Bio-photovoltaic Panel
Farmer John
Harness the power of moss and grass to generate electricity for everyday use.
Believed to be based off fuel cell mechanics, though this is to be determined in subsequent tests. It can be used to recharge phones, light up LEDs, and power a microwave.
Farmer John
Here is the link to the moss bio-photovoltaic example I showed some of you this evening.
Mike Horwath:
Thanks for the responses! The bio-photovoltaic article did have some issues, but I'm willing to accept the system could work if electronics issues are fixed. It would have been nice if they had a better explanation of the chemistry/biochemistry involved, although I was able to find some other articles about bio-photovoltaics floating around.
I'm curious now about "digifab-ing substrate to grow mycelium." Could you share info or a link about this process?
Farmer John:
Bio-chem:
From my understanding, the cano-bacteria capture the nitrogen from the surrounding air along with water and nutrients(co-factors) from the plant roots (symbolic). The water + N2 become NOx's and free H+'s, which are released into the soil along with electrons. So in the future, ideally we would want some sorta high nitrogen consuming plant.
Fuel Cell Chemistry comes from:
1) the H2 (ionized) gradient - since the roots would have a surplus of localized hydrogens
2) the capture (reduction) of oxygen like a normal fuel cell
The soil acts has a proton transport / membrane for the free hydrogens - however is a poor conductor for electrons which "choose" the path going through the electrodes generating the current.
I can say with confidence the circuit will work, and seems easily enough to do in a week's time (for a meet up in two weeks)
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PS:
@Katie, sounds great! So what do you have in terms of things you can bring? I have dirt, tree moss, leds, if you can handle the draft, keep it simple - keep it fun, I just need a list of recommend materials.
@mike, this would best be done as a sub forum on the forum group
Katie:
I can get more details from them on their specific experiences with the chemistry/biochemistry. Getting electricity out of these things is rather simple, whether it's fruit, rooted plants, algae, yeast, or even just salt water. Optimizing the process, and making a system that is efficient and condensed enough to be really useful, is of course much harder.
Mike Horwath:
Thanks Katie! That mycelia project looks very nice. I enjoyed taking a look at Phil Ross's stuff too. If I tried something along these lines myself, I would probably use the "spent grains" left over from homebrewing.
Getting electricity out of the bio-voltaic system may not be quite as easy as a fruit or seawater battery. Those usually work by having electrodes of 2 different metals, such as zinc and copper. The energy comes from oxidation of the cathode and reduction of H+ to H2 at the anode, so for example the zinc cathode gets slowly dissolved into Zn2+. The goal for the bio-photovoltaic seems different, with energy coming some catabolic process in the bacteria that releases electrons to the cathode. Or at least releases some soluble electron carrier that can diffuse to the cathode. Maybe this will be easy, I don't have the experience to really know..
Looks like I got "anode" and "cathode" mixed up in my older post. Ugh..its been awhile since I learned this stuff. Apologies.
I've been checking out Mudwatt: http://www.keegotech.com/
I think this is essentially the same principle as the bio-photovoltaic, except that there are no plants replenishing the nutrients.
Katie:
In my experience, it's pretty simple using copper and galvanized steel to extract energy from these reactions in the soil. Again, optimizing is certainly much more difficult. You do, however, need quite a large amount of surface area on anode and cathode coils in order to get anything really productive. Also, the soil needs to be kept almost saturated.
It's easier to get energy from algae reactions. For this, I use graphite. However, personally, since I'm currently working on an algae energy project for work, my contract does not allow me to work on an outside algae one. (Not that this should stop anyone else from doing one, of course.)
Anyway, I've achieved lighting leds with soil before (in cursory tests), so we shouldn't have any trouble getting a demo up for the forthcoming meeting.
I'm in Chicago for work until Sunday. John, maybe we can get started on the demo on Monday evening? We can both bring whatever supplies we have around? It would be great if you have soil! I can bring container designs with me right away.
On another note, I've located a couple of Biological labs in the fablab network, including one in France that is education/research based and somewhat attached to a university. Perhaps we might want to reach out to some of these fab bio labs to share experiences, conversations, etc.
(Ps. I'll make a circuit diagram and block diagram tonight for us to start with)
Mike Horwath:
Galvanized steel is zinc-coated, so I think in that setup your power is still coming from oxidation of zinc rather than a biological process.
I can imagine the surface area does make a big difference to get any reasonable amount of current!
John:
I happen to be an expert in FC's believe it or not, so let me clear-up what I meant by my observations earlier, without trying to sound like a total smart ass until we get one up and running.
Based on the data provided:
1) The coil setup provided higher voltage than the plate indicating SA doesn't play as big a role. Instead I see it as a higher reactant gradient.
2) Though hard to conclude, it appears the data-artist specifically drew the electrodes one above the other, indicating a soil depth dependency; rather than side-by-side like that of galvanics.
The main difference between galvanics and FCs is, galvanics depend on electrode types, FCs depend on concentration gradients. There's a few other things I would like to say cause I really want to get this project going, but most of it is proprietary data. When we do get one up and going (with katie's help), we can simply test this by sticking in 2 copper coils as electrodes (as long as the two electrodes are the same metal, galvanics fail) and see what happens.
Mike Horwath:
Using 2 copper electrodes would certainly be enough to convince me that the energy is not coming from a galvanic process :)
My understanding from the bits I've read in the last 2 days is that the positioning of the electrodes is needed to keep one electrode deep in the soil in a low-oxygen environment.
Anyway, I hope I'm wrong and this project is easy to get working. I think I'm a bit "weathered" from my experience with biological systems, things always seem to take more trial and error than expected.