As we have already written, Hidden wonders of nature may have important implications for the renewable energy industry. After the owls’ wings studied to solve the wind turbines noise problem, insect eyes have inspired Stanford University researchers to create a new generation of advanced photovoltaics.
According to a new study results, published in the journal Energy & Environmental Science (E&ES), the Stanford team used the eye of the fly design to protect a fragile photovoltaic material called perovskite from deteriorating when exposed to heat, moisture or mechanical stress.
“Perovskites are promising, low-cost materials that convert sunlight to electricity as efficiently as conventional solar cells made of silicon,” said Reinhold Dauskardt, a professor of materials science and engineering and senior author of the study. “The problem is that perovskites are extremely unstable and mechanically fragile. They would barely survive the manufacturing process, let alone be durable long term in the environment.”
To address the durability challenge, the Stanford team confided in nature.
Researchers were inspired by the compound eye of the fly, which consists of hundreds of tiny segmented eyes. It has a beautiful honeycomb shape with built-in redundancy: If you lose one segment, hundreds of others will operate. Each segment is very fragile, but it’s shielded by a scaffold wall around it.
Using the compound eye as a model, the researchers created a compound solar cell consisting of a vast honeycomb of perovskite microcells, each encapsulated in a hexagon-shaped scaffold just 0.02 inches (500 microns) wide.
Tests conducted during the study revealed that the scaffolding had little effect on how efficiently perovskite converted light into electricity and to figure out if the new device withstand the kind of heat and humidity that conventional rooftop solar panels endure, the researchers exposed encapsulated perovskite cells to temperatures of 185 F (85 C) and 85 percent relative humidity for six weeks. Despite these extreme conditions, the cells continued to generate electricity at relatively high rates of efficiency.