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                        JAPAN NANONET BULLETIN
               -- 2nd Issue --       October 2, 2003
Nanotechnology Researchers Network Center of Japan
Ministry of Education, Culture, Sports, Science and Technology (MEXT)
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IN THIS ISSUE

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

  Young Researchers' Introduction:
    Shiyoshi YOKOYAMA, Senior Researcher, KANSAI Advanced Research 
Center, Communications Research Laboratory

  What's in the next issue?


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NANONET INTERVIEW

Using biomaterials to realize Spatio-Temporal Function through 
nanotechnology

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

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.

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."

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)

For more information, 
http://www.nanonet.go.jp/english/mailmag/2003/002a.html


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YOUNG RESEARCHERS' INTRODUCTION

Molecular architecture and engineering in nano- and submicro-
technology

  Shiyoshi YOKOYAMA, Senior Researcher, KANSAI Advanced Research
  Center, Communications Research Laboratory

The latest advances in nanotechnology have generated materials and 
devices with new physical characteristics and chemical functionalities 
for a wide variety of applications.  In particular, rapid advances in 
the performance of organic and polymeric materials in electronic and 
optoelectronic devices have been seen because of their flexible tuning 
of electronic structures.  Active efforts in this burgeoning field 
directly impact how we tailor novel materials in such areas as 
molecular electronics and molecular photonics, and how we integrate 
miniaturized systems such as molecular wires and assemblies even on a 
scale of sub-micrometers.  

Our research is focused on controlling chemistry in order to obtain 
the molecular assembled systems, and fabricating materials in the 
higher dimensions.  We have demonstrated molecularly assembled wires 
and clusters grown by molecule-molecule selective aggregation.  

Our findings suggest that careful placement of functional groups that 
can be used in directed non-covalent interactions will enable the 
rational design and construction of a wide range of supramolecular 
architectures with nanometer-scale precision.  The conjugated 
electronic nature of organic molecules often results in considerably 
complex aggregates in bulk.  This makes it difficult to scale up the 
molecular systems to the sub-micrometer scale for wide applications.  
We have shown that the dendritic macromolecule, called dendrimer, 
becomes a cavity that encapsulates pigments such as fluorescent dye 
and nonlinear optical dye.  

As a result, we get optically high-gain media, which perform amplified 
stimulated emission and laser emission.  Research is extending to an 
optical system that can be fine-tuned for mirrorless optical devices 
even in small-size device applications.

For more information,
http://www.nanonet.go.jp/english/mailmag/2003/002b.html


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The next issue of JAPAN NANONET BULLETIN will be delivered on October 
16. 

WHAT'S IN THE NEXT ISSUE?

  Nanonet Interview:
  Masuo AIZAWA, President, Tokyo Institute of Technology

  Young Researchers' Introduction:
  Shigenori FUJIKAWA, Special Postdoctoral Researcher, Topochemical 
Design Laboratory, Frontier Research System, The Institute of Physical 
and Chemical Research (RIKEN)


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