JAPAN NANONET BULLETIN - 2nd Issue - October 2, 2003

NANONET INTERVIEW

Toyoki KUNITAKE Vice President, The University of Kitakyushu Group Director Frontier Research System, The Institute of Physical and Chemical Research (RIKEN) 1958 Graduated from Department of Applied Chemistry, Faculty of Engineering, Kyushu University 1962 Doctorate Degree from Graduate School of Science, University of Pennsylvania 1962 Postdoctoral researcher, California Institute of Technology 1963 Associate Professor, Faculty of Engineering, Kyushu University 1974 Professor, Faculty of Engineering, Kyushu University 1992-1994 Dean, Faculty of Engineering, Kyushu University 1999 Professor, The University of Kitakyushu 1999 Medal with Purple Ribbon (National honor for outstanding scientists and artists) 2001 Japan Academy Prize Present Vice-president, The University of Kitakyushu Area Supervisor, “Organization and Function,” PRESTO, Japan Science and Technology Corporation Group Director, Spatio-Temporal Function Materials Research Group, Frontier Research System, RIKEN

Toyoki KUNITAKE, Vice President
The University of Kitakyushu
Group Director
Frontier Research System, The Institute of Physical and Chemical Research (RIKEN)

Using biomaterials to realize Spatio-Temporal Function through nanotechnology

The technology to prepare fine materials with nanometer-precision has become essential for many materials such as biological material, organic and inorganic compounds, metals and nanoparticles. By using this technology, Prof. Kunitake, as a group director, intends to develop completely new nanomaterials called Spatio-Temporal Function Materials.

For example, skin, bone, and cells make up the human body and constantly regenerated, meaning biomaterials combine the two features of 'spatial structure' and 'temporal element'. Saptio-Temporal Function Materials are unique artificial materials, which have the two features as biomaterials. They must be structured intricately and precisely, as biomaterials are. This can be realized through nanotechnology, in which atoms and molecules are processed.

The project consists of four research teams: Local Spatio-Temporal Functions, Dissipative-Hierarchy Structures, Exciton Engineering and Topochemical Design. Prof. Kunitake serves as a group director to conduct overall coordination of the research teams.

What are the targets of the four teams? The Local Spatio-Temporal Functions Lab engages in manipulation of self-assembled monolayers and proteins, and analysis of intermolecular forces. The Dissipative- Hierarchy Structures Lab works on the preparation of dynamic self- organized materials that do not require etching technique or oxide films in microchip processing. The Exciton Engineering Lab aims at controlling unstable excitons, which are electron-hole pairs created when atoms or molecules are irradiated by light. The Topochemical Design Lab strives to prepare materials with nano- precision, such as metal oxides and ceramic thin films, which have properties that are completely different from those of conventional ceramic materials.

Fig. 1 Large Image

The four essential areas of research require thorough study. Prof. Kunitake says, “I have chosen the four areas because they are expected to be the main pillars in the widespread field of spatio-temporal research. Each team is working with wide view points because we can’t predict what will surface as promising subjects.”

Prof. Kunitake also serves as the laboratory head of the Topochemical Design Lab. ‘Topo’ means ‘shape.’ He says, “I'd like to prepare novel nanomaterials by taking advantage of the shape of molecules.” By wrapping a molecule with a particular material, and then removing the molecule, the molecular template is processed. This molecular template enables us to select or pick out similar structured molecules from various molecules. The laboratory has already developed a technique to create capsules of nanometer level and has confirmed their hollow structures. Prof. Kunitake stressed that his goal was to more precisely design such shapes and that this was the most interesting part of the study.

This year, Spatio-Temporal Function Materials Research will reach the midway point of the 8-year plan. Over the next half, the results of each team must be shaped into the goal, the development of Spatio- Temporal Function Materials. The results will be seen in a few years. Prof. Kunitake says enthusiastically that “It is important to study and understand the dynamics of nanostructures for the future of material development. We need to know how nanostructures work and function together with other materials.”

Fig. 2 Large Image

Prof. Kunitake graduated from Kyushu University. He worked to prepare enzymatic models using polymer molecules in the 1960s, when he was in his late 20s. Enzymes react with particular molecules with high activity and selectivity. It is known that enzymes dissolved in human bodies assume spheres whose surfaces are compatible with water but whose inner volumes are not. The goal of his research was to place molecules at the right positions in the spheres. Otherwise, enzyme specificity would not appear. It was difficult for Prof. Kunitake to do so using artificial polymer molecules. He then turned to thin films in the late 1970s and succeeded in developing synthetic bilayer membranes with the property of self-assembly. Such membranes form automatically when dissolved in water. These materials have been used as carriers to deliver drugs, genes and DNA to their destinations. Prof. Kunitake's synthetic bilayer membrane marks the beginning of the organic thin film technology. For this achievement, he was awarded the Japan Academy Prize in 2000. The basic technology he developed has been one of the core of Spatio-Temporal Function Materials Research.

(Interviewer: Shin Chikushi)

Fig. 3 Large Image