Dirt-Powered Bacteria Batteries
Bacteria are one of the most abundant organisms on the planet and also one of the most studied. Today, scientists use bacteria for genetics research, antibiotics, and yes! Even biofuels. Recent technological advances have made a battery running on bacteria a reality. Known as microbial fuels cells or MFCs, batteries running on bacteria and other microbes have been keenly researched by scientist for decades.
How bacteria powered batteries work
Contrary to popular belief, bacteria do not directly produce electricity in a MFC. Bacteria powered batteries use the chemical energy generated by bacteria, and convert it into electrical energy using a relatively simple mechanism. Like most batteries, a bacteria powered battery has an anode (the negative end) and a cathode (the positive end). In addition to the anode and cathode, a bacteria powered battery also has a membrane capable of filtering electrons (anions) and protons (cations) produced during the chemical breakdown of substances by bacteria.
Once the bacterial breakdown starts producing ions, the anions are transferred from the cathode compartment via an external circuit and the protons are sent to the cathode from the anode. In a nutshell, the chemical energy generated by bacterial activity is converted to electrical energy.
Unfortunately, not all bacteria are electrochemically active and require a substance known as a ‘mediator’ to facilitate the flow of ions. Substances like thionine, methyl viologen, methyl blue, humic acid and neutral red were used as mediators but their toxicity was a major concern for scientists. A few years back scientists engineered electrochemically active bacteria, and the science of bacteria powered batteries took a huge leap forward. Mediator less MFCs can run on everything from waste water to a simple saline solution and are truly environment friendly batteries.
Recent developments
Harvard scientists working under the Lebone banner have created a bacteria powered battery that uses bacteria found in African soil. What is truly remarkable about the MFC created by Lebone is that the battery uses a layer of sand as the ionic membrane, mud with manure as the bacterial substrate, and a graphite cloth as the anode.
Like most eco-friendly and renewable solutions, the MFC created by Harvard scientists uses substances readily available throughout Africa and is expected to provide electricity in remote parts of Africa. In fact, the only non-biodegradable substance used in the bacteria powered battery created by Lebone scientists is probably the 5 pound plastic bucket used to case the battery. Although the amount of energy produced by the bacteria powered battery is far from amazing, it can produce enough power to run a few LED lights and small electronics.
The future of bacteria powered batteries
Organizations like Lebone are one of the many organizations that are investing time and money in creating truly eco-friendly renewable energy options. The quest for a truly eco-friendly energy source may not have ended with bacteria powered batteries, but MFCs are a step forward in the right direction. With regular batteries clogging waste grounds the world over, recyclable energy sources like bacteria powered batteries are necessity.
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October 21st, 2009
I follow you on FCBK. Lots of friends of mine here in Mexico are getting to know all kind of alternative energy updates thanks to you. We all, be sure of that, appreciate it very much.
Greetings!
October 22nd, 2009
All this sounds genius, why aren’t we putting it all to work now?
October 22nd, 2009
To exercise power costs effort and demands courage. That is why so many fail to assert rights to which they are perfectly entitled – because a right is a kind of power but they are too lazy or too cowardly to exercise it.
October 22nd, 2009
Not sure if i like the idea of bacteria in all my gadgets. what are the safeguards to stop people catching stuff from the bacteria?
October 22nd, 2009
There is good and bad bacteria like people,m unfortunately bad people lie to us like GORDO and his liberal machine.
October 22nd, 2009
Ray: The article makes it pretty clear that the bacteria stay IN the battery and what goes into your gadgets is electrons. Your gadgets need electrons to run; they couldn’t run on bacteria. All power-generating technology is aimed at getting electrons moving around a circuit; if you use coal, hydro or nuclear to generate electricity, it doesn’t mean there’s coal, water or radiation in your gadgets! Same thing here.
October 22nd, 2009
Okay, I guess it needs to be mentioned that they don’t appear to be talking about tiny batteries that go inside gadgets, either. They’re talking about a battery the size of a bucket, which you would have to hook your gadget up to.
October 22nd, 2009
Isn’t this more a fuel cell than a battery? You don’t charge it with electic and then discharge it. You add a fuel (waste water) and it is broken down and the result is electric.
October 23rd, 2009
I agree, matt peffly. In many contexts, to many people, the difference between a fuel cell and a battery is unimportant, but to this audience the mistake just comes off as weird.
Similarly, when the writer claims this produces little energy, then I wonder what’s the point. Or was the writer simply confusing energy and power?
October 25th, 2009
Seems like an amazing piece of technology for a third world farmer. I wonder what the byproduct of a dead battery would look like? Would it simply be composted material, ready to be added to the soil, or at least to existing compost? How difficult is it to scale this up say…10x-100x?
If the answers to these questions are positive, then many people in the poorest parts of the world could benefit greatly. Still, for the developed world this seems of very limited use.
November 16th, 2009
Any clean form of energy of energy is worth exploring and this could make a big difference for the world’s poorest people
March 10th, 2010
Most bacteria do not affect humans. All virus and bacteria can only affect a certain animal species, meaning that they are very specific, like enzymes. This means that what could kill your fish or dog will not harm you.
March 10th, 2010
Also, why does it matter if it helps the poor? We should be using this for major cities in the form of giant bacteria pool power plants. Most of the pollution is produced from the first world countries so lets fix the rich before we worry about the poor.