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
Participated in the
Indoor Plants Challenge