The “Green is the New Crimson” banners festooned on buildings at Harvard Medical School are visible signs of Harvard’s commitment to the environment. But behind those banners, students and faculty are tackling this problem in less visible—but equally important—ways.

Earlier this month, Faculty of Arts and Sciences Dean Michael D. Smith touted Harvard’s “world-class research” as a fundamental aspect of what the University is doing to “make a long and lasting contribution to this issue [of climate change] from an intellectual point of view.”

And across campus, undergraduates, graduate students, and professors at Harvard Medical School and the School of Engineering and Applied Sciences are tackling the challenge head on, using bacteria, dirt, and oxides to create clean and efficient energy.

DIRT CHEAP ENERGY

Last fall, biomedical engineering professor David A. Edwards assigned one of the student groups in his engineering class the task of finding a way to light London for the 2012 Olympics.

The group members, many of whom were international students from Africa, told him that they were more interested in finding ways to provide light to their home continent.

“Five hundred million people live in Africa without electricity,” said David M. Sengeh ’10. “When I was growing up in Sierra Leone we had one lamp at our table for 10 people.”

He recalled going to sleep early in the evening and waking up in the middle of the night to study so he could focus with the light just for himself.

Along with fellow undergraduates and alumni, Sengeh co-founded Lebone Solutions to work towards what they termed “growing energy”—combining green technology with local ownership.

“Change for people in any community can only be done if you do it along with people in that community,” Sengeh said.

This summer, the students from the group traveled to Tanzania with the support of the Harvard Initiative for Global Health and the Idea Translation Lab to experience Africa firsthand and test their technology: microbial fuel cells, devices that convert chemical energy to electrical energy, and light emitting diodes.

“This was one of the first light focused microbial fuel cells tested in Africa,” said W. Hugo Van Vuuren ’07, one of the cofounders of Lebone who now works with the Idea Translation Lab.

This “energy from dirt” technology—which can be implemented using local materials—developed from the research of Peter R. Girguis, a professor of organismic and evolutionary biology.

“Most soils harbor bacteria and the bacteria are living and therefore transmitting electrical signals basically through the soil,” Edwards said. “By creating an anode-cathode setting in the soil, it’s actually possible to draw current and therefore generate energy.”

This academic year, Lebone aims to work with other groups to bring its technology to developing countries. Over the next 18 months, the group’s founders hope to finalize the technology with support from the World Bank—they were one of the winners of its Lighting Africa Competition 2008—and a private donor, so that they have a final product ready to distribute.

“There is an abundance of research and these technologies are around but they just don’t get to people who need them,” Sengeh said.

LIVE SOLAR PANELS

Pamela A. Silver, a professor of systems biology at the Medical School, is also developing a bacterial fuel cell using synthetic biology, the application of computer-systems logic to biology.

Silver’s lab is trying to use genetically-engineered bacteria to convert sunlight into hydrogen, a clean energy source.

“We had already built cells that can count, remember, [and] do memory storage, but they were sort of ‘toy’ systems,” Silver said. “We were sitting around asking ‘what can we really do that can change the world?’ and we decided to bite the bullet and work on bio-engineering.”

The project combines research from two traditionally-distinct areas of engineering: genetic (modifying the bacteria to produce charge flow) and chemical (running electricity through water to produce hydrogen).

“Each of these things are black boxes,” Silver said. “You hook them together and you treat it like you would building a computer.”

Silver said that if successful, bacteria fuel cells would be both more economical and more environmentally-friendly than manufactured fuel cells. The cells use cyanobacteria, which has a well-characterized genome sequence, and is cheap, easy to grow, and able to be produced without heavy machinery and materials.

“They are self-replicating machines that do not require irritating minerals or mining,” Silver said.

Another advantage to solar-sensitive bacteria is that their energy source is renewed daily.

“When you are trying to build systems it includes putting in an energy source,” Silver said. “The home run is if we can use sunlight.”

PLAYING IT COOL

Researchers at SEAS are also developing innovative fuel cells, but moving away from traditional fuels like hydrogen and oxygen to hydrocarbons.

Solid oxide fuel cells, which use hydrocarbon fuels like propane and butane, are costly to manufacture because they must operate at very high temperatures—over 800 degrees Celsius. But Shriram Ramanathan, a professor of materials science at SEAS, has developed cells that can operate at less than 500 degrees.

Working with Harvard’s Office of Technology Development, Ramanathan created SiEnergy, a spin-off that received $500,000 last year from Allied Minds, a venture capital investment firm that focuses on innovative early-stage technologies, to develop their low-temperature fuel cell technology.

Ramanathan’s current research focuses on metal oxides, a class of ceramic materials.

“Most of our research is related to how processing or synthesis of these materials affects their functional properties,” Ramanathan said.

His lab is looking at high-temperature ion transport through oxides—an issue of importance for energy conversion devices.

“If one can make viable sustainable devices which work well and are inexpensive to manufacture,” Ramanathan said, “one can make fuel cells practical for transportation applications.”

—Staff writer Alissa M. D’Gama can be reached adgama@fas.harvard.edu.

—Staff writer Natasha S. Whitney can be reached nwhitney@fas.harvard.edu.