Full-model Finite-element Analysis for Structural Color of Tarsiger cyanurus's Feather Barbs

Tsuyoshi Ueta^1*, Garuda Fujii² and Gen Morimoto³

¹Division of Physics, Department of Natural Science, The Jikei University School of Medicine, 8-3-1 Kokuryo-cho, Chofu, Tokyo 182-8570, Japan
²Institute of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano-city, Nagano 380-8553, Japan
³Yamashina Institute for Ornithology, 115 Konoyama Abiko, Chiba 270-1145, Japan
^*E-mail address: tsuyoshi_ueta@jikei.ac.jp

(Received June 1, 2020; Accepted September 4, 2020)

Abstract. This paper presents full modeling of the cross-section of a blue feather barb of Tarsiger cyanurus and computed optical properties of the barb by means of finite element simulations. Cross-sectional models of the blue barbs are created based on SEM and TEM observations and are characterized on the basis of the radial sizes and the arrangements of air-pores. Large-scale finite element method is employed in order to investigate reflective properties of a blue feather barb. Measured and computed results show good agreement in the visible wavelength range, when we take into account optical absorption of keratin.

Keywords: Tarsiger cyanurus, Finite Element Method, Structural Color, Reflection Spectrum, Absorption