Fireflies Inspire Better, Cheaper LEDs
It seems like every week there is another bimimicking technology that is inspired by one insect or another. The iridescence of butterfly wings have inspired holographic solar panel coatings, water strider insects have inspired water-striding robots, bumblebee behavior is inspiring better computers and that's just scratching the surface. Now, it's the firefly's turn.
The structure of the firefly's lantern has led to the development of anti-reflective LED lenses that are cheaper and make the technology even more efficient. Researchers from Korea Advanced Institute of Science and Technology, Firefly Institute, Korea Basic Science Institute, and Korea Research Institute of Standards and Science, began by studying the structure of the lantern with a scanning electron microscope to see how the layers allow for light. Their studies revealed that the intricate structure of the lantern reduces optical impedance between air and the cuticle, which acts as an anti-reflective layer, preventing loss of light and raising efficiency.
The researchers then developed an LED lens mimicking those structures that included creating tiny nanoscale etched dots on the surface of the lens similar to the ridges found on a firefly lantern. The result was a lens that lets 98 percent of light through, better than conventional anti-reflective coatings and an improvement that could increase the overall efficiency of LEDs.
The other major breakthrough was that compared to the traditional way of coating of LED lights uses injection molding in two-part process, but they were able to create the new coating with just a single-step injection molding process, which could cut the cost of LEDs.
The findings were published in the most recent Proceedings of the National Academy of Sciences.