Via The Verge
The wings of a butterfly have inspired a new type of solar cell that can harvest light twice as efficiently as before and could one day improve our solar panels.
Solar panels are usually made of thick solar cells, and are positioned at an angle to get the most amount of light from the sun as it moves throughout the day. Thin film solar cells, which can be only nanometers thick, have a lot of potential. These are cheaper and lighter, but because they’re less efficient, we usually use them only in watches and calculators, instead of solar panels. Scientists studied the black wings of the rose butterfly, and copied the structure to create thin solar cells that are more efficient. Unlike other types of cells, these can absorb a lot of light regardless of the angle, and are also easy to make. The results were published in the journal Science Advances.
The rose butterfly is native to Southeast Asia. Because it is cold-blooded and needs sunlight to fly, its black wings have evolved to be very good at absorbing energy. “The really interesting thing is that the butterflies, which have evolved these complex structures as a result of selection over millions of years, are still way outperforming our engineering,” YaleNUS College biology professor Vinod Saranathan told The Verge in an email. (Saranathan was not involved in the study.)
To figure out why these butterflies are so efficient, scientists led by Radwanul Siddique, a bioengineer at the California Institute of Technology, looked at wings under an electron microscope and created a 3D model of the wings’ nanostructures. The wings are built from tiny scales that are covered in randomly spaced holes. The holes are less than a millionth of a meter wide, and they help scatter the light and help the butterfly absorb heat.