• Plasma sterilization has been developed as an alternative sterilization method due to its chemical activity, operation at low temperature and atmospheric pressure, low power consumption, low cost and safety. We have studied a mechanism of chemical species generation and transport in a plasma flow and, the sterilization efficacy and mechanism for several plasma sources at atmospheric pressure, such as a microwave plasma flow, a dielectric barrier discharge in a tube and a water vapor plasma flow. We already clarified that the damages of outer membrane and destructions of the cytoplasmic membrane of Escherichia coli by exposure to the microwave plasma flow. Fig. 1 shows the effect of plasma exposure on the E. coli. When the E. coli was exposed to the plasma, the height of the E. coli decreased and the potassium leakage of cytoplasmic material increased. For sterilization in a tube, we also clarified that an induced flow in the narrow tube by DBD transports chemical species and sterilize the whole inside surface of a tube as shown in Fig. 2. We hope to conduct collaborative research with a willing company for a practical application of this technology in industry.

• 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.