'Moth Eye' Graphene Breakthrough Could Create Indoor Solar Cells

graphene indoor solar cell university of surrey moth eyes
Researchers studied the eyes of moths to create sheets of graphene they claim to be the most light-absorbent material ever created. University of Surrey

A scientific breakthrough with the "wonder material" graphene has opened up the possibility of indoor solar cells that capture energy from indirect sunlight, as well as ambient energy from household devices.

Researchers from the University of Surrey in the U.K. studied the eyes of moths to create sheets of graphene that they claim is the most light-absorbent material ever created. The energy capture method could be used to power Internet of Things (IoT) devices, such as smart clothing, wearables and smart wallpaper.

"We realized that the moth's eye works in a particular way that traps electromagnetic waves very efficiently," Professor Ravi Silva, head of the Advanced Technology Institute at the University of Surrey, tells Newsweek . "As a result of our studies, we've been able to mimic the surface of a moth's eye and create an amazingly thin, efficient, light-absorbent material made of graphene."

Graphene, first created in a laboratory by researchers in 2004, has been touted by scientists as a wonder material due to its remarkable properties and vast potential. The one-atom thick material, consisting of carbon atoms in a honeycomb lattice, is 200-times stronger than steel, more conductive than copper and as flexible as rubber. These properties could potentially be used to create everything from flexible smartphones, to artificial retinas.

"For many years people have been looking for graphene applications that will make it into mainstream use," Silva says. "We are finally now getting to the point where these applications are going to happen. We think that with this work that is coming out, we can see an application very close because we've done something that was previously thought impossible: optimizing its incredible optical properties.

"Organic solar cells are based on polymers and these only really capture energy from the visible range. Now with the materials we have, it transcends all of that by being able to absorb over a much larger range. What we need to do is come up with a technology that allows you to use that efficiently, such as rectennas."

Rectennas—or rectifying antennas—are a special type of antenna that can convert electromagnetic energy into direct current (DC) electricity. First conceived in 1964, Silva says rectennas are yet to realize their real-world potential.

Combined with Silva's graphene breakthrough, rectennas would be able to efficiently capture and convert energy from ambient microwave and radio frequencies from household devices, such as smartphones, computers and lightbulbs. This scavenged energy could then be used to power smart sensors and IoT devices without the need for batteries or wired connectivity.

The research is published in Science Advances.