Indoor Moss Microbial Fuel Cell

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Introduction: Indoor Moss Microbial Fuel Cell

I have been studying electrochemistry for some years and one day, I discovered something fascinating. I read a paper that showed that plants could be used to generate electrical power. Now, the mechanism behind how it works is a bit complex and some knowledge in chemistry is needed. Organic oxidation and reduction of bacteria cause potential differences and stores energy, just like capacitors. If you want to know more about the chemical process look at https://royalsocietypublishing.org/doi/full/10.10....

The thing is, making these plant fuel cells are crazy simple! So I am here to show you how to make your plant fuel cell. The research uses moss, which blew my mind off first because these plants don't have roots!

Step 1: Get Some Moss!

First, you need some moss. I live near a creek, so it was easy for me to get some samples. If you live in a city or places where there is no excess to natural moss, Amazon sells preserved moss. You might be asking what type of moss should you get. I don't know! But that is where the potential of this project comes from. Many people can experiment with mosses from their region to determine which types of moss are best for the fuel cells. I am pretty sure my samples are feather moss. If you get your moss from outside, make sure you wash them several times.

Step 2: Step by Step

Second, you need the materials. Now, compare to other projects, the things needed for this project are a bit foreign, but not too expensive. You will use carbon or graphite felt (carbon felt is cheaper) for the anode of the cell. For the cathode, you will need aluminum foil. The fuel cell needs dielectric and I am using zeolite powder, which is usually used for cosmetics. So the two weird materials are carbon felt and zeolite powder.

Step 1: Get or make a box for storing all the components. The bottom needs small holes. Make sure the height of the box is at least 2 cm. I had some 3d printed scraps around the house, so that explains the many tape marks on the box.

Step 2: Cut an aluminum foil that matches the size of the box and place it on the bottom. If the aluminum foil is creeping up the wall, duct tape it so it won't touch the anode in the future.

Step 3: Get one cable and tape it on the aluminum. I used copper tape, so the top side would also be conductive.

Step 4: Place the zeolite powder on top of the aluminum foil. I used 1.5 ounces to cover up a 12 cm x 12 cm squared box. The height of the zeolite volume was about 0.6 cm.

Step 5: Place the carbon or graphite felt on top of the powder. Make sure that the aluminum foil does not contact the graphite felt! Also, place a wire on top of the felt. Make sure you don't place the wire at the bottom.

Step 6: Get some soil from the backyard and moisture it. The height of the covering soil was about 0.3 cm. Next, place the moss on top of the moisturized soil and pressure it gently.

Step 3: Done!

That is it! It's almost like making a sandwich. Now the experimentation is all upon you. Change the moss breed, sunlight, humidity to see the changes in voltage. It's like taking care of plants but you will get numbered output based on the performance. How cool is that?

Step 4: My Build

Don't expect too much from the fuel cell. Remember, it is just moss. From the 0.0144 meters squared area of moss, I have been getting about 0.8 V with fluorescent light. This resulting power output is in the range entering milliwatt (mW). But I think there are potentials of this technology in building rooftops. Imagine harvesting energy from the garden instead of solar panels!

Thanks for viewing - Brayden Noh

Step 5: Video of the Fuel Cell Charging

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    25 Comments

    0
    kevin413
    kevin413

    Question 4 months ago

    Hi! measured the voltage without the moss and soil planted and got a read of around 0.9V. What might be an explanation for this?

    0
    JosephU10
    JosephU10

    Answer 4 weeks ago

    An analogy that I hope is helpful and not too long winded.

    If you imagine walking out of a store on a hot day and the air rushing against your face is a combination of the difference in temperature. The bigger the difference in the temperature the faster the air potential tries to make up the hap. The more dense the air the easier it is to both feel and combined with the speed of the air trying to fill the temperature gap becomes the force that you can feel.

    In this case you are measuring voltage which is similar to the temperature difference. The difference in the electrical charge provides that sort of gap that wants to be filled. But you not only need the voltage difference (i.e. difference in temperature) to be useful you also need the amperage (i.e. Air density) to produce some actual that you can measure as watts (i.e. pushing force).

    For your case I think what you were measuring was mostly the difference in potential voltage between the graphite and the aluminum. But the amps are likely at a trickle and not useful to actually power something. To get the amps to flow you need to be moving charge between the two areas and for that the bio processes mentioned help. So with the moss, soil, moisture, light etc... you probably would measure more amps.

