Hideyuki Ootsuka

Mechano-multifunctional Polymeric Materials Based on Dynamic Covalent Chemistry

Grant No.：JPMJCR1991

Research Director

Hideyuki Ootsuka

Collaborator

Hiroshi Ito

Vice President Yamagata University

Outline

Functional materials triggered by macroscopic mechanical stimulation such as compression, stretching, shearing, bending, impact, and friction are called “mechanofunctional materials”. In this project, innovative mechano-multifunctional polymeric materials, which show more than one mechano-functionality will be prepared. The materials design will be based on “dynamic covalent chemistry” which utilizes the covalent bonds under equilibrium. Furthermore, mechanism of the multi-mechanofunctional materials will be clarified by multi-scale dynamic analyses to obtain insight into a guiding principle of the materials design.

Takamasa Sakai

Elucidation of robust-toughening mechanism of gels and development of artificial tendon and ligament

Grant No.：JPMJCR1992

Research Director

Takamasa Sakai

Collaborator

Kotaro Satoh	Professor School of Materials and Chemical Technology Institute of Science Tokyo
Yuichi Masubuchi	Professor Graduate School of Engineering Nagoya University
Koichi Mayumi	Associate Professor The Institute for Solid State Physics The University of Tokyo

Outline

For a practical application of hydrogels to artificial tendons and ligaments, we develop innovative biocompatible hydrogels that constantly exhibit an excellent mechanical response (mechanical robustness) even in harsh environments with repeating mechanical stress. To achieve mechanical robustness, we will introduce a novel toughening mechanism, i.e. control over dynamic and static crystallizations. Throughout synthesis, experiment, and simulation, we will elucidate the robust-toughening mechanism based on dynamic and static crystallization. Finally, we will develop prototypes of artificial tendon and ligament, and examine the functionality through the animal experiments.

Hiroshi Jinnai

Elucidation of adhesion/fracture mechanism of soft/hard interface by atomic resolution electron microscopy

Grant No.：JPMJCR1993

Research Director

Hiroshi Jinnai

Collaborator

Kazutomo Suenaga	Professor Institute of Scientific and Industrial Research The University of Osaka
Teruyasu Mizoguchi	Professor Institute of Industrial Science The University of Tokyo
Kaname Yoshida	Senior Researcher Nanostructures Research Laboratory Japan Fine Ceramics Center

Outline

Combining organic and inorganic materials is an effective method for realizing lightweight and high-strength materials. Such a composite material has an interface (called a heterogeneous interface) where different materials come into contact, and plays an important role in the function of the material. In this study, we used the most advanced electron microscopy and theoretical calculations to precisely identify the arrangement of atoms and molecules at the interface. Furthermore, we will clarify the fundamental principle of adhesion/fracture mechanism at the heterogeneous interface by applying the above atomic scale knowledge to the macroscopic delamination phenomena, called the anchor effect.

Nobuhiro Tsuji

Advanced structural metals showing both high strength and large ductility by controling nucleation of different deformation modes

Grant No.：JPMJCR1994

Research Director

Nobuhiro Tsuji

Collaborator

Tomotsugu Simokawa	Professor Institute of Science and Engineering Kanazawa University
Mayu Muramatsu	Associate Professor Faculty of Science and Technology Keio University
Mitsuhiro Murayama	Professor Institute for Materials Chemistry and Engineering Kyushu University

Outline

We firstly clarify the mechanism for the nucleation of various deformation modes from grain boundaries and interfaces in the metallic materials having highly controlled nano-/micro-structures. Then, the mechanism for the regeneration of strain-hardening ability by the nucleation of different deformation modes is fundamentally studied. Based on the obtained results, we try to realize advanced structural metals having both high strength and large ductility, through designing and processing the nano-/micro-structures of materials in which different deformation modes can be sequentially activated. Using state-of-the-art methods in both experiments and calculations, deformation mechanism in nano—scales is correlated with macroscopic deformation behaviors.

Hiroyuki Toda

Tomography for bridging nano and macro: semi-spontaneous interfacial debonding

Grant No.：JPMJCR1995

Research Director

Hiroyuki Toda

Collaborator

Taisuke Sasaki	Group Leader Research Center for Magnetic and Spintronic Materials National Institute for Materials Science
Shigeru Hamada	Professor Graduate School of Engineering Kyushu University
Kyosuke Hirayama	Associate professor Faculty of Engineering and Design Kagawa University
Kenji Matsuda	Professor Academic Assembly University of Toyama
Masatake Yamaguchi	Research Director Center for Computational Science & e-Systems Japan Atomic Energy Agency
Ikumu Watanabe	Principal Researcher Center for Basic Research on Materials National Institute for Materials Science

Outline

In this project, we revisit the ductile fracture via interfacial debonding of particles by employing the advanced micro- and nano-tomography techniques for bridging nano and macro, and also by combining it with the nanoscopic image-based computational physics and the macroscopic mechanical-engineering approach. We will thereby elucidate the debonding mechanism of incoherent interface and also physically clarify its dominant factors. We will provide academic approaches to bridge nano and macro by utilizing the fact that nanoscopic dislocations are identical to macroscopic strain.

Hidehiro Yoshida

Strong field nanodynamics at grain boundaries and interfaces in ceramics

Grant No.：JPMJCR1996

Research Director

Hidehiro Yoshida

Collaborator

Koji Morita	Group Leader Research Center for Electronic and Optical Materials National Institute for Materials Science (NIMS)
Takahisa Yamamoto	Professor Graduate School of Engineering Nagoya University

Outline

Ceramic materials under strong electric fields have been found to exhibit unique mechanical responses such as low-temperature and high-speed superplastic deformation. Behind these phenomena, a new physics termed strong field nanodynamics is hidden; that is, an excitation of kinetics in the nanoscale regions such as grain boundaries and interfaces. In this research project, we will build a discipline of strong electric field nanodynamics and aim to obtain theoretical guidelines for development of new macromechanical responses such as large ductility and strong-field healing in ceramics.