This Self-Sustaining, Bacteria-Powered Fuel Cell Can Generate Power for 13 Straight Days

Binghamton University researchers, with the help of their colleagues from State University of New York, have developed the first ever micro-scale self-sustaining microbial fuel cells powered by the symbiotic interactions of two types of bacteria.

Their work, described in a paper published in the Journal of Power Sources, is the next step in the field of microbial fuel cells.

"This concept of creating electricity through synergistic cooperation is not new. However, much of this work is still in its nascent stages," said Seokheun Choi, an assistant professor of Electrical and Computer Science at Binghamton University and co-author of the study, in a press release. "The evolution of this technology will require additional exploration, but we, for the first time, realized this conceptual idea in a micro-scale device,"

For the new fuel cell, the researchers first place a mixed culture of phototrophic and heterotrophic bacteria in a cell chamber that is about 90 microliters, or one-fifth the size of a teaspoon. The phototrophic bacteria create its own food using sunlight, carbon dioxide and water, while the heterotrophic bacteria feed on organic materials, which are the phototrophic bacteria in this case.

The researchers exposed the cell to sunlight and added an initial dose of food for the heterotrophic bacteria. Through cellular respiration, the heterotrophic bacteria produce carbon dioxide, which is then used the phototrophic bacteria to start the symbiotic cycle.

After establishing the symbiotic cycle, the researchers stopped adding extra food for the heterotrophic bacteria. The researchers also made sure that there are enough phototrophic bacteria to sustain the metabolic process of heterotrophic bacteria.

The metabolic process of the symbiotic interaction produced an electric current, about 8 microamps per square centimeter of cell, for 13 consecutive days. The power produced by the symbiotic interaction between the two bacteria generated a power that is about 70 times greater than current produced by phototrophic bacteria alone.

Despite the promising breakthrough, the researchers noted that bacteria-powered cells are still in its early step and requires more research.