LED technology: Butterflies got there first

African swallowtail butterflies, long admired for their "brighter–than–bright" wings, use "what was thought to be exclusively human advanced technology: high–efficiency photonic crystals like those of LEDs," wrote Larry O'Hanlon in a recent Discovery News story.

A paper on the findings, by Dr. Peter Vukusic and Ian Hooper of Exeter University in the U.K., appears in the current issue of the journal Science.

Man–made LEDs use electricity to create their bright light; butterflies do it with sunlight — and have been doing so for over 30 million years.

Butterflies grow photonic crystals (top — a magnified wing segment), which are made by man of silica, usually in neat arrays.

The butterfly crystals, once grown, are no longer alive but, rather, are like hair or fingernails.

Butterfly wings thus work as light–emitters long after a butterfly is dead.

The wings also contain micromirrors and microscopic holes, which act together with the crystalline structures to reflect light outward as well as change the wavelength of absorbed light and then reflect it, amplifying the emitted overall intensity in a given wavelength above that absorbed.

The function of the crystals in life seems to be for territorial signalling to other butterflies of the same species: they have receptors in their eyes for the same colors they flash.

I wonder when, in the near or distant future, a scientist will discover that somewhere in the animal or plant or even fungus kingdoms there are organisms with biologic lasers.

And what even more wondrous technologies we haven't even discovered yet, and can't begin to imagine, will be found to have been hiding in plain sight from us all these centuries and millenia among our feathered, furry and finny friends.