Miniature Fuel Cells.
Miniature fuel cells operating on chemical fuels that would not require replenishment of reactants are needed for implantable energy sources. One type, the microbial fuel cell, has been too bulky and incompatible for implants. A miniaturized microbial fuel cell generating electrical power from the metabolism of microbes such as baker's yeast using glucose and oxygen has been developed. Glucose and oxygen are the only substances required to fuel this cell and are readily available in typical biological environments. The only waste products are carbon dioxide and water. These fuel cells could be power sources for implantable biomedical devices, including sensors and stimulators. Microfabrication is used to miniaturize the structure. Electrodes facilitate electron transfer and power production. The microbial fuel cell extracts glucose and other metabolites from body fluids and is a renewable, long-term power source for implantable biomedical devices. In the anode compartment, one or more yeast cells are used as the catalyst in a buffer solution with the nutrient or fuel for the fuel cell. The electron transfer to the anode is facilitated with an electron transfer mediator such as methylene blue, methyl viologen, or other viologen dyes. The cathode compartment contains oxidizing materials for accepting electrons from the cathode, thereby becoming reduced. Ferricyanide is such a material. Ferrocyanide in the presence of oxygen and protons can be oxidized to regenerate ferricyanide and produce water as the by-product. The fuel cell can be made biocompatible by encapsulating with polysaccharides, porous silicon, or polytetrafluoroethylene. Thirty-nanometer-diameter fluid ports or permeable membranes transfer the fuel and waste products. The Baker's yeast (Saccharomyces cerevisiae) is used as the power-producing microbe.
Roger D. Corneliussen is Professor Emeritus of Materials Engineering, Drexel University, in Philadelphia, Pennsylvania, USA. He is editor of Maro Polymer Alerts and the Maro Polymer website (www.maropolymeronline.com). He has been active in SPE since 1962 and has served on the board of the Philadelphia Section and as SPE Councilor. For Maro Patent Alerts he reviews all U.S. Patents weekly, makes links to the polymer-related patents, and sends the links daily to subscribers. These patent abstracts are based on the weekly selection process. To sample Maro Patent Alerts, email a request to email@example.com.
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|Title Annotation:||industry PATENTS|
|Date:||Mar 1, 2007|
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