• Micro and nano electro-mechanical systems (MEMS/NEMS) have completely changed human society in the past decades. Many devices that are taken for granted these days like smart phone, future car and drone would be unthinkable without them.
• The integration of various new kinds of materials, such as metallic glass and nanostructures into micro technologies allows us to create devices with novel performance and characteristics; examples include acoustic sensors and actuators, thermoelectric generators and wafer level packages.
• In collaboration with partners inside and outside Tohoku University, technologies are being developed that can be transferred to industry ranging from material integration and processes to packaging and reliability.

Wide collaboration in Microsystem technology is possible. We develop, implement and optimize processes, devices and systems until they are ready for use, keeping in mind reliability, yield and other important features for commercialization. We work with also with partners, such as Fraunhofer. Flexible interlinking of expertise and capacities with other research groups enables us to meet broad project requirements and create complex system solutions.

• 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 are developing a non-destructive testing method for the long range rapid inspection of metallic pipe using microwaves. The method propagates a microwave inside a pipe, and evaluates flaws appearing at the inner surface of the pipe on the basis of the reflection and transmission of the microwave. The method does not require scanning probes unlike conventional non-destructive methods, which enables one to inspect a pipe quite quickly. Our experimental validations have demonstrated the effectiveness of the method using a pipe as long as 30 m.

The NDT method proposed here is applicable when many pipes are inspected or conventional methods are not available due to pipe length and its configuration.

• 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.

• 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.

• 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.

• 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.

• 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.