Download
1 / 17
200 likes | 520 Views
شگفتی های نانو در طبیعت. محمد ابراهیم بحرالعلوم بخش مهندسی مواد دانشکده مهندسی دانشگاه شیراز. به نام آفریدگار زیبائی ها. Butterfly wings come in a variety of colours and patterns. Different types of colour. Chemical colour Physical (Structural) colour. Iridescence in Nature.
E N D
شگفتی های نانو در طبیعت محمد ابراهیم بحرالعلوم بخش مهندسی مواد دانشکده مهندسی دانشگاه شیراز
Different types of colour • Chemical colour • Physical (Structural) colour
Iridescence in Nature Constructive interference produces physical colours
Colors of a butterfly's wings The underside of a butterfly wings Chemical colour The topside of a butterfly wings Physical (Stuctural) colour
Wing structure and microstructure of a butterfly wing scale Light microscopic images ×200 ×1000 ×50 Electron microscopic images ×5000
Constructive interference amplifies the colors of a butterfly's wings
Electron microscopic images of a scale of a butterfly wing showing its nanostructure SEM micrograph showing a longitudinal view of ascale. Scale bar, 1 μm. TEM micrograph showing a cross section through the scale. Scale bar, 2.5 μm.
Blue light has a wavelength range from 400 to 480 nm. The slits in the scales of a butterfly wing are 200 nm apart. Because the distance between slits corresponds to half of the wavelength of blue light, this is the wavelength that undergoes constructive interference.
The colouration of butterfly wings serves many purposes • Camouflage, in which the color of the animal helps it blend into the environment, hiding the insect. • Attracting and finding mates, who look for certain colours and patterns.
The colouration of butterfly wings serves many purposes • Deceiving predators into thinking they're bigger than they really are. Some wings make the butterfly look like the face of a larger animal (like an owl), scaring away some predators. • Soaking up heat: dark-colored scales soak up heat very well. Butterflies are cold-blooded. When they get too cold, they warm themselves in the sun.
Nanostructures on black butterfly wings help them to collect sunlight
Butterfly wings may rank among the most delicate nanostructures in nature. They have given researchers powerful inspiration for new solar cell technology.
Nanostructure which gives hydrophobic properties
The iridescent colour of a peacock originates in the fine side branches of the feathers. The actual colour depends on the exact position of the spot on the branch and on the angle of the incident light.
