Microbial Fuel Cell of Science!!!

64,535

540

104

Introduction: Microbial Fuel Cell of Science!!!

About: Bill Nye the Science guy is my Hero... that and Bear Grylls...would be cool if they combined to become Bear Nye the Wilderscience Guy using science and technology to drink his own pee.

Fuel cell that harvests electrons from the bacteria in mud! And ELECTRons mean ELECTRicity....you get me?

The cell also makes a great habitat for a beta fish... The bacteria decompose the fish poop adding to the cell's fuel and keeping the water clean!

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Get Some MUCK!

"MUCK" is actually the correct term for soil from Wetlands .... I LOVE WETLANDS!

Muck has all kinds of awesome bacteria, one of which is Geobacter, it produces electrons as part of its cellular digestion!

Step 2: Prepare the Proton Exchange Membrane

75g salt. 200ml water. 5 grams agar or gelatin. Bring to boil. Petri dish. Fridge. Done.

The bacteria produce hydrogen IONS (an ion is an atom that has lost electrons)...a hydrogen ATOM is nothing but a proton and an electron buzzing around it...its like if the Earth was a proton and the moon was an electron...take away the moon....er I mean the electron and all you are left with is a single PROTON aka  a hydrogen ION

The PEM as they say  allows protons through it  and recombine with oxygen and the electrons to form a circuit and H20 as a byproduct.


Step 3: Make Electrodes

PREPARE THE ANODE (-)

Cut up strips of window screen and fold them into a square.

Google how to make "char cloth"....normally its made by survivalists to act as tinder for fire making but the high carbon content will make the bacteria grow and exchange their electrons to the window screen wire! Wrap the screen around a thick mat of carbon cloth. You can also just strip the insulation off the black wire and wrap the copper inner wires around a thick mat of char cloth if you don't have window screen or alligator clips. 

PREPARE THE CATHODE (+)  

Strip the red wire's insulation back to expose the copper wire's "dendrites" or "feelers" as I like to call them. 



Step 4: Put It All Together

  • Fill the Beaker with MUCK and the anode (make sure the anode is covered on top and bottom)
  • Put the PEM gel mold on top
  • Fill up gently with water
  • Put cathode in water (half in half out..see pix)

BOOM! Electricity! After a few days you can watch the voltage increase as more bacteria grow on the anode!

Right now I'm experimenting with "charge pump circuits" to bring the voltage up from 500-600mv to 3 volts!

SCIENCE!!!!



Weekend Projects Contest

Participated in the
Weekend Projects Contest

3 People Made This Project!

Recommendations

  • Sculpting Challenge

    Sculpting Challenge
  • 3D Printed Contest

    3D Printed Contest
  • Motor Vehicle Contest

    Motor Vehicle Contest

104 Discussions

0
LavanyaU
LavanyaU

Reply 3 years ago

Sir how to glow led from mfc

0
CorneliusC1
CorneliusC1

Reply 4 years ago on Introduction

Increasing surface area of cathode may help. a metal plate with one side touches the water surface and the other expose to air.

0
merna tamer
merna tamer

2 years ago

I make Proton exchange membrane by gelatin but it fails but I don't know why can you tell me about another recipe to make it, please? or how to make a successful one?

0
bick1822
bick1822

Reply 3 months ago

The difference between activating them is important if you want to use
gelatin instead of agar. Gelatin is made of proteins and peptides and agar is a
polysaccharide.


Gelatin should not be boiled, because it breaks down. Agar needs 95 deg C to
dissolve, so usually it is simply boiled. This means, that if you are using
gelatin, follow the box instructions (3/4 boiling water to ¼ cold water).

0
haanshirin
haanshirin

Question 6 months ago

How would you measure the electrical output. What would you connect the voltmeter to?

0
haanshirin
haanshirin

Question 6 months ago on Step 4

How would you measure the electrical output. What would you connect the voltmeter to?

0
haanshirin
haanshirin

Question 6 months ago on Step 4

what is your materials list, and would the cathode be just a wire?

0
microsopegeek
microsopegeek

1 year ago

How do you store the energy made by the MFC?

0
justtesting
justtesting

Question 1 year ago

Could you please tell me how we know for sure that this is indeed microbes at work and not a galvanic cell formed by the metals used?

0
VesaB
VesaB

Question 1 year ago on Introduction

what if we dont want to put the water with the fish would we need to put something on top of the agar?

1
ohyouhere
ohyouhere

2 years ago

I quite like your take on the project. I just don't get the role of the PEM: Other projects don't use one, they just use a cylinder that is high enough to ensure anoxic conditions in the bottom. I guess the PEM helps keep the mud separated from the water, but if I don't want fish in the water and instead use plants, I could just top off the mud with some soil for the plants, or am I wrong? Also, are you worried about building a galvanic cell between the steel window mesh and the copper electrode? There is enough salt in the solution to drive a simple battery.

0
JonkT
JonkT

3 years ago

Good day

We have build single chamber fuel cells using stainless steel mesh as anodes and copper as cathode. We also used compost mixed with water instead of muck.

Begin voltage reading is very high and good but within a day it decreases and just keep on decreasing. What are we dong wrong

0
ohyouhere
ohyouhere

Reply 2 years ago

You build a galvanic cell. If your electrode materials are not identical, you will build a galvanic cell that just dissolves one of the two metals into the solution while creating a current. If you use metal for the cell, use the same metal on both ends to really only measure biological activity.

0
Hairyloon
Hairyloon

Reply 2 years ago

My first guess is that there is not very much that is readily digestible for the relevant bacteria in compost as compared to muck.
What we need to do is run some experiments on different feedstocks.

0
DEEJAY246
DEEJAY246

2 years ago

Why the little blue fish???

0
whitsona
whitsona

3 years ago

The saltiness has me concerned about using this with actual fish. Are you using a betta in this picture because they can stand the saltiness?

0
PranavR21
PranavR21

3 years ago

I am designing a project for camp students and I was wondering if I could reuse the anode for the projects. I am assuming a new char cloth needs to be used for every project, but can I reuse the window screen? And also what metal should the window screen be made out of? Thank you for your help!

0
whitsona
whitsona

3 years ago

How long is the barrier good for? Does the salt eventually get dispersed into the water?

0
rimbow46
rimbow46

3 years ago

waow cool! produce electricity and the fish can still life :)