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Bright Silver Brilliancy from Irregular Microstructures in Butterfly Curetis acuta Moore
Author(s) -
Liu Xianghui,
Wang Dantong,
Yang Zhiwei,
Zhou Han,
Zhao Qibin,
Fan Tongxiang
Publication year - 2019
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201900687
Subject(s) - reflection (computer programming) , broadband , materials science , optics , viewing angle , total internal reflection , light reflection , azimuth , diffraction , property (philosophy) , butterfly , structural coloration , optoelectronics , physics , computer science , biology , ecology , philosophy , epistemology , photonic crystal , liquid crystal display , programming language
Structural whiteness in nature is one of the useful optical phenomena contributed by refined microstructures and serves important biological functions. However, whiteness residing in wings, antennae, and bodies of butterflies often draws less attention, with undetected physical mechanisms and applications. Here, it is discovered that bright silver scales on the ventral side of butterfly Curetis acuta Moore have enhanced broadband reflection with particular angle dependency, which is dominated by the irregularity of scales. The broadband reflection is the result of color mixing effect caused by laminated scales with irregular layer space and thickness. The special angle dependency suggests that the reflection intensity changes with azimuth angles but remains unvaried at different viewing angles along given direction. This is the consequence of diffraction caused by ridges and irregular holes on the scales, which generates the shining effect and extends the viewing angle of broadband reflection. The characteristic reflection property is speculated to be used for intraspecific communication. Furthermore, it is found that the broadband reflection property of the silver scales is helpful to lower the body temperature under direct sunshine. These findings for light and thermo controlling would offer a potential strategy to design bioinspired advanced materials for low‐energy, reflectance‐based applications.