My research explores the mathematical connections between quantum mechanical scattering, nonlinear waves, and seismic waves to understand how mathematical methods and analysis can potentially gain new insights and develop novel approaches.
Finding and understanding the mathematical connections that exist between different fields and phenomena is what makes mathematical research so fascinating.

(1) Electric materials for the next 6G system
　We have synthesized a new polymer with the lowest dielectric constant in all-aromatic hydrocarbon-type polymers, and are developing it for electric materials of the next 6G system.

(2) Production of green hydrogen
　The catalysts and materials for production of green hydrogen are studied such as artificial photosynthesis and electrolysis of water by renewable energy.

(3) Secondary battery with ultra-high capacity
　The new cathode materials with ultra-high capacity in lithium ion battery are developped to increase driving distances for EV.

The aim of the research is to clarify the origin and evolution of the Solar System using various types of meteorite samples. Analytical techniques I am using for the studies are optical microscope, scanning electron microscope, electron probe micro analyzer (EPMA) and Micro Raman spectroscopy etc. Our target bodies are all of the celestial bodies include Earth. I am also joining the deep space exploration. My E/PO activities are exhibitions of meteorites and public lectures.

Graphene, integrated into the 3D nanoarchtecture with the smoothly interconnected curved surface, is promissing to clarify the novel properteis of the curved atomic layers adding to the amplifications of various material performance per unit projected area. We experimentally clarify the basic properties of the electrical transport on the 3D curved surface utilizing the high quality 3D graphene materials (so-called 3D nanoporous graphene). We also focus on the coexistence of the localized and itinerant electron properties originating from nitrogen-doping induced the local structural deformation of the 3D curved surface toward applications for the catalyst electrodes and thermoelectric materials using multifunctional electronic properties.

Conduction electrons in organic conductors behave simultaneously as quantum waves and classical particles. Due to the dual nature of these electrons, molecular solids demonstrate a variety of unconventional properties. Our group is investigating the possibility of finding a ferroelectric material that is polarized by a change of electron distribution, using techniques such as IR-Raman spectroscopy, nonlinear optics, and thermo-electric measurements. The unusual macroscopic polarization resulting from electron ordering could pave the way for future applications of organic solids in fast-switching devices and opto-electronic transducers.

Topology is a field of mathematics to study the properties of objects under continuous deformations. The classification of objects by means of number of the holes (corresponding to the topological number) indicates that a doughnut is identical with a mag with genus g=1. In topological materials whose wave functions are characterized by the topological number, electrons can move at very high speed near the edges. In contrast to conventional metals, they are less affected by defects in the crystal and/or impurities. Thus topological materials have received interest as highly functional materials toward next-generation devices.
We focus on topological materials and clarify the fundamental and transport properties, in which theoretical techniques such as the many-body quantum theory and the first principles methods are being applied to those.

Salmon milt, defatted soybeans, crab and shrimp shells, and cowhide have been discarded as an industrial waste around the world. Therefore, DNA, soy protein, chitin/chitosan, and collagen, which are obtained from these materials, are sustainable resources. Our research using sustainable resources is as follows; 1) removal of harmful organic compounds; 2) selective accumulation of metal ion; 3) development of anhydrous proton conducting material; and 4) development of bioplastic with the biodegradable property.

Metal complexes can exhibit functions and physical properties not achieved by organic or inorganic compounds alone by appropriately selecting the central metal ion and designing the organic π-electron ligands surrounding it. The characteristics of these complexes enable effective sunlight harvesting and various catalytic reactions utilizing its energy. In our laboratory, we are developing visible light-driven redox catalysts for photocatalytic H₂ production and CO₂ reduction using metal-porphyrin complexes, which can harvest visible light and catalyze various reactions. In research on functions and physical properties, we are developing coordination polymers with unique magnetic and dielectric properties based on mixed-valence states using redox-active ligands. Furthermore, we are developing one-dimensional d-electroninc metals based on partially oxidized one-dimensional dinuclear platinum complexes that exhibit stable metallic states at low temperatures.

Our research theme is development of new photoreaction using photoinduced electron transfer and its application to syntheses of functional materials. In present, we are working on (1) investigation of photochemical syntheses of indole derivatives which are considered to the important alkaloids widely found in nature, and (2) development of efficient photochemical synthetic methods for quinone imine dyes and their application. Because these target compounds indicate characteristic redox behavior, we also consider applying them to functional materials such as an OLED material while adopting their expected physical properties evaluated by quantum chemical calculation.

The kinds of polymers are relatively a few, which are used as plastics, rubber, and gels for daily life, since they exhibit versatile properties by hierarchical structure control ranging from nano- to micro-meter scales. In our laboratory, we focus to develop new polymeric materials by the hierarchical structure control and reveal the relationship between the mechanism and structure by microscope, scattering, and spectroscopy methods.

Developing efficient organic photovoltaic cell devices have been increasingly important in the growing needs for inexpensive renewable energy. The molecular designs for organic photovoltaic materials required delocalized pi-electron systems and utility elements. To develop novel pi-electron systems for organic photovoltaic materials, we synthesized some novel donor/acceptor arrays with aromatic bisimide units, and measured their properties and self-assembly abilities. Recently, we also synthesized some N-atom containing pi-electron systems and revealed their photophysical properties and structures.

