Air-breathing microfluidic fuel cell with fuel reservoir

This paper describes the design and characterization of an air-breathing microfluidic fuel cell with a stationary fuel reservoir above the anode replacing the continuous fuel stream. Unlike other air-breathing microfluidic designs, the fuel is not in direct contact with electrolyte stream allowing the use of high fuel concentration. In addition, Ohmic losses are minimal because of the low anode-to-cathode spacing. Since the fuel passes through the catalyst layer of the anode, the conventional depletion boundary layer does not form. Improved mass transport compared to previous microfluidic designs is obtained because of a supply of a uniform fuel concentration over the anode and efficient bubble removal from the anode active sites. For practical applications, the fuel reservoir can be replaced by a pressurized fuel cartridge. The pressure is optimized according to the fuel concentration and the power density. This simple design of the fuel cell provides a low-cost but functional platform for practical applications. (C) 2012 Elsevier B.V. All rights reserved.