Microbial fuel cells produce an electric current from the microbial decomposition of organic compounds. Assuming we could commercialize the process, this could conceivably make our planet a virtual battery. But how practical are organic-soil microbial fuel cells in the real world? We decided to explore this intriguing topic further.
Our subject for today was originally the brainchild of Michael Cressé Potter in 1911. He was a botanist, mycologist, phytopathologist, herbarium curator, and canon in the church. Potter managed to generate electricity from a species of yeast. However, his idea did not really take off, until Australian scientists produced a prototype using brewers yeast in May 2007.
How Do Organic-Soil Microbial Fuel Cells Work in Practice?
Modern organic-soil microbial fuel cells are similar to batteries, in that they use chemical energy to generate electricity. They have two electrodes in separate compartments. The anode compartment containing the bacteria is oxygen-free, unlike the cathode that does contain oxygen.
The electrons travel from the anode to the cathode through a paste, likely to be manganese oxide, according to Let’s Talk Science. At the cathode, the electrons experience a reduction reaction. This movement creates an electric current, that could, for example, power a light bulb.
Research Points to a Practical Use for Technology
Our research took us to a post by Design Products and Applications dated January 18, 2024. The article described work by a team at Northwestern University in Evanston, Illinois. They tested a new organic-soil microbial fuel cell that powered sensors, measuring soil moisture, and detecting touch. The cell also had a tiny antenna transmitting data to a base station.
“In a search for solutions, we looked to soil microbial fuel cells,” the team explains. “These use special microbes to break down soil, and use that low amount of energy to power sensors. As long as there is organic carbon in the soil for the microbes to break down, then the fuel cell can potentially last forever.”
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Power from the Soil Beneath Our Feet
