Fireflies bring us brighter LEDs

Fireflies ... they’ve allowed us to image the bloodstream and they’ve inspired the creation of a light that could run on waste. Now, they’ve helped an international team of scientists get over 50 percent more light out of existing LED bulbs. The secret lies in the insects’ scales.

More specifically, the secret lies in the scales of the Photuris firefly.

In all types of fireflies, their bioluminescence is emitted through the cuticle of their exoskeleton. In most cases, the cuticle reflects some of that light back inwards, diminishing the total amount of light given off – a similar problem occurs with the outer coatings of LED bulbs.

It was discovered that in the Photuris genus, however, scales in the cuticle possessed optical qualities that boosted the amount of light that could get through. These qualities were concentrated along the jagged edges of the roof-shingle-like scales.

In order to test if the same principle could work for LEDs, a researcher at Canada’s University of Sherbrooke deposited a light-sensitive material on a standard gallium nitride LED bulb. He then used a laser to etch a profile into that coating, similar to that of the edges of the firefly scales. As a result, the bulb was able to emit approximately 55 percent more light.

“The most important aspect of this work is that it shows how much we can learn by carefully observing nature,” said Annick Bay, a Ph.D. student at the University of Namur in Belgium, which took part in the study. The European Synchrotron Research Facility in France and Belgium’s Université Catholique de Louvain were also involved in the research.

Source: The Optical Society