Those moths flying around your porch light may be annoying to you but they’re inspiring engineers working on improving solar cells and making windows more energy efficient. Using patterns based on the shape of moth eyes, ultra-thin graphene sheets are being designed to more effectively capture light.
Professor Ravi Silva, head of the Advanced Technology Institute at the University of Surry explains,
Moth’s eyes have microscopic patterning that allows them to see in the dimmest conditions. These work by channeling light towards the middle of the eye, with the added benefit of eliminating reflections, which would otherwise alert predators to their location. We have used the same technique to make an amazingly thin, efficient, light-absorbing material by patterning graphene in a similar fashion.
Graphene, a sheet of pure carbon that is as thin as an atom yet a hundred times stronger than steel, is highly pliable and can conduct heat and electricity. Untouched, it can absorb only 2.3% of light. Researchers have recently shown that through manipulation and coating, this rate increases to 95% across a broad spectrum from UV to infrared.
Dr. José Anguita of the University of Surrey, lead author of the study, says,
Nanotexturing graphene has the effect of channeling the light into the narrow spaces between nanostructures, thereby enhancing the amount of light absorbed by the material.
This new technology has many applications, according to Dr. Silva:
Solar cells coated with this material would be able to harvest very dim light. Installed indoors, as part of the future ‘smart wallpaper’ or ‘smart windows,’ this material could generate electricity from waste light or heat, powering numerous smart applications. New types of sensors and energy harvesters connected through the Internet of things could also benefit from this type of coating.
The Surrey team developed this technology in cooperation with BAE Systems for infrared imagery in EMS (environmental management system) devices. By partnering with innovative companies, they hope to explore future applications of this new technology.
Already, graphene may transform consumer electronics by allowing for bendable smart phones, quick-charge batteries and unbreakable touch screens. The new coating opens up even more possibilities.
Show these moths a little gratitude – leave the porch light on and turn off that bug zapper.