Microbial Fuel Cells
Microbes can be used to provide fuel for the fuel cells. (RDC 12/27/2010)
“The process uses bacteria, living in biofilms on the special anode, to break down the organics, separating electrons from protons. These electrons and protons then travel to the cathode, the former via an external wire, the latter by diffusing through the electrolyte which is generally a substance that does not conduct electricity readily. In the electricity-generating microbial fuel cells, the protons and electrons combine at the cathode with oxygen to form water. This consumption of the electrons allows more electrons to keep flowing from the anode to the cathode as long as there is a source of chemical bonds (i.e. organic waste) to fuel the reaction.”
(Swift, Butler and Wallace of Zerox, US Patent 7.807,303, 10/5/2010)
Recent US Patents
10/5/2010
7,807,303
Microbial fuel cell and method
Swift, Butler and Wallace of Xerox, Connecticut have developed a fuel cell consisting of a cell with two chambers. The first chamber contains a fluid including a biomass with the microbes and an anode. The second chamber contains an oxygenated fluid and a cathode. The anode consists of mass of aligned fibers. (RDC 12/21/2010)
Recent Journal Articles
1/21/2011
Three-Dimensional Carbon Nanotube−Textile Anode for High-Performance Microbial Fuel Cells
(291–296) Nano Letters 11 #1 (2011)
Xie et al of Stanford University, California and Universita degli Studi di Milano, Italy developed a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube−textile (CNT−textile) composite for high-performance microbial fuel cells. The macroscale porous structure of the intertwined CNT−textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte−biofilm−anode interfacial area than the projective surface area of the CNT−textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT−textile anode. An MFC equipped with a CNT−textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater. (RDC 1/21/2011)