Fireflies could help make organic light-emitting diodes (OLEDs) significantly more efficient, Korean researchers say.
Fireflies, which generate bioluminescent light more efficiently than many other animals, use their glow to attract mates. Previous research suggests that this efficiency was due not only to the chemicals that the insects use to produce light, but also to the lantern that holds these chemicals.
After fireflies generate light, it passes through a transparent lantern made of chitin. Light travels through chitin more slowly than it travels through air, and this mismatch would ordinarily cause a fraction of the firefly's light to be reflected back into the lantern—much like the way light bounces around inside optical fibers instead of escaping from them. However, nanostructures and microstructures on the lantern help reduce this reflection, boosting the emission of light.
Biomimetic engineer Ki-Hun Jeong and his colleagues at the Korea Advanced Institute of Science and Technology (KAIST) focused their attention on microscopic structures on the firefly lantern. The structures resemble scales, and the scales are covered in nanoscale grooves. The researchers fabricated replicas of these natural photonic structures from silicone rubber and then covered OLEDs with them. “Our biologically inspired OLEDs have a very similar configuration with the firefly lantern,” Jeong says.
The scientists discovered these firefly-inspired structures could boost OLED efficiency by up to 61 percent. They detailed their findings in the 25 March online edition of the journal Nano Letters.
Now the researchers are “looking for an industry partner to commercialize bio-inspired OLEDs for killer applications,” Jeong says. “We strongly believe that biologically inspired OLEDs open a new paradigm for engineering biomimetics for lighting applications.”