• A new dry-contact technique for transduction of broadband, high-frequency ultrasound via a solid layer inserted between water and the sample, whereat the pressure of about 0.1 MPa is applied at the layer/sample interface by evacuating air between them, has been developed. Based on the technique, acoustic imaging of an electronic package is realized under the dry environment (Fig. 1). Typically, the polymer films are used as the intermediate layer for water protection of the sample, and by utilizing the acoustic resonance phenomenon among water, film and the sample, higher quality acoustic image of the testing sample than that for the water immersion case can be recorded without getting the sample wet (Fig. 2). Moreover, thin materials, e.g., polymer film (Fig. 3), etc. can be characterized by analyzing the acoustic resonance phenomenon among the three media. We hope to conduct collaborative research with a willing company for a practical application of this technology in industry.

• 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.