Investigation On Color Variation Of Morpho Butterfly And Fabrication Of Butterfly Scale-like Structures

Morpho butterfly wings show brilliant blue color, which is a typical structural colorin nature. The research on mechanisms of its structural color and biomimetic synthetic hasalways been the research front and hot topic internationally. In this thesis, the colorvariation of Morpho didius butterfly wings in different environmental media wasextraordinarily investigated, and experiment on fabrication of Morpho butterfly wingscale-like structures was performed. The main content and inclusion includes:When liquids such as methanol, ethanol and isopropanol with different refractiveindexes dropped onto the scales of Morpho didius butterfly, the reflectance of wingswould decrease. The main peaks of reflectance shifted to the right and the scales turned tobe yellow-green. After the liquids volatilized completely, the scales reverted to the originalblue color. The typical micro/nanostructures of Morpho butterfly wing scales weremodeled, and the reflectance variation in the course of dropping liquids was simulated.Furthermore, the principal component analysis(PCA) method was employed to analyze theexperimental and simulation reflectance data, extract principal components and reducedimensions. As a result, the curves mapping the reflectance variation were clearly shownin the coordinate system consisting of three principal components. The typical colorvariation of scales during the dropping process could be monitored, and different kinds ofliquids could be obviously distinguished according to the distributed regions of mappingpoints. Besides, the reflectance of two kinds of Morpho butterfly with several differentincident angles was measured separately. The results suggested the reflectance woulddecrease when the incident angle increased, so would the brightness of butterfly. When theincident angle was below a certain degree, the wavelength corresponding to the main peakof reflectance nearly stayed the same and the butterfly always showed blue. As theincident angle continued increasing, the main peak of reflectance decreased and shifted tothe left. At the same time, the color of the butterfly wings started to change. After theincident angle increased to a high degree, the wings would tend to be purple.Furthermore, the fabrication process based on sol-gel and magnetron sputteringtechnique had been carried out in sequence, which using Morpho rhetenor butterfly wingsas biotemplates and calcination molding method subsequently. Several oxides withbutterfly scale-like structures was fabricated finally and both the merit and demerit of twoprocess was compared. The soaking time of butterfly wings during sol-gel process wasregulated and the optimal soaking time was carefully investigated, by observing andmeasuring the micro/nanostructures and the composition of the different replica. On theother hand, as the products of the experiment based on magnetron sputtering technique, the ridge-rib like structures of Al2O3replica appeared to be seriously damaged and curly insome parts. To the contrary, the ridge-rib like structure of Al2O3replica was successfullypersisted and regularly arranged.This thesis helps us have a deep understanding of the color variation mechanism ofMorpho butterfly, as well as the fabrication and potential application of butterfly scale-likestructures. And it is helpful to the design, manufacture and applications of the bionicmicro/nanostructures/devices for environmental detection.