This project was created by Andrew Leader (EE'13) and Stefania Samojlik (ME'13) from The Cooper Union for the Advancement in Science and Art.
Edited: 04-30-2013

We have developed an educational microbial fuel cell kit for high school students. The kit enables students to perform experiments that relate theory to measured results, illustrate the relationship between biology and engineering, and increase their interest in STEM fields. We are testing the kit in the classroom to refine directions for construction, a sample lesson plan, and a sample lab protocol. These materials are made available on the internet for public use.

Microbial fuel cells (or MFCs) are a type of fuel cell that uses the natural metabolic processes in microbes to convert chemical energy into electrical energy. The specific model used in this educational kit is the Saccharomyces cerevisiae/methylene blue anode and a potassium ferricyanide/oxygen cathode MFC with glucose as the fuel. These specific MFC reagents were chosen on their safety and availability in the classroom. The MSDS sheets for the reagents can be found here. The steps of the MFC processes are described in the figure and text below.

1. The microbe takes in fuel (glucose) and the mediator molecule (methylene blue, MB), and digests the glucose. During this process, an electron (e-) binds to the mediator molecule.
2. The microbe excretes the negatively-charged MB and a proton (H+) into the surrounding fluid.
3. An electron is transferred from MB to the anode.
4. MB is recycled.
5. The electron travels from the anode to the cathode across a load.
6. Meanwhile, a proton diffuses across the cation exchange membrane to the cathode chamber.
7. The proton, oxygen, electron and ferricyanide ([Fe(CN)6-]3+) react to form water. The ferricyanide is recycled.

For a more detailed explanation of the biological and chemical processes, see introduction_to_mfcs.pdf.

Each MFC consists of the following manufactured components:

• 2 end plates (drawing: endplate_drawing.pdf)
  
• 2 chambers (drawing: chamber_drawing_1.pdf)
  
• 4 rubber gaskets (drawing: gasket_drawing.pdf)
  
• 2 graphite electrodes
  
  

Other readily available components include:

• 4 threaded rods
  
• 8 wing nuts
  
• 1 cation exchange membrane
  
  

The full bill of materials can be found here: mfc_materials.pdf

The manufacturing instructions for the components can be found here : <insert pdf here>

anode solution cathode solution phosphate buffer solution

videos:

The lesson plan handout contains all teacher preparation material and student handouts for an introductory lesson on electricity and MFC experimentation. This lesson does not assume any prior knowledge of electricity.

lesson_plan_update.doc

This suggested lesson plan is suitable for students learning about electricity on a high school level. The experiment deals with impedance matching and power maximization within a nonlinear system such as the MFC. The following is a brief procedure and sample data from such an experiment:
power_maximization_procedure.pdf
sample_data.pdf

OLD STUFF:
Project Proposal: project_proposal.pdf
MFC Diagram: visio-mfc_diagram.pdf

MFC Prototype: mfc_prototype_solidworks_exploded_view.pdf
Interim Powerpoint Presentation: presentation_mfc.pdf
Fourth (and Final) Draft of Poster :fall_poster_ver4.pdf