The final goal of our research is to converse with ants. Ants have long been thought to engage in detailed communication using chemical substances such as pheromones. However, our researchis revealing that acoustic signals are also important toos of communication.We conducte detailed analyses of organs such as “ears” and “sound-producing organs”. It will be able to control the behavior of ants like leaf-cutting ants, which are significant damage against human society.

We have been collaborating with various stakeholders such as the Fukuoka City, Fukuoka Prefecture, and the Ministry of the Environment to control invasive alien ant species such as the red imported fire ant, the yellow crazy ant, and Argentine ant. In Okayama Prefcture, there have been reported of the little fire ant (Wasmannia auropunctata) at Mizushima Port, and we will continue to control and manage these ants.

By using silk produced by silworms, which domesticated in China 6,000 years ago, and the silks spun by black Japanese weaver ant in Okinawa, we conduct research to create new fabric sheets. We hope that as this research progresses, the black Japanese weaver ant can be a symbolic relationship with humans as the fourth demesticated insect.

The engine is an essential piece of machinery that is used in vehicles, electricity generators, ships, and so on. However, fossil fuels are limited in their amount and engines exhaust carbon dioxide from the burning of hydrocarbon-based fuels, which is treated as a cause of global warming. Therefore, in order to deal with these problems, an alternative fuel is proposed that is comparable to fossil fuel in terms of fuel properties such as ignitability, calorific value, cold flow properties and oxidation, but which is environmentally friendly. In this laboratory, a study is conducted on the production and optimal usage of alternative fuels such as biofuel (e.g., biodiesel), gaseous fuel, and so on. Combustion technology for engine systems for low fuel consumption rate using natural gas and hydrogen is also studied.

In order to improve the performance of various industrial devices and to make effective use of energy, it is important to understand and control the mechanisms of momentum, heat, and mass transport by turbulent flows. Understanding of turbulent transport phenomena is also essential for accurate prediction of meteorological phenomena. Our specific research topics include: experiments and numerical simulations to elucidate the mixing mechanism of scalars in liquid-phase turbulent jets; measurements of momentum, heat, and mass transport across wind-wave air-water interfaces to improve the prediction accuracy of typhoons; experiments to elucidate the behavior of droplets and bubbles in turbulent flows; and the development of novel devices (plasma actuators) to reduce fluid friction drag.

The mechanical and electro-magnetic characteristics of metals are dependent on microstructures such as crystal orientation and grain diameter. In recent years, comprehensive studies have been carried out on thermo-mechanical control processing to improve physical properties of metallic materials without adding rare elements in order to save energy and resources. For example, high performance metals, such as ultrafine grain steel and magnetic steel, are developed by a combination of rolling and heat treatment. These metals exhibit uniform characteristics. However, it is more efficient if suitable characteristics can be generated at required positions. In our research, a new technology to control only material surface microstructure is being studied.

In the case of metal materials are machined, the surface of materials are plastic defomed. Cristal structure of metal surface is strained by plastic deformation. The crystal structure strain changes the chemical property of surface. This phenomenon is called a mechano-chemical reaction. We study the mechano-chemical reaction and the relationship of machining process and material property.

1. Organic light-emitting materials for OLEDs or dyes for OPVs are developed.

2. Novel antiaromatic compounds such as Sondheimer-Wong diynes and diarenopentalenes are developed as new types of organic materials.

3. Organic syntheses using organotin cluster as catalysts are developed.

Numerical and experimental studies on transport phenomena, e.g. chemical reaction in beaker, indoor environment with air conditioner, natural environment, fluid flow and heat transfer in industrial equipment
■ patent number: 4931065
title of the invention: collision micro mixer
objective: increasing the chemical reaction efficiency by the collision of water and organic phases in the micro-channel
■ patent number 5504526
title of the invention: formation of slug flow with micro-reactor
objective: increasing the chemical reaction efficiency with the vortices generated by continuously changing the shapes of water and organic phases inside the micro-channel with zigzag walｌ

Recently, ε-Fe2O3 has attracted interest because of its magnetic potentiality, but there are some difficulties to straightforwardly obtain the pure/single ε-Fe2O3 phase. We have found that ε-Fe2O3 crystallizes epitaxially on crystals of mullite in our study on a Japanese traditional stoneware called “Bizen” . Since the particle morphology of ε-Fe2O3 and the relative ε-Fe2O3-to-mullite crystallographic orientation strongly depend on the oxygen partial pressure during firing and the temperature range, the formation conditions is very complicated. We believe that elucidating the formation mechanism of ε-Fe2O3 will contribute to the development of novel magnetic materials.
We are also working on the development of Al-B-C high-temperature structural materials. Ternary metal borocarbides, Al3BC3, have been considered as promising candidates for lightweight structural components. We have succeeded in synthesizing hexagonal plate-like Al3BC3 particles by a simple synthesis method, and the sintered sample exhibited anisotropic mechanical properties and higher bending strength due to particle orientation. Currently, we are proceeding with various physical property measurements.

In the design of public cultural facilities, there are an increasing number of examples of design methods that incorporate the users’ ideas at the architectural design stage in order to promote active use.
Our laboratory has collected 70 cases of participatory design from all over Japan. The following participatory design practices were implemented in our laboratory, and the effectiveness of participatory design was verified through analysis of user opinions and post-completion evaluations of these practices.
・Kudamatsu City Community Exchange Center (2013)
・Okayama Prefectural Doctor’s Hall (2015)
・Sanagouchi Village Office (2017)
・Kashiwa City Southern Neighborhood Center (2018)