The Structure Of The Beetle Color And Luster Mechanism Research

Colors are produced by one of two primary mechanisms, or by their combination:(i) pigmentary coloration and (ii) structural coloration. Structural colors are produced by the physical interactions between light and nanometre-scale variations, which have many excellent features over pigmentary coloration. Structural colors play an important role both in the living of animals and plants and in communications between animals. The study of structural colors in nature may bring inspirations for manufacturing photonic, memory and display materials. In this thesis, we study the structural origin of iridescence and sexual dichromatic luster in the elytra of beetle Goliathus cacicus. Furthermore, we study the color origin of the wings of mosquito and the elytra of beetle Sphingnotus mirabilis.This thesis consists of four chapters. In Chapter One, structural colors and their production mechanisms are briefly introduced. Structural color is of great significance for animals and plants. Bio-mimicry has also been briefly discussed in Chapter One.In Chapter Two, the experimental and theoretical methods for studying structural colors are introduced. We are interested in the optical characteristics of samples and thus reflection measurements are one of our main tasks. In this chapter, we introduce how to set up an angle-resolved spectrum analysis system for measuring reflection spectra. The system can measure specular reflection spectra, scattering spectra and polarization spectra covering the range of UV-VIS-IR, which is helpful for the investigation of structural colors in beetles and birds.In Chapter Three, we study the structural origin of iridescence and sexual dichromatic luster in the elytra of beetle Goliathus cacicus. The colors of the elytra stem from tubular scales densely covering the elytra. The optical characteristic of tubular scales has been little studied. Luster has also been little documented and studied in beetles. In this chapter, we find the structural origin by the comparison of measured spectra and numerical results. At last, we discuss the structural origin of difference in luster by measuring the scattering spectra.In Chapter Four, we study structural colors in wings of mosquito. Different zones of one wing possess various colors which originate from a thin film with a different thickness. Furthermore, we find the elytra of beetle Sphingnotus mirabilis are also covered with numerous scales which have a phase separation microstructure.