Emergent Bioinspired Soft Matter Research Team

Principal Investigator

PI Name Yasuhiro Ishida
Degree D.Eng.
Title Team Leader
Brief Resume
2001D.Eng., University of Tokyo
2001Assistant Professor, Graduate School of Frontier Sciences, University of Tokyo
2002Assistant Professor, Graduate School of Engineering, University of Tokyo
2007Lecturer, Graduate School of Engineering, University of Tokyo
2007Researcher, PRESTO, Japan Science and Technology Agency
2009Team Leader, Nanocomposite Soft Materials Engineering Team, RIKEN
2010Team Leader, Bioinspired Material Research Team, RIKEN
2013Team Leader, Emergent Bioinspired Soft Matter Research Team, Supramolecular Chemistry Division, RIKEN Center for Emergent Matter Science (-present)

Outline

Owing to intrinsic similarity to living organisms, such as lightweight, softness, and biocompatibility, soft materials have attracted increasing attention for biomedical applications, including artificial organs. However, in terms of structure, there is a significant difference between synthetic soft materials and living organisms; most synthetic soft materials are of isotropic structures, while living tissues are anisotropic. As seen in muscular, bone, and nerval textures, such anisotropic structures play critical roles for exhibiting their superb functions. By using external fields for orienting constituents, we have developed various anisotropic soft materials with highly oriented structure and unprecedented unique functions reminiscent of living organisms.

Research Fields

Chemistry, Materials Science

Keywords

Self-assembly
Biomimetics
Soft material
Stimuli-responsive material
Environmentally friendly material

Results

Synthetic hydrogel like cartilage, but with a simpler structure

– Potential as artificial cartilage and anti-vibration materials –

Electrostatic and magnetic repulsive forces are used in various places, as in maglev trains, vehicle suspensions or non-contact bearings etc.  However, design of polymer materials, such as rubbers and plastics, has focused overwhelmingly on attractive interactions for their reinforcement, while little attention has been given to the utility of internal repulsive forces.  Nevertheless, in nature, articular cartilage in animal joints utilizes an electrostatically repulsive force for insulating interfacial mechanical friction even under high compression.

We discovered that when nanosheets of unilamellar titanate, colloidally dispersed in an aqueous medium, are subjected to a strong magnetic field, they align cofacial to one another, where large and anisotropic electrostatic repulsion emerges between the nanosheets.  This magneto-induced temporal structural ordering can be fixed by transforming the dispersion into a hydrogel.  The anisotropic electrostatics thus embedded allows the hydrogel to show unprecedented mechanical properties, where the hydrogel easy deforms along a shear force applied parallel to the nanosheet plane but is highly resistive against a compressive force applied orthogonally.

The concept of embedding repulsive electrostatics in a composite material, inspired from articular cartilage, will open new possibilities for developing soft materials with unusual functions.

Hydrogel embedded with an anisotropic electrostatic repulsive force.

Members

Yasuhiro Ishida

Team Leader y-ishida[at]riken.jp R

Kuniyo Yamada

Expert Technician

Krishnachary Salikolimi

Postdoctoral Researcher

Xiang Wang

Postdoctoral Researcher

Koki Sano

Special Postdoctoral Researcher

Noriko Horimoto

Technical Staff I

Zhifang Sun

Visiting Scientist

Prathap Annamalai

Visiting Researcher

Yiyang Zhan

Visiting Researcher

Hayato Kanai

Junior Research Associate

Shuxu Wang

Junior Research Associate

Zhihao Li

Student Trainee

Jungho Lee

Student Trainee

Publications

  1. K. Sano, N. Igarashi, Y. Ebina, T. Sasaki, T. Hikima, T. Aida, and Y. Ishida

    A mechanically adaptive hydrogel with a reconfigurable network consisting entirely of inorganic nanosheets and water

    Nat. Commun. 11, 6026 (2020)
  2. K. Salikolimi, V. K. Praveen, A. A. Sudhakar, K. Yamada, N. N. Horimoto, and Y. Ishida

    Helical supramolecular polymers with rationally designed binding sites for chiral guest recognition

    Nat. Commun. 11, 2311 (2020)
  3. Y. S. Kim, M. Liu, Y. Ishida, Y. Ebina, M. Osada, T. Sasaki, T. Hikima, M. Takata, and T. Aida

    Thermoresponsive actuation enabled by permittivity switching in an electrostatically anisotropic hydrogel

    Nat. Mater. 14, 1002 (2015)
  4. C. Li, J. Cho, K. Yamada, D. Hashizume, F. Araoka, H. Takezoe, T. Aida, and Y. Ishida

    Macroscopic ordering of helical pores for arraying guest molecules noncentrosymmetrically

    Nat. Commun. 6, 8418 (2015)
  5. M. Liu, Y. Ishida, Y. Ebina, T. Sasaki, T. Hikima, M. Takata, and T. Aida

    An anisotropic hydrogel with electrostatic repulsion between cofacially aligned nanosheets

    Nature 517, 68 (2015)

Articles

お問い合わせ

#117-1 Frontier Material Research Laboratory, 2-1 Hirosawa, Wako, Saitama 351-0198 Japan

TEL:+81-(0)48-462-1111 (6351)

FAX:+81-(0)48-467-8092

E-mail:
y-ishida[at]riken.jp

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