2004 Fiscal Year Final Research Report Summary
NANO-SIZED PERIODIC STRUCTURES IN CUTICULE OF INSECTS AND THEIR OPTICAL FUNCTIONS
| Project/Area Number |
15310079
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanostructural science
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| Research Institution | KUMAMOTO NATIONAL COLLEGE OF TECHNOLOGY |
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Principal Investigator |
MATSUDA Toyonori KUMAMOTO NATIONAL COLLEGE OF TECHNOLOGY, DEPT.OF INFORMATION & COMMUNICATION ENGINEERING, PROFESSOR, 情報通信工学科, 教授 (00157322)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Hideo NATIONAL INSTITUTE OF AIST, CYBER ASSIST RESEARCH CENTER, READER, サイバーアシス研究センター, 主任研究員 (40356481)
NISHIYAMA Eiji KUMAMOTO NATIONAL COLLEGE OF THECHNOLOGY, DEPT.OF INFORMATION & COMMUNICATION ENGINEERING, ASSOCIATE PROFESSOR, 情報通信工学科, 助教授 (00237752)
NAKAMURA Takashi KUSHIRO NATIONAL COLLEGE OF TECHNOLOGY, DEPT.OF ELECTRONICS ENGINEERING, PROFESSOR, 釧路工業高等専門学校・電子工学科, 教授 (40198213)
KAWANO Mitsunori KUMAMOTO NATIONAL COLLEGE OF TECHNOLOGY, DEPT.OF INFORMATION & COMMUNICATION ENGINEERING, ASSOCIATE PROFESSOR, 情報通信工学科, 助教授 (20305006)
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| Project Period (FY) |
2003 – 2004
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| Keywords | photonic crystal / insect / periodic structure / diffraction / microscopic spectrometer / structural color / polarization / simulation |
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| Research Abstract |
The aim of this project is to investigate optical functions of nano-sized structure that are formed on cuticles of certain insects. We focus our attention on periodic structures in the fine architecture on the cuticles and propose that the periodic structures are dominant to produce their optical functions. We deal with wing scales and ommateal corneas of two species of butterflies, male Morpho from South America and male Lycaenidae from Japan. In the term of project, we have carried on the following studies.
(A)We have observed scales of the butterflies by using a scanning electron microscope to investigate microscopic architectures of structurally colored wings. As a result, we found that the wing scales are regarded as periodic structures that consist of lamella and ridge. We next observed that the front surface of ommateal corneas of the butterflies is covered with minute nipples, which is much smaller than a wavelength of visible right and arranged in hexagonal array. It should be noted that the corneas could be considered as two-dimensional periodic structures of the nipples array.
(B)We have measured the spectral reflectance of wing scales by a microscopic spectrometer whose spot size is about 100 micrometer in diameter. The experimental results show that each scale exhibits brilliant blue or green. Optical functions of the corneal protuberance array might be to reduce the reflection of visible light from the front surface of cornea [C.G.Bernhard, Endeavour, 26, 79-84 (1967)].
(C)We have developed a numerical algorithm for analyzing optical functions associated with periodic structures in wing scales or ommateal corneas. The algorithm, which is based on the Yasuura method, leads us to solve a huge-sized least squares problem. We evaluate reflectance and transmittance of the periodic structure models in cuticles of insects over the visible region from computer simulation.
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