One day the engine used by plants and photosynthetic bacteria to convert sunlight to chemical energy could power a cell phone or laptop, or help produce hydrogen fuel for cars and homes.

And one University of Tennessee scientist will be able to say he did his part.

UT biochemist Barry Bruce and his collaborators at the Massachusetts Institute of Technology incorporated a plant`s ability to make energy in a solid-state electronic device three years ago.

MIT researchers called it the world`s first photosynthetic solid-state solar cell.

The main source of the plant proteins used in the research: spinach.

It`s inexpensive, sustainable and readily available, according to Bruce.

His work got him named one of 10 global "Revolutionaries" in the May edition of Forbes magazine. He was listed among "10 People Who Could Change The World."

"I`m one scientist at one university, with five or six people working on this," he said. "This is probably something that`s going to take decades."

Since publication he`s had several e-mails from people all around the world, sending him ideas and mostly showing support, he said. The magazine article also has been a distraction for Bruce.

"Sustainability is something that people all over the planet are passionate about," he said. "So when they see somebody working on something that might have any hint of a green approach to energy, they get excited."

Bruce, a professor at UT`s Center for Environmental Biotechnology, doesn`t hype the research.

The solar cell the group fabricated didn`t provide enough electricity to fuel any electronic devices, he said.

"There`s not enough current there to power anything," said Bruce, 50. "But there`s enough power to be measured."

MIT researchers described the solar cell as a "spinach sandwich." The protein complexes are assembled in tiny groups, 10 to 20 nanometers wide, according to an MIT news release. A human hair is about 80,000 nanometers wide, according to the National Nanotechnology Initiative.

The bottom layer of the cell or electronic device is transparent glass coated with a conductive material.

When light hits the device, the scientists got current, but not a lot of it, said Marc Baldo, assistant professor of electrical engineering at MIT and one of Bruce`s collaborators. He said that was mostly because there was a "thin layer" of the complexes.

Researchers are looking at the solar cell`s ability to produce electrons that could catalyze hydrogen.

Bruce said it`s a system that has lot going for it.

"It`s completely sustainable, and it can be carbon neutral," he said. "It`s inherently decentralizing, which means basically the sun shines everywhere."