JFS Biomimicry Interview Series: No.2 Second interviewee:Kiichi Takemoto

JFS Newsletter No.27 (November 2004)
Technologies Learned from Living Things: Concepts and Examples - Front Line Reports

Plastics and most other synthetic macro-molecules made from petrochemicals do not decompose naturally, and this makes their disposal and treatment a matter of serious concern. In this context, attention is being increasingly paid to studies of natural cycles of synthesis and decomposition in an effort to learn from living things.

This month's interview is with Professor Kiichi Takemoto, Professor Emeritus of Osaka University, who catapulted into the limelight by pioneering the new field of material biology in 1993. This field of study concerns itself with the development of new materials that mimic those made by living things. We asked him about the harmless and highly functional new materials that have been inspired by living organisms.

Q: How did you come up with the idea of learning from living things?

It came to me while reflecting on synthetic chemistry. My expertise is in high molecule chemistry. Rubber, plastic, fabrics and adhesives made with petrochemical technology all have high-molecule structures, and none of them decompose naturally. The synthetic processes developed by humans are all one-way and do not take decomposition into account, so they have a heavy impact on the environment. People are now seriously troubled by how to dispose of waste materials.

On the other hand, in the biological world, the synthetic process continues all the way down to decomposition. Excellent material cycles can be observed in nature. Thus, I think of this field of study as "material biology - discovering new materials by learning from living creatures." In this field, we study high-molecule materials created in the bodies of living things, that is, how these materials function and also how to identify useful materials The challenge for the future is how to establish an ideal resource cycle.

Q: Can you give some concrete examples of case studies in material biology?

One extremely interesting example is how abalone shells attach themselves to surfaces An abalone stuck to the side of a glass water tank cannot be pulled away even when a strong force is exerted, but it can be easily removed by moving it along the surface of the glass and slipping it off. This example illustrates the way living things can perform two very antithetical functions such as adhesion and separation, quite naturally and employing the same substance.

In 1987, Dr. J. H. Waite of the University of California found that the abalone's adhesive abilities arise from the physical nature of protein on of the surface of its muscle which involves an idiosyncratic amino acid sequence. The adhesives that humans have developed so far use chemical reactions in order to bond, and usually adhesion and separation are achieved using totally different substances. From the point of view of material recycling, we could reap great benefits if we could develop reversible adhesives based on what we have learned from the abalone.

Ants provide another example. Ants make solid nests using only their saliva and soil, rather than using materials similar to metal or ceramics. Surprisingly, however, dynamite is required to destroy some anthills. Anthills also maintain almost constant temperature and humidity. It would be very interesting if we could apply this to building wine cellars or in the housing industry. Living organisms are a gold mine of ideas.

Q: These examples are very interesting not only to specialists but to ordinary people like us, wouldn't you say?

Yes, I would. When I talk about these clever abilities and functions of living organisms especially to children, their eyes pop open and they say, "Wow!" In the summer of 2002, I gave a lecture on the adhesive properties of abalone to fourth through seventh graders and got a great response. School teachers said to me, "We can't take time to conduct experiments for science class because we have to prepare for the high school entrance examinations. However, the children listened to so eagerly to you that now they will never forget how interesting the natural sciences can be."

When I conduct experiments to illustrate the adhesion and separation power of abalone, the children who join in get all excited when they realize how wonderful living things are. The wisdom of living organisms can bring out the sensitivity in children. I would very much like to see this kind of thing introduced into the school curriculum.

Q: Do you have any message for scientists?

I believe we have only explored a small percentage of potential topics in the field of chemistry. More than 90 percent of the potential remain untapped. Studying material biology is one way to push back this frontier. Living things have evolved over an immense period of time - four billion years - and the material and functional concepts being realized by living things hold out unlimited possibilities. Progress is ongoing in the biotechnology industry, and we should be able to achieve more breakthroughs by learning from living things with an open mind.

Normally, acetone, benzene, and alcohol are used as solvents in chemical reactions, but all of these are toxic and flammable. By contrast, living things react using air and water, normal components of everyday life. As we can see from the examples of abalones and anthills, living things create highly functional materials out of completely harmless substances. We could try switching to water solvents as much as possible, as a way of achieving a turnaround in chemistry. This could be more economical than current practice and may become the key to solving many of the environmental problems we are facing right now.

After the Interview--What JFS Learned

"Material biology, the academic study of learning from biomaterials by identifying useful substances and functions" has the following significance from the point of view of sustainability.
- Establishing a material cycle in society that is based on the way materials are synthesized, circulated and decomposed in nature.
- Developing highly functional and harmless materials by studying the wisdom of living things evolved over a long period of time.
- Teaching children the fascinating aspects of living things and nurturing their sensibilities.

Some high potential future developments are:
- Studying living things from the viewpoint of sustainability and of potential application in industry.
- Providing environmental education for children.

(Interviewer: Keiko Hoshino)

*This interview series is supported by the Hitachi Environmental Foundation.