DIY Living Computer Battery

An anonymous reader writes "Talk about a living battery/pollution clean up/environmentally friendly battery, this seems to fit all the buzz words. Researchers at UMass reported in the journal Science about their sediment battery. 'Derek R. Lovley, UMass microbiologist and team leader, explained how the team used water and sediment from Boston Harbor, a collection of mason jars, ordinary electrical wiring and sterile graphite electrodes to determine the science behind the mechanics of a simple, sediment battery. Using Desulfuromonas acetoxidans (a Geobacter bacteria) the researchers were able to produce enough electrical current to power a lightbulb or a simple computer.'" The linked article is low on details - post 'em in the comments if you have more information on related projects.

Comments

Article info

[danimrich]

This is the corresponding article in Science:

Electrode-Reducing Microorganisms That Harvest Energy from Marine Sediments
Daniel R. Bond, Dawn E. Holmes, Leonard M. Tender, and Derek R. Lovley
Science 2002 January 18; 295: 483-485. (in Reports)

Re:Article info

[br0ck]

Here is the full text of the Science article in PDF format. Use Google to parse this into HTML.

More information on microbial power plants

[juushin]

As far as more information on Lovley's study, there aren't many details floating around. The article still hasn't appeared in print in Science (possibly this week). I did find some press releases from UMass that shed a bit more light on their work:

http://www.umass.edu/newsoffice/archive/2002/01170 2electrodes.html

http://www.umass.edu/newsoffice/archive/2002/11130 2harbor.htm

Original paper published January 2002...

[Olinator]

...And entitled "Harnessing Microbially Generated Power on the Seafloor" can be found in PDF format at http://zdna.micro.umass.edu/publications/12091916. pdf. The basic idea is to use geobacter organisms (which occur naturally in various places, such as the mud on the bottom of Boston harbor) to generate electricity, by giving them a graphite anode to colonize.

Ole

Details, details, details

[kowaikawaii]

Details...

They've actually put two of these things up in field sites, and it works well in both polluted (Tuckerton, NJ) and unpolluted (Newport, OR) areas. The energy it's harvesting is from the difference between the oxidizing environment we live in and the reducing environment in which sediment bacteria turn organic matter into methane (and no, the methane can't be effectively harvested.)

The good news is that the power supply was very steady over 3 months. The bad news is that the power so low as to be useless - it averaged at 28 MILLIwatts per square meter. The area needing to be covered in order to run a lightbulb is left as an exercise for the reader, but the answer's big. They're currently thinking this might be a good way to power long-term monitoring devices deployed in the middle of the ocean and other distant places, but as a practical power source - go get a photovoltaic!

Re:Modern "Potato Clock"

[4ginandtonics]

There's a bit of a bonus with the potato clock, you know. You can use the byproduct to run your new hydrogen fueled car:

From http://www.quantumscientific.com/pclock.html

The potato contains phosphoric acid. This acid causes chemical reactions to occur at each of the electrodes (galvanized nail and copper penny). The reaction at the copper electrode strips electrons from the copper and attaches them to the Hydrogen ions (2H+) in the phosphoric acid. This depletes the electrons on the copper electrode which makes it "hungry" for more. The process creates Hydrogen gas.

Ok, well, maybe you would really really big potato battery, or a really really tiny car...

Re:The possibilities

[Simon Field]

The creek near your house might be better put to use as a hydroelectric generator.

Biological fuel cells have been around for a long time. The ones we built in high school used yeast.

Here is more information on Desulfuromonas acetoxidans. You can buy pure cultures here.

An article with more information (didn't Hemos ask?) is here.

Re:Copper + ZInc + Acid

[SiliconEntity]

The "potato clocks" and such are misleading. You're not getting the power from the potato. The power comes from the electric differential between the two electrodes of dissimilar metals. The potato just supplies an electrolyte. You can get exactly the same effect by sticking the electrodes into salt water. The metals gradually dissolve away, and when they're gone the system can't generate any more power.

Re:Why?

[Simon Field]

A quote from this article:

Lovley's group also has found that some Geobacters can convert toxic organic compounds, such as toluene, to electricity. Lovley says this suggests that some Geobacters can be used to harvest energy from waste matter, or can be included in technology used to clean up subsurface environments contaminated by organic matter, especially petroleum. Earlier studies had shown bacteria could produce electricity under artificial conditions in which special chemicals were added, but the UMass study was the first to prove that the nearly ubiquitous microbes living in a typical marine environment could produce electricity under the conditions naturally found in that environment.

"Once we know more about the genome of Geobacters, we will be able to manipulate these organisms to make them receptive to a variety of organic or inorganic contaminants. Theoretically, when they begin to degrade the contaminant, they will throw electrons on an electrode, and that could set off a light, a sound or some other form of signal," Lovely said. "An understanding of how this phenomenon operates has a number of extremely timely applications, especially in developing technologies to recognize toxins and organic contaminants." Lovley cites, for example, the potential for using such technology to develop military equipment that could alert soldiers to the presence of toxins or biological warfare agents in the immediate environment.

The Office of Naval Research funded this study.

Just because you can only think of one use for a technology, don't be quick to label it useless.

Other uses might be to power seafloor monitoring instruments, or just to indicate that some interesting reaction is taking place.

another reference to it

[Anonymous Coward]

ZZZ has an article on the sediment battery here from a while ago (scroll down a bit). I'm wondering how many jars would be needed to have any sort of effective power source...not to mention inconsistent power depending on sunlight or something :-)

Re:Modern "Potato Clock"

[Anonymous Coward]

Actually "potato batteries" are just regular batteries : Two electrodes of different metals and an acid electrolyte (potatoes contain acid, if you tried the experiment with a lemon you'd have a much more efficient battery). Oxydo-reduction reactions take place on the electrodes, when one of the electrodes is completely oxydized or when the electrolyte gets used, you can ge no more power.

Biological batteries are quite different : some microorganisms have the ability to directly oxydize nutriments (to feed themselves) and electrons are generated in the process. When there is no more nutriments available, you just add more and you get more power. That's why it's called a fuel cell, you do not need to change the cell when it is used, you just need to add more fuel. It is also very interresting to be able to get power from what you'd otherwise throw away, like old vegetables or any organic matter.