Low Cost Environmentally Benign Porous Paper Based Fuel Cells for Micro-Nano Systems

This work deals with the development of a paper based fuel cell for application in micro-nano systems. In this cell, a porous paper serves as a transport medium and eliminates the need for any metering devices that are integral to conventional fuel cells. Since only very small flow rates of reagents can be achieved on paper, these cells produce only a few milli-watts of power. In this work, formic acid is used as the fuel and potassium permanganate is used as the oxidant. Since the cell presented here is membraneless, both formic acid and potassium permanganate are mixed with sulfuric acid, and they form the anolyte and the catholyte, respectively. A special cell geometry has been designed and implemented to minimize and delay the fuel and oxidant cross over effects. In order to keep the cost low, graphite sheets without any metal loading are used as the current collectors. Two variants of filter paper are used for implementing the fuel cells. Cell characterization is accomplished by performing detailed potentiometric and impedance studies. Our study on formic acid cell shows that the porous paper cell architecture can be extended to other fuel-oxidant combinations as well.