Plants can turn sunlight into energy faster than any man-made process ever has. How fast? Try one quadrillionth of a second. Now, scientists in the US, Australia, and the UK have begun mimicking photosynthesis to design a new generation of efficient solar-energy cells.

Inside plants, tiny molecules each perform specific tasks to convert light into energy. That division of labor is one key to a plant's efficiency. Now, nanoscience can copy nature. Scientists can build devices that work together, but are each responsible for a different function. And they have created a device that can absorb light and efficiently convert it to electrical current.

Think of it as an artificial leaf. It continually turns sunlight into chemical energy. Cleanly and efficiently. Artificial photosynthesis could become a carbon-neutral source of electricity, fuel for transportation and more. That means it wouldn't contribute to global warming as the result of burning oil and coal.