(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.

Our laboratory explores new materials using AI as a core research theme. Materials are made from combinations of elements in the periodic table, and the number of possible combinations is nearly infinite—many useful materials remain undiscovered. Some of these may include superconductors, solar cells, thermoelectric materials, or quantum devices.
Superconductors, for example, have zero electrical resistance and could enable lossless power transmission and highly efficient energy devices. However, known superconductors only work at very low temperatures. Discovering room-temperature superconductors remains a major scientific challenge.
Traditionally, material discovery has relied on researchers’ knowledge and intuition. Today, AI technologies such as generative AI and machine learning can analyze large datasets of material properties and predict those of unknown compounds. This data-driven approach aligns well with modern physics, especially statistical and quantum mechanics.
In our lab, we build AI models trained on material databases to predict which chemical compositions or structures may have desirable properties. Promising candidates are synthesized and evaluated through experiments such as X-ray diffraction and resistivity measurements. Feedback from these experiments is used to improve the AI models.

Microscopes are very important tools for studying biological samples. However, most of the microscopes cannot measure the vibrational molecular imaging based on molecular information. At the moment, only two microscopes are measureable. One is the Raman microscope, and the other is IR microscope, those are complementary relations. But these are not perfect. Especially, the IR microscope has very low spatial resolution about 10 µm, because of the diffraction limit by the IR wavelength. This is a serious problem for a microscope. To solve this problem, we have developed IR super-resolution microscope with a sub-micrometer spatial resolution by using vibrational sum-frequency generation (VSFG) detection, and have reported the applications to various biological samples such as human hair, avian feather, living cells and so on. By using this microscope, we can observe not only the vibrational molecular image with high spatial resolution but also the molecular orientation and chirality images.

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.

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.

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.

Transient absorption spectroscopy measures the changes in the absorbance of short-lived species generated by photo-irradiation, and gives us the information about dynamic processes in materials or chemical compounds. Rate constants are also determined by measuring time-profiles of the concentration of excited molecules.
By using this method, we can investigate molecular dynamics after photo-irradiation.

Various industrial products are made of solid materials such as metals, polymers, and ceramics. Although all solid materials deform elastically and plastically when forces are applied, their deformation behavior strongly depends on deformation mechanisms. Therefore, it is indispensable to understand their deformation properties to produce useful machines and durable apparatuses. Our laboratory has been working on subjects that aim to apply solid materials for various engineering applications; clarification and evaluation of deformation properties of engineering materials, study on influences of microstructure upon deformation properties of solids, and development of new forming techniques.

Examination of production conditions for soft magnetic amorphous ribbons by liquid rapidsolidification method using precipitation hardening Cu alloy rolls. In this paper, we investigated that production conditions for amorphous ribbons by liquid rapid solidification method.

In recent years, composite and polymeric materials have been increasingly replacing conventional metallic materials in aerospace, civil, marine, rail and automotive industries. Some applications of composite and polymeric materials involve dynamically loaded components and structures. Therefore, there is a need to fully understand the dynamic behavior of composite materials for the analysis and design of composite and polymeric structures subjected to impact loadings. However, the mechanical properties of composite and polymeric materials under dynamic loading conditions are not well understood, because there are no standard impact test techniques.
Consequently, we experimentally and numerically examine the effects of strain rate on the compressive and tensile characteristics of composite and polymeric materials. High strain-rate stress-strain curves are obtained on the standard or modified split Hopkinson pressure bar (SHPB). Low and intermediate strain-rate ones are measured in an Instron testing machine.

Machine elements such as screws, gears, bearings, shafts, and springs are components needed for mechanisms. The performance improvement of machine elements is essential for that of the mechanical device. Therefore, in the machine design laboratory, we work toward the high performance and high strength of machine elements in terms of materials, machining, and surface treatments. Specifically, we are working on the performance evaluation of plastic gears using gear testing machines, the rolling contact fatigue life evaluation of bearings with a ball-on-disk contact tester, the sliding characteristic evaluation of steel using a high temperature tribometer.

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.

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.

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.

In order to ensure safety during construction and to assure quality and performance of buildings, I am conducting research on methods to predict and to evaluate deformation of ground and structures accurately.
Also, to reduce cost, period, and environmental load of re-building, I am researching survey or evaluation methods of existing piles and foundation design reusing them.
In case of disasters such as earthquakes or heavy rains, I quickly survey on site, analyse the cause of damage, and utilise the results for subsequent disaster prevention and mitigation.

The way of manufacturing is undergoing major changes. One of the changes is co-creation. Development of a new manufacturing method beyond the gap between the creator and the user is a big challenge.
In my laboratory, I am studying a method to eliminate the barriers between creators and users as much as possible using Stress Index, Virtual Reality and so on. And we aim to construct a place where co-creation is possible.

More than ten thousands people died caused fatal accidents in houses every year in Japan. Among them a number of the aged people died in falling down to flat floor even though without any steps. Floor slipperiness is usually represented as static friction coefficient at the slips in toe-off during last half of gait cycle. However, it is said that slips are also occurred at heel down to floor during first half of gait cycle. In order to evaluate floor slipperiness at heel down, it is necessary to measure the dynamic friction coefficient between footwear and floor under incremental vertical load during the heel down.
The wear of UHMWPE(ultrahigh molecular weight polyethylene) used in artificial joint is investigated more than 5 million cycles using joint simulator. The simulator is reproduced vertical load, flexion/extension, abduction/adduction and internal/external rotaion during gate cycle.

We are interested in the effects of the artificial environment of imaging systems on humans. We have studied both pros and cons effects. Examples of the good effects are viewers’ sense of power, immersion, and presence, in which the viewers feel as if they are in the space projected by the imaging system. The problem of quantifying these senses is that it is not possible to measure them with a measuring instrument. These characteristics related to human senses and sensitivity can quantified through subjective evaluations and questionnaires. At the same time, biometric measurements are performed to search for measurement items that may serve as biological indices. We are investigating the relationship between subjective evaluations and biological indices.
Conversely, undesirable effects are that a person watching 3D images or a shaky image may experience eye fatigue or a motion sickness. To clarify what can be done to minimize these undesirable effects, we are studying the relationship between the undesirable effects and presented images by subjective evaluations and biometric measurements. In this process, we measure eye movements, autonomic nervous system, and brain activity to quantify the degree of the undesirable effects. Based on these results, we have proposed measures to prevent and mitigate undesirable biological effects.

By taking advantage of pneumatic actuators that have features of higher force / mass ratio, lightweight and flexibility based on compressibility, we have developed low-cost wearable actuators and low-cost home-based rehabilitation devices that can be disposable after using it. Specifically, we developed a flexible pneumatic cylinder that can be used even if the cylinder bends. A spherical actuator that consists of two flexible pneumatic cylinders have been also developed as an application for portable rehabilitation device. We have also developed a low-cost wearable servo valve using buckled tubes, an artificial muscle with built-in displacement sensor and a pipe inspection robot using extension type flexible pneumatic actuators. In addition, aiming at globalization for students, all graduate students in our laboratory have presentation in international conferences.