Development of Highly Light-Sensitive Film Systems for Micro-ReliefFormation and Their Applications
Takahiro Seki, Professor, Department of Applied Chemistry, Graduate School of Engineering,
Nagoya University
1. Introduction

0200 [ nm ]Recently a method has been found for forming relief structures byexposing polymer films containing azobenzene molecules to patternedlaser light, causing the material to migrate laterally. Our groupdeveloped a system capable of rapidly inducing mass migration within
seconds by exposing a flexible liquid crystal polymer to light. In order
to increase our understanding of this mass migration phenomenon andto contribute to micromachine technology, we studied the feasibility ofusing this system as a conveyor for other materials.

05510102. Development of Novel Polymers

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By introducing oligo(ethylene oxide) into the polymer as acopolymer, we developed an azobenzene polymer in which massmigration is induced with high sensitivity. Using this polymer, wefound that relief formations can be preserved, even at temperatures of
250 degrees celsius, by cross-linking the hydroxyl end group of theethylene oxide. We learned it is possible to overcome properties thatrun counter to highly sensitive light-induced migration and thepreservation of stable formations. Fig. 1 is an image taken through anatomic force microscope of a relief formed with a grid-shaped mask.

Fig. 1 An example AFM image of a relief formed bylight-induced mass migration

3. Photo-Conveyance of Functional Materials
Using this phenomenon of migration in film materials, we studied
the inducement of migration in other functional materials (Fig. 2).
This study showed us that migration is possible in dyes, conjugatedpolymers, and particles on the order of nanometers. This knowledge is
expected to become a new elemental technology for micromachines.

Fig. 2 A conceptual drawing showing patterning by
conveyance of functional materials using
light-induced migration

Electrochemical Immobilization of Engineered Protein for micro TAS
Tetsuya Haruyama, Professor, Department of Biological Functions and Engineering,
Kyushu Institute of Technology
1. Introduction
Proteins like enzymes and antibodies have specific affinities,
catalytic activity, and other superior functions. Devices that make useof these functions include bioreactors and biosensors achieved throughimmobilized enzymes and immunosensors achieved throughimmobilized antibodies. We have seen many attempts to develop
devices by reducing the size of these bioreactors and biosensors andemploying them as micro total analysis systems( µTAS) for applicationsin health care or food inspection. However, various restrictions make it
difficult to immobilize functional proteins on a miniaturized site. In thisstudy, we controlled the molecular orientation of immobilized protein
and attempted to develop an electrochemical immobilization method forreversibly immobilizing protein.

Protein targetedfor immobilization

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M2+NN

Electrochemicalreduction

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N

N

Protein targetedfor immobilization

EC-tag

2. Genetical Insertion of EC-tags and Electrochemical Immobilization of Proteins

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A principle of immobilization is to genetically add an EC-tag sequence(an amino acid sequence to become a divalent metal-ion coordinationsite) into the amino acid sequence of an immobilized protein and toconfigure divalent metal ions in this EC-tag site. We discovered a methodof immobilization in which the coordinated metal ions are restored fromtwo valences to zero by applying a reduction potential to the protein inthis state at an electrode surface. At this time, the protein is immobilizedon the surface of the electrode (Fig. 1). Protein immobilization performed
according to the above process is stable even after ceasing the potential
application and can be separated through a counterreaction.
Fig. 2 shows an atomic force microscope photo of an experimentusing this method to immobilize a model protein on the end of acantilever. In this example, the applied potential is focused on the radical
end through an edge effect to achieve protein immobilization only aroundthe end of the cantilever. This suggests the possibility of orientational
immobilization of monomolecular proteins using the extreme radical end
solid phase. Further, this method of immobilization can be used
universally for many proteins by genetically inserting an EC-tag in theamino acid sequence of the protein. The potential for designing molecularorientation using this method has engendered great promise for its
applications.

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Patent application No. 2003-069924

Fig. 1 Hypothetical scheme of EC tag-protein immobilization

AccV Probe Mag WD

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Fig. 2 SEM photograph of protein immobilized on
the end of a cantilever by an EC-tag2