, and vascular stents.

• For producing a new functionality from metallic micro and nano matarials, the welding and cutting technologies for small scale materials utilizing Joule heat has been developed (Fig. 1). A constant direct current is supplied to the system, where the free ends of two metallic wires are contacted, and the ends are successfully welded together in self-completed manner. This technology is also useful for manipulating a small scale materials.

Joule heat welding technology enables us to produce the functional elements on the electrode chips, e.g., a free-standing micro-ring and very-thin thermoelectric element (Fig. 2). Moreover, we have developed the technique for characterizing the physical properties of small scale materials (Fig. 3). We hope to conduct collaborative research with a willing company for a practical application of this technology in industry.

• Intergranular degradation often results in decreased lifetime, reliability and economical efficiency of polycrystalline materials. In spite of persistent efforts to prevent such degradation, its complete suppression has not yet been achieved. Grain boundary studies have revealed that coincidence-site-lattice (CSL) boundaries have stronger resistance to intergranular degradations than random boundaries. The concept of ‘grain boundary design and control' has been refined as grain boundary engineering (GBE). GBEed materials which are characterized by high frequencies of CSL boundaries are resistant to intergranular degradations. Our group has achieved very high frequencies of CSL boundaries in commercial stainless steels by GBE. GBEed stainless steels showed significantly stronger resistance to intergranular corrosion (see Figs. 1 and 2), weld-decay, knife-line attack, stress corrosion cracking, liquid-metal embrittlement, radiation damage, etc. and much longer creep life (see Fig. 3) than the unGBEed ones.

By using this GBE processing, we expect to conduct effective collaborative research in related fields.

• To apply the specific properties of nano materials for the industrial products, various technologies, such as synthesis method for single phase alloy nanoparticles which shows the effective activity for aimed reaction, that for well crystallized alloy nanoparticles which shows the resistively against for undesirable reaction, and that for single layered surface control method, etc, is developed by precise control of metal complexes in the solution by using the calculation and various research equipment including the photon factory.

Our technology can be useful for various industry which need the restrict control of surface properties, such as catalysts and electronics.

• The aim of our research are to obtain the high accuracy sensor system for the signals from the human body or electric devices and to obtain the system for approaching action to the human body by using the nano-scale controlled magnetic materials and by the development of the devices under the functions of the magnetics.
• We studied the mechanism of obtaining the magnetic anisotropy of the magnetic thin films for the sensitive magnetic sensors. We obtained a non-metal probe for high frequency magnetic field, and confirmed the probe can measure the high frequency magnetic field with its phase information. In addition, 3D position detecting system using magnetic markers was studied to improve its position accuracy. The study about the magnetic actuator driven by the external magnetic field was carried out for biomimetic robots using the rotational magnetic field, and small wireless pumps were obtained and clarified for their application for an artificial heart-support pump.

<Medical Applications>
Motion system for capsule endoscope, Support system for endoscopic surgery, Position detecting system (motion capture), Wireless pump for artificial heart
<Sensors>
Magnetic field sensors, Strain sensors, Wireless sensors
<Materials>
Electrical steels of ultra low loss, Electrochemicaly produced materials (structure controlled in nano-scale)

• 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.

• We successfully realized millisecond-order X-ray phase tomography using a fringe-scanning method in grating-based X-ray interferometry. We obtained phase tomograms with a measurement time of 4.43 ms using a white synchrotron X-ray beam. The use of a fringe-scanning method enables us to achieve not only a higher spatial resolution but also a higher signal-to-noise ratio than that attained by the Fourier transform method. In addition, our approach can be applied to realize four-dimensional or high-throughput X-ray tomography for samples that can be rotated at a high speed.