Making functional materials from soft materials:Hotta's Group

Department of Mechanical Engineering, Keio University

The Hotta Lab is researching the possibilities of soft materials. Most soft materials utilize polymers, which are long molecules. By changing the molecular structure of polymers in various ways, and adjusting it carefully, its possible to change many of their properties. This can create hard materials like plastics, or soft, elastic materials like rubber elastomers, or gels, which contain a lot of solvent such as water and are very soft. Some polymer compounds are even harder than metals or ceramics.

Q.To give a very simple example, if you think of spaghetti, long molecules are very much like spaghetti. Although in molecular terms, they also have many differences from spaghetti, long molecules can get tangled up, and dry out and stick together, and when this happens, you get something rubbery. Also, for example, before you boil spaghetti, its hard and rigid - the sort of thing that would hurt if someone threw it at you. Some long and hard molecules are like that.

Its also possible to create lots of micro-holes in the molecular structure of a polymer, to make a lightweight material. This can help with environmental and energy issues. Also, once a synthesis method is established, polymers can be mass-produced at low cost. So theyre also attractive materials in terms of cost. The Hotta Lab is focusing on creating useful materials, by adding functional properties to promising materials of this type.

Q.For example, some materials can form structures within themselves, or repair themselves, so theyre actually self-repairing materials. Ordinarily, if you cut a material, it stays cut, but some materials can return to their original form if you cut them and put the pieces back together.

The Hotta Lab is also studying gel materials, which resemble the human body. The researchers are collaborating with physicians to develop medical materials that are friendly to the body. The Lab is working on a variety of materials development projects, and in the process, the researchers find mysterious structures that give rise to delicate polymers.

Q.What I always find interesting is that because these materials are polymers, theyre much more complicated than ordinary materials such as metals, although ordinary materials may also have interesting properties. For example, polymers usually dont have the properties you predict. They may only have 5% of the predicted properties, and thats also interesting. For example, I think everyones touched slime when they were a kid, and thought it felt weird, or been surprised how high a super-ball can bounce. But those sorts of things happen every day in our lab, and we try to explain why they happen. And we aim to utilize what weve discovered, to create new functions. This leads to all sorts of projects, and our hope is that these can be used for practical purposes. I think this is where the appeal of our research lies.

Category:

Science & Technology

Tags:

• ko
• hottaLab
• Englsh