Independent Study in Development of a Bacterial Fuel-Cell

A project to develop a practical operational bacterial fuel-cell has been underway for the past three school years and run as an independent study. The project is interdisciplinary where students in biology, physics, chemistry, engineering and sustainability have been and are involved. The intent is to use waste water to generate sufficient electrical energy to charge a battery bank for subsequent use for lighting and other devices. The purpose is to develop a practical design that can be used in manure ponds, cesspools or water-treatment plants, and perhaps be applicable to underdeveloped areas. To date, laboratory tests on three prototypes have been conducted using E. coli bacteria in a laurel-tryptose broth. The designs have employed i) carbon-cloth anode and cathode, ii) carbon-tube anode with copper-screen cathode and iii) carbon brush anode with copper-screen cathode (currently under fabrication). In all cases, the cathode is exposed to open air via a Nafion exchange membrane.

The project is used for both independent study as well as experiential credit. Group meetings are held weekly whereby results, design plans and experimental scheduling are reviewed and discussed. Students are subdivided into working groups that include design & fabrication of a particular concept, followed by laboratory testing & data acquisition. Data includes continuous measurement of voltage and current as well as periodic analysis of bacterial-concentration count during the test period. Emphasis of the project is on determining and demonstrating a design that can be scaled for practical production of usable electrical power with the goal of applying a working device to an underdeveloped area. Application for grant funding is currently in process. As this is an ongoing project, the paper will include results to date. The conference presentation will be made by students.