We spend a lot of time in labs and workshops, trying to make our technologies more efficient and intuitive. This is unfortunate because Mother Nature is the most prolific engineer in the universe, and just a few hours in her outdoor classrooms often reveals simple solutions to our most vexing problems. When we apply these design solutions, it’s called biomimicry, and it’s helping scientists create a new LED that’s more than one and a half times as efficient as the original.
A team of researchers from Belgium, France, and Canada took a close look at the flickering firefly, a bug with a flashlight behind that’s delighted humans for centuries. Apparently, the scientists identified an unexpected pattern of jagged scales that enhanced the lanterns’ glow, and applied that knowledge to LED design to drastically improve efficiency.
Fireflies create light through a chemical reaction that takes place in specialized cells called photocytes. The light is emitted through a part of the insect’s exoskeleton called the cuticle. Light travels through the cuticle more slowly than it travels through air, and the mismatched scales discovered by the scientists help minimize internal reflections, meaning more light escapes to reach the eyes of potential firefly suitors.
Using the firefly’s jagged scales as a guide, the team created an LED overlayer that increased light extraction by up to 55 percent. They say it could be easily tailored to existing diode designs to help humans light up the night while using less energy. “What’s nice about our technique is that it’s an easy process and we don’t have to create new LEDs,” said Annick Bay, a Ph.D. student at the University of Namur in Belgium, and one of the authors of the paper published in the journal Optics Express.. “With a few more steps we can coat and laser pattern an existing LED.”