Acidic methanol solutions have been investigated for use in direct methanol microchannel fuel cells. The increased proton conductivity of a methanol solution containing sulfuric acid enables the anode to be constructed with the catalyst separated from the proton exchange membrane. This approach could be especially useful in the fabrication of thin-film microchannel fuel cells where a more complex carbon fabric electrode is not possible. The performance of sequential build-up fuel cells was shown to be improved by depositing an additional layer of Pt/Ru on the side-walls of the anode microchannels opposite the membrane. Results from anode half-cell and full cell experiments are reported. (C) 2004 Elsevier B.V. All rights reserved.