Toward a Material Civilization Nurtured by Water—Nanotechnology Inspired by Biomineralization

Hiroaki Imai (Professor, Department of Applied Chemistry)

The use of fire must have been revolutionary for ancient people. Fire provided warmth, cooked food, and was used to create pottery, glass, and eventually develop a material civilization centered on ceramics and iron. Our modern affluent lifestyle is supported by a wide variety of materials produced using the energy of fire. On the other hand, we must not forget that the vast amounts of energy and waste used to achieve this affluence are placing a burden on the environment.

Living organisms create a variety of exquisite substances in water at room temperature and atmospheric pressure, using them to form their own bodies. While soft organic matter is the main component, these also include robust inorganic substances (= biominerals) such as shells and bones. In other words, organisms produce useful materials not with the power of fire, but with the power of water, without burdening the environment.

These biominerals are remarkable materials that combine both hardness and flexibility. It has become clear that their secret lies in a hierarchical structure built by regularly stacking tiny, nano-sized blocks (Fig. 1). In our laboratory, we are investigating the mechanisms by which such biominerals are formed and conducting research to create various functional materials in water at near-room temperatures.

In the course of this research, we have found that organic matter dissolved in water supports the growth of inorganic crystals, spontaneously creating complex and exquisite structures. It is expected that microstructures created through nanotechnology inspired by these biological methods will demonstrate superior functions in the environmental and energy fields in the future. While human civilization to date has been built by fire, I have a feeling that a civilization nurtured by water is on the horizon.