Microstructure And Reflecting Optical Characteristics Of Several Typical Butterfly Scales

In recent years, numerous domestic and overseas research groups have devotedincreasing attention to butterfly study. They have made a lot of trials and researchesabout the dimension, the configuration, and the distribution of wing-scales, andbrought forward many special opinions of the origin of wing's color. Many overseasresearchers did many experiments and made a great progress in this field. There aretwo mechanisms to be used for butterflies to produce their colors. One is thechemical color, which originates from the chemical pigments. Different pigmentsappear different colors. The other is structural color, which is related with thesurface microstructure of the wing-scales. There is no any pigment, and is called"Schemochrome" sometimes.The actual styles of structural color are associated with the shape and theperiodic microstructure. The principle is to make the incident light to generatecertain optical effects and produce different colors, such as interference, diffractionand dispersion.This study is fulfilled without regarding the pigmentation condition and basedon some advanced methods. We have made some new exploitation and discover themicrostructure and Schemochrome about some familiar species of butterflies in thenortheast area of China. By using the optics microscope, we can observe the generalform and geometry dimension of the scales and their arrangements.By using the JEOL SEM (scanning electron microscope), the 2D scanning andmeasurement were made about the single scale surface. Then, with the help of JEMTEM (transmission electron microscope), the dimension and the structurecharacteristics of the cross section were got. Combining the SEM 2D data and theTEM data, the 3D optimized configurations were formed. By using thePro-Engineer—a 3D software, several 3D single scale models were described andthe 3D perceptibly effect was achieved.By using TU-1901 UV-VIS spectrometer, the reflectivity of three kinds of scalesamples at the spectrum range of 350nm-800nm were measured. The experimentresults were contrasted and the reflectivity charts were drawn. From the chart, it wasshown that the reflectivity of the blue region sample of the green-band-pappilobutterfly was less than that of any other samples at any wavelength.Based on the dispersion and reflection theories, the optics effects wereanalyzed, and an important conclusion was drawn. The blue color on thegreen-band-pappilo butterfly wings was structural-color and generated by themicrostructure of its scales, which was the result of the dispersion effect producedby the repeated microstructure.This study put forward a basis method and model for the future study on theoptics effect of biological microstructure.