Researchers at the University of California, Los Angeles fed the bacteria with silver and turned them into fuel cells.
Microbiological fuel cells are the technology of the future for generating electricity, but scientists don’t yet know how to make it efficient. The authors of the new work from the University of California at Los Angeles have found a way to generate energy in this way with greater efficiency.
There are bacteria that produce electrons through normal metabolic processes. In this way, electricity can be generated from microbial fuel cells. Previously, scientists grew such bacteria in films on electrodes, fed them with organic matter, and got a device that generates electricity and purifies wastewater. But this technology had very low efficiency and worked at a loss.
Now scientists have found a way to increase the amount of electricity they generate: They used the Shewanella oneidensis bacterium, which survives even in low oxygen levels.
The authors grew bacteria on graphene oxide electrodes with silver ions inside. Next, the authors implanted transmission wires into the bacteria. As a result, the bacteria converted these ions into nanoparticles, which are embedded in their cells. This way, more ions leave their membranes.
The bacteria now transfer 81% of the electrons produced to the electrode and generate 0.66 milliwatts of power per square centimeter. This is the highest among peers.