Microbial Battery

Microbial Battery

Finding new ways to generate energy from natural occurring events is a popular field of study in science today. An article I discovered, written just last week, discusses how Stanford engineers found a way to generate electricity from sewage water. It involves the use of two electrodes that are plugged into a bottle of wastewater. Inside the wastewater “an unusual type of bacteria feast on particles of organic waste and produce electricity that is captured by the battery’s positive electrode.” (Abate, Stanford)

Currently this is just a small scale prototype, but this discovery can lead to much better efficiency in how countries deal with their wastewater. The scientific community has known about these exoelectrogenic microbes, but has been unable to use this energy as efficient as they would like. Exoelectogenic microbes are “organisms that evolved in airless environments and developed the ability to react with oxide minerals rather than breathe oxygen as we do to convert organic nutrients into biological fuel.” (Abate, Stanford) The microbial battery is a simple design with great efficiency that is able to capture the energy from these bacteria. The microbes are very small, in fact over one hundred of them can fit side by side in the width of a single human hair. The microbes themselves are white tubes that attach to the carbon filaments of the battery, where they “serve as efficient electrical conductors”. (Abate, Stanford) The Stanford engineers were able to capture images, through a scanning electron microscope, of the microbes “attaching milky tendrils to the carbon filaments”. (Abate, Stanford) This showed the Stanford team that the microbes were creating a way to dump off their excess electrons. The excess electrons flowed into the carbon filament and across the positive electrode (made of silver oxide) where they reduced the silver oxide to silver and storing

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