A Northwestern University team has developed a microbial fuel cell that can generate electricity from soil as microbes break down dirt. The device, shaped like a cartridge and buried in soil, consists of a disc-shaped carbon felt anode at the bottom and a conductive metal cathode on top.
The design ensures continual access to oxygen and water, addressing previous challenges with microbial fuel cells in low-moisture conditions. In testing, the device consistently generated power across different soil moisture levels and could potentially power small sensors for long periods without regular battery changes. The components are off-the-shelf and easily accessible for widespread commercialization.