Projects
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Research and Development of Anomaly Detection Technology for Civil Infrastructures Using Electret Vibrational Energy Harvesting Device and Wireless Power/Data Transfer
We will develop a battery-less anomaly detection device capable of sensing the condition and environment of infrastructure structures, and establish a wireless energy and data communication platform. In particular, a system will be realized that allows monitoring via an IoT network using microwave spatial transmission (WPDT) technology of information related to structural deterioration, damage, environmental conditions, and faults autonomously detected by electret MEMS sensors powered by environmental vibration energy harvesting. This will enable the social implementation of a seamless monitoring platform targeting infrastructure structures and their auxiliary facilities, capable of phase-free response at all times, including both normal and emergency conditions.
Katsufumi Hashimoto (PI), Hiroyuki Mitsuya, and Teruo Fujiwara
Material Behavior and Mechanical Performance Based on Hierarchical Structure Formation of 3D-Printed Concrete
This study investigates the hierarchical structure of 3D-printed concrete (3DP concrete) by analyzing two key aspects: the microscopic heterogeneity caused by material segregation within the filament during deposition, and the macroscopic non-uniformity resulting from interfacial voids formed along the printing path. By clarifying these higher-order structures, we demonstrate that 3DP concrete possesses multiscale material properties and mechanical behavior, making it a hierarchical material. Furthermore, we establish a systematic academic framework for understanding how heterogeneity (material geometry) and non-uniformity (structural geometry) are embedded as geometric parameters in 3D spatial information, providing insights into the mechanical performance and failure modes of 3DP concrete.
Katsufumi Hashimoto, Takafumi Sugiyama, and Shimpei Ono
Grant-in-Aid for Scientific Research(B) 2025.4.1～2028.3.31
Development of radiation technology to clarify the microstructure of concrete, which is becoming more diverse in a decarbonized society
Concrete, the main construction material, is the second most widely used substance after water. As concrete has a large environmental impact on a global scale, we are conducting research at the ultrafine level of its internal structure of concrete using advanced radiation technology to develop a new type of concrete that reduces the emissions of carbon dioxide and other gases that accompany its manufacture, without compromising its strength or durability. In this way, we can achieve a decarbonized society.
Takafumi Sugiyama, Katsufumi Hashimoto, and Michael Angelo B. Promentilla,
Grant-in-Aid for Scientific Research(B) 2025.4.1～2028.3.31
Development of dimension reduction scheme for data assimilation using criticality experiments
The nuclear cross section uncertainty given as a covariance matrix will be used to evaluate the realistic range of important parameters in the safety analysis of nuclear reactors. In recent discussions, the application of data assimilation is considered important to incorporate criticality experiment findings. However, there is a practical issue to treat the covariance matrix after applying data assimilation because the covariance matrix becomes much denser one by causing complex correlated components and the computational cost becomes increased. This research project develops a dimension reduction scheme to solve this practical issue.
Principal investigator: Tatsuya Fujita, and Collaborator: Go Chiba
Grant-in-Aid for Scientific Research(C) 2025.4.1～2029.3.31
Study of Quantum Plasticity and Supersolidity of solid 4He by Observing Motion of Sinking Object
Solid helium is often referred to as quantum solid and known to deform easily and rapidly even under tiny force, strongly subjected to quantum effect. A number of research have been conducted to study its elasticity, or reversible deformation, but its plasticity, or irreversible deformation, is scarcely understood. In the proposed experiment, we are going to precisely measure the motion of objects sinking in solid helium to elucidate the quantum effects on the plasticity of solid helium. Especially, the local superflow expected to exist in cores of dislocations and grain boundaries are to be examined, in the context of supersolidity.
Grant-in-Aid for Early-Career Scientists 2025.4.1～2028.3.31
Mechanisms underlying the dynamic strength of cancellous bone based on the impact strength of individual trabeculae and microarchitecture
Osteoporotic fractures occur in cancellous bone due to even minor impacts. In addition to bone mass, the impact strength of individual trabeculae and the microarchitecture are hypothesized to determine the dynamic strength of cancellous bone. This study aims to experimentally clarify these mechanisms and apply the findings to further improve the control of dynamic fracture risk.
Satoshi Yamada, Tomohiro Shimizu and Kazuhiro Fujisaki
Grant-in-Aid for Scientific Research(B) 2025.4.1～2028.3.31
Development of a 3D-printable head protection material with superior impact absorption and durability using biomimetic porous structures
We are developing a novel 3D-printable head protection material using a biomimetic structure inspired by cancellous bone architecture. This offers excellent multi-impact absorption capabilities. Its high three-dimensional isotropy enables it to absorb impacts from any direction. The porous design can be freely tailored to meet specific shape and performance requirements. In addition to head protection, the material shows strong potential for applications in body protection gear and cushioning materials for transporting precision equipment.
Satoshi Yamada, Yuelin Zhang, and Keita Kawashima
Adaptable and Seamless Technology transfer Program through Target-driven R&D (A-STEP) 2024.12.1～2027.3.31
Novel continuous-time crystallinity observed in a superfluid dripping system
While the dripping period of a classical viscous fluid is widely distributed due to the influence of chaos, the dripping period of a superfluid 4He liquid is discretized to a constant value specified by integers even if the inflow rate changes. We clarify that this robust discretization is the realization of a continuous-time crystal from the viewpoints of inflow rate phase diagram, temperature phase diagram, wall shape and dimensionality, and time-domain phonon excitation.
Ryuji Nomura, Tomoyuki Tani, and Yuki Aoki
Grant-in-Aid for Scientific Research(B) 2025.4.1～2028.3.31
One-Pass Synthesis of BTX from CO₂ Enabled by Precisely Controlled Catalysts
CO₂ utilization is essential for achieving carbon neutrality, and among potential target products, BTX (benzene, toluene, and xylene) are key basic chemicals in a post-fossil society. In this study, we build on previous collaborative research between the University of Tokyo, Hokkaido University, and Idemitsu Kosan Co., Ltd. We aim to precisely control the catalyst structure at the atomic level, enabling one-pass synthesis of BTX from CO₂. Through this approach, we seek to establish a catalyst process that is robust and scalable, suitable for industrial application, and capable of supporting a sustainable future without reliance on fossil resources.
Shohei Tada, Kotaro Takeyasu, Ryota Osuga, Kenta Iyoki, Yuichiro Kanematsu, and Idemitsu Kosan Co., Ltd.
NEDO Feasibility Study Program (2025~)