Engineers at Princeton University have mimicked the folds and wrinkles of leaves to create a solar cell, which they claim is far more effective than those with a flat surface.

In a report published in the journal Nature Photonics, the team claims that their design is capable of producing 47 percent more electricity than comparable solar cells without these topographical quirks. The wrinkles and deep folds, they say, "guide and retain light within the photo-active regions of photovoltaics".

Treehugger adds that the engineers used "ultra-violet light to cure a layer of liquid photographic adhesive, alternating the speed of curing to create both shallower wrinkles and deeper folds in the material".


Jong Bok Kim, the paper's lead author said the results were far better than predicted: "I expected that it would increase the photocurrent because the folded surface is quite similar to the morphology of leaves, a natural system with high light harvesting efficiency. However, when I actually constructed solar cells on top of the folded surface, its effect was better than my expectations."

In particular, the design saw 600 percent more light absorption at the infrared end of the spectrum. The added wrinkles and folds also made the plastic solar cells stronger. "A standard plastic solar panel would see an efficiency dive of 70 percent after bending, but the leaf-like cells saw no diminished effects. This tough flexibility could lead to the cells being incorporated in electricity-generating fabrics or windows and walls", says Treehugger.

Biomimicry has often been used in designing solar panels. Last year, Wired.co.uk reported on an array of photovoltaic cells shaped like ivy leaves that could be used to coat buildings. Solar Ivy was developed by New York-based Sustainably Minded Interactive Technology (SMIT) with funding from the University of Utah.

MIT professor Daniel Nocera released details last year of an artificial leaf he had created that he claimed was ten times more efficient than the real thing. The advanced solar cell is left to float in a pool of water where it uses sunlight to split water into oxygen and hydrogen -- these are then stored in a fuel cell to be used when producing electricity. As Wired.co.uk stated: "With a single gallon of water, Nocera says that the chip could produce enough electricity to power a house in a developing country for an entire day."

The scientist has now signed a contract with Tata Group to commercialise the idea.