David M Carr oral presentation (OB1-Thu2-1-2)
3D TOF-SIMS Characterization of Natural Photonic Crystals in Glitterwing (Chalcopteryx rutilans) Dragonfly Wings
1 Physical Electronics, 18725 Lake Drive East, MN 55317 Chanhassen, United States
2 Departamento de Física - ICEx, UFMG, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
3 Centro de Microscopia - UFMG, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
4 Departamento de Morfologia - ICB, UFMG, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
5 Departamento de Zoologia - ICB, UFMG, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
The male Amazonian glitterwing (Chalcopteryx rutilans) dragonfly has transparent anterior wings and brightly colored iridescent posterior wings. The colors are important for dragonflies with regard to sexual recognition, mating, and territorial behavior. Valeriano  used electron microscopy and optical reflectance to analyze the internal microstructures of the wings to determine the source of the varying colors. SEM and TEM images revealed that the iridescent wings have multiple alternating layers with different electronic densities. The number and thickness of the layers varied across the wing which gave rise to variations in the local color. The colors span the visible spectrum with red, blue, and yellow/green regions on the wings. The experimental reflectance was calculated and fitted through the transfer matrix method for the structure obtained from the electron microscopy images. While electron microscopy can clearly measure the thickness and number of the layers, it is unable to characterize the chemistry of the different layers giving rise to these natural photonic crystals.
TOF-SIMS is a well-established technique for analyzing the elemental and molecular chemistry of surfaces. With the advent of cluster ion beams such as C60+ and large cluster Arn+, TOF-SIMS can now be used to probe the 3D structure and chemistry of a wide variety of organic and inorganic materials, both synthetic and naturally occurring. We will present results of 3D TOF-SIMS analyses for both transparent and colored wings to correlate with the electron microscopy and optical results to further the understanding of these natural photonic crystals.
 W.W.Valeriano, Masters dissertation, UFMG, 2016. Retrieved from http://www.fisica.ufmg.br/posgrad/Dissertacoes_Mestrado/decada2010/wescley-valeriano/WescleyWalisonValeriano-diss.pdf.