Mimicking structure of firefly abdomens created more efficient LEDs

WASHINGTON, Jan. 8 (UPI) -- Canadian and European scientists say they've taken a lesson from fireflies to make a light-emitting diode more than 1 1/2 times as efficient as the original.

Researchers from Belgium, France and Canada studied the internal structure of firefly lanterns, the organs on the bioluminescent insects' abdomens that light up to attract mates.

Writing in the journal Optics Express, they said they found an unexpected pattern of jagged scales that enhanced the lanterns' glow, and applied that knowledge to LED design to create an overlayer that mimicked the natural structure and increased light extraction by up to 55 percent.

"The most important aspect of this work is that it shows how much we can learn by carefully observing nature," Annick Bay, a doctoral student at the University of Namur in Belgium, said.

Bay studies natural photonic structures such as beetle scales and butterfly wings.

The unique surface geometry of some fireflies' abdomens helps minimize internal reflections, meaning more light escapes to reach the eyes of potential firefly suitors, the researchers said.

Human-made light-emitting devices like LEDs face the same internal reflection problems as fireflies' lanterns and Bay and her colleagues thought creating a surface cover mimicking the firefly abdomens could make LEDs brighter.

"What's nice about our technique is that it's an easy process and we don't have to create new LEDs," Bay said. "With a few more steps we can coat and laser pattern an existing LED."