06 April 2009

Bird plumage color produced by nanostructures

Most colors in nature—from the color of our skin to the green of trees—are produced by pigments. But the bright blue feathers found in many birds, such as Bluebirds and Blue Jays, are instead produced by nanostructures. Under an electron microscope, these structures look like sponges with air bubbles.

Now an interdisciplinary team of Yale engineers, physicists and evolutionary biologists has taken a step toward uncovering how these structures form. They compared the nanostructures to examples of materials undergoing phase separation, in which mixtures of different substances become unstable and separate from one another, such as the carbon-dioxide bubbles that form when the top is popped off a bubbly drink. They found that the color-producing structures in feathers appear to self-assemble in much the same manner. Bubbles of water form in a protein-rich soup inside the living cell and are replaced with air as the feather grows...

"We are now mimicking this approach to make a new generation of optical materials in the lab."

1 comment: