Solar energy can be converted into a liquid fuel, utilizing a new bionic leaf designed by researchers at Harvard University and the Wyss Institute for Biologically Inspired Engineering.

An artificial leaf, recently developed by a team led by Daniel Nocera at Harvard University, creates oxygen and hydrogen. A bacteria called Ralstonia eutropha then consumes the hydrogen gas, and converts it into protons and electrons. These are integrated into molecules of carbon dioxide as part of the reproductive cycle of the bacteria.

This new energy approach utilizes the bacteria to effectively convert sunlight into fuel, creating a synthesis of artificial technology and biology.

"This is a proof of concept that you can have a way of harvesting solar energy and storing it in the form of a liquid fuel... we had a mission of wanting to interface some kinds of organisms with the harvesting of solar energy. It was a perfect match," Pamela Silver of the Wyss Institute said.

The news comes as consumers and government leaders are eager to tap alternative fuel and energy sources given increasing prices within the oil, gas and electric marketplaces. One of the earliest alternative energy options, solar cells, has not caught deep traction. One reason is a lack of infrastructure supporting solar cell energy use for vehicles, despite more electric cars hitting the roadways. Another reason that may be stemming alternative fuel use is consumer habit and behavior.

It is possible that green energy options such as the new bionic leaf and traditional solar cells could each find their own niche in future energy use. One day, homes and businesses might regularly be powered by solar cells, while vehicles are powered by liquid fuel generated by bionic leafs. A similar fate awaited the great debate between famed inventors Thomas Edison and Nikola Tesla over AC versus DC power. While AC is used to transmit electricity, many home appliance and electronic devices run on DC.

Harvard researchers Silver and Nocera started to collaborate over a common interest in "personalized energy," which is the manufacturing of energy sources on a local level. This new method could be utilized in remote areas, with little access to infrastructure.

The invention of the new bionic leaf was profiled in the Proceedings of the National Academy of Sciences of the United States of America.