Content of research

Conventionally, elastomers have widely been used as soft materials, but in situations where they are used as contact points with living organisms or as their substitutes, hydrophobicity is a critically important factor. Since hydrous materials strongly reflect the physical properties of water, they exhibit physical properties that are very similar to biological tissues. For example, heat transfer and electromagnetic wave absorption properties of hydrous materials are similar to those of living tissues, and their surface friction is as low as that of body tissues. Although gel is the most common hydrophilic soft material, its mechanical strength has been low and its application has thus been limited. We have succeeded in developing a highly strong double network (DN) gel that does not break, even when a truck drives over it, despite 90% water content. This has greatly expanded the possibilities of gel applications. While working to examine the toughness of DN gels, we have discovered the “sacrificial bonding principle,” arriving at the concept of strengthening various materials. In recent years, we have been developing various other types of strong gels besides DN gels.

Potential for social implementation

• ・Biological phantoms (organs, muscle-like properties)
• ・Surgical practice equipment
• ・Dummy doll for injury investigation
• ・Robot exterior
• ・Artificial cartilage, artificial blood vessels

Appealing points to industry and local governments

In short, gel is “water with a shape.” We aim to give it the toughness of rubber so that it can acquire expected functions. Naturally, it is also possible to add functions to the polymer components, so we will be able to prepare polymer materials depending on the purpose, such as gels of which the color changes when deformed and gels that allow us to visualize internal damage.