Stories tagged iridescence

Mar
06
2012

Iridescence is usually a vanity thing in nature; birds and butterflies, for instance, use it to attract mates. This is Golden Mole: The tiny structures that help streamline the mole and make it water-repellant also give it its iridescence.
Golden Mole: The tiny structures that help streamline the mole and make it water-repellant also give it its iridescence.Courtesy Killer18
the type of thing that would be completely lost on a blind mole...or is it? In the case of the golden mole, iridescence is very much a part of its appearance, but according to a new study about the structure of hair, this iridescence takes on a more functional role. The nano-sized structures on the flattened, paddle-shaped hairs not only give the moles a lovely sheen (for animals that can actually see them), but may also help to repel water and streamline the moles as they move through the sand. This is definitely a case of function over form.

Nov
02
2007

Nanotechnology sometimes borrows from nature.

Morpho butterfly: Pigments don’t cause these butterflies’ intense colors. Instead, super-small lattice-like structures on the wings reflect only certain wavelengths of light (or color). And the colors shift with your perspective. (Photo courtesy Lionoche, through Flickr)
Morpho butterfly: Pigments don’t cause these butterflies’ intense colors. Instead, super-small lattice-like structures on the wings reflect only certain wavelengths of light (or color). And the colors shift with your perspective. (Photo courtesy Lionoche, through Flickr)

Super-small, light-reflecting structures—instead of pigments—create a morpho butterfly's intense, iridescent wing color. Scientists are developing nanomaterials with similar properties.

Zoom in on a butterfly's wing
Zoom in on a butterfly's wing

If you used a special microscope to look at these butterfly wings, you’d see tiny scales made up of thin layers of transparent wing material with nanoscale gaps between them. Light waves bouncing off the bottom surfaces interfere with waves reflecting from the tops. Most light waves are cancelled and only certain wavelengths—or colors—bounce back to your eyes. The more light in the environment, the brighter the color.

Wing structures: These complicated structures on butterfly wings manipulate light to control the color that we see.
Wing structures: These complicated structures on butterfly wings manipulate light to control the color that we see.

How do transparent thin films create color?: Scientists haven't yet created materials that work exactly like the butterfly wings. But layers and layers of transparent, super-thin films--each with a different index of refraction--can be tuned so that they only reflect specific wavelengths of light (o
How do transparent thin films create color?: Scientists haven't yet created materials that work exactly like the butterfly wings. But layers and layers of transparent, super-thin films--each with a different index of refraction--can be tuned so that they only reflect specific wavelengths of light (o

Scientists are developing all sorts of products that, like the butterfly wings, use layers of transparent materials with nanoscale spacing between them to manipulate light and create color. With them, we can create computer and cell phone displays, fabrics and paints that change color, optical devices that improve telecommunications systems, and films that reflect much more light than glass mirrors. Can you imagine other uses?