    You get watts of power by multiplying the Amps and the Voltage together.

    Its kind of like having an upside down 2 liter water bottle with a tiny bit of water left on the sides. The potential angle is the same (i.e. voltage) but your not going to be able to move a water wheel unless you have a decent amount of water (i.e. amps) moving from the top of the bottle out the spout. The bio processes kind of generate that preverbal water that can flow out that bottle.

    0
    ludwigtiston
    ludwigtiston

    Question 6 months ago

    What kind of zeolite is required for this, online I find zeolite for aquarium purification and as a dietary supplement and such. Does this: https://www.heiltropfen.de/shop/en/home/18-zeolite... work for example?
    Also, what other materials work for this, that is to say; what qualities of the zeolite are we looking for here? Very interesting project I must say!

    0
    MsJenfaM
    MsJenfaM

    7 months ago on Step 5

    I'm a classroom teacher interested in doing this with my students. I read all the replies but some people didn't get it to work. Does it for sure work??? What about water? Can you use other plants?

    0
    braydennoh
    braydennoh

    Reply 7 months ago

    Zeolite might be too expensive for classroom uses. I would rather recommend doing things with hydrogen fuel cell or mud fuel cell.

    0
    MsJenfaM
    MsJenfaM

    Reply 7 months ago

    Hm, sounds cool. I don't live in the US...

    0
    Megan_Gill
    Megan_Gill

    Question 7 months ago

    Thank you for this Instructable! It is really interesting. I have attempted to build a couple of these but am not getting any voltage. Does the zeolite clay have to be moistened or kept dry? Thank you.

    0
    jazminekimchi
    jazminekimchi

    Question 9 months ago

    omg this is literally insaaaaane !!!! can i ask if does seaweed works just fine as an alternative to moss ?

    0
    JacenF
    JacenF

    10 months ago

    How much did it cost?

    2
    bronyeg
    bronyeg

    1 year ago

    Hey, you should go to mars someday, but just scratching my head for answers what does the moss do exactly, I'm kinda confused on this and i am hoping to make a larger one to maybe power a bunch of LEDs for a fun demonstration, and I need to sound nerdy. :-D to live up to my name.

    0
    ThLinn
    ThLinn

    1 year ago on Step 4

    Id like to know if you have ever herd of batch Bio digesters and if so have you ever tried to build one? there have been some built by farmers in the US but they use tanks that are far from the optimal design. The Japans have been building a sqaushed ball tank version for many years that is a true God send in all its benifits. Much of which comes from the symple changing of the shape of the tanks.

    0
    xacted
    xacted

    Question 1 year ago on Step 4

    This is a fantastic project and renewable energy,,, i'd like to understand more though. What is that little machine you have it plugged in to? Can i store the energy? or use it to fuel lights, say an indoor garden grow lights? And how do i do that... is that what you are doing, putting it into a battery?

    0
    braydennoh
    braydennoh

    Answer 1 year ago

    In the second video, I was discharging the fuel cell with a resistor. You can really think of this as a capacitor (even a supercap). It builds up voltage and discharges almost linearly when there is a load. I wouldn't use this for lighting as it will take up large area to get sufficient power; rather an educational purpose for electrochemistry and redox reaction.

    0
    zebe1
    zebe1

    Reply 1 year ago

    Amazing project. I wonder why we do not have electro-moss roofs yet.
    What was the resistance of the resistor? How many Ohms?

    0
    braydennoh
    braydennoh

    Reply 1 year ago

    Sorry for the late reply. The resistor's value was 220k.

    0
    zebe1
    zebe1

    Reply 1 year ago

    P=0.8^2/220000 =2.9microW. That is 0.2miliW per square meter. Or am I wrong?

    1
    xacted
    xacted

    Reply 1 year ago

    Thanks braydennoh for your great project and answering me. I'm a horticulturalist and I've recently been doing a lot of pot planting, propagating and creating moss landscapes during covid19 isolation. I was fascinated to think that the moss in my outdoor pots could potentially power light in my propagation tank indoors or night lights. Anyway I'm a bit of a nerd and I loved it.

    0
    jonwatson83
    jonwatson83

    Question 1 year ago

    This is an awesome idea...I am putting together a community project in our village and wondered if i can referrence some of your details for our plans?