NOVELTY - A diffusion layer for a direct oxidation fuel cell having a protonically conductive membrane (7) comprises a substrate (44) including carbon and being coated with an electrically conductive layer that forms a microporous layer (48) on the substrate. The microporous layer has indented channels providing preferential flow paths to cause liquids to travel in predetermined directions in the fuel cell.    USE - For a direct oxidation fuel cell (claimed) e.g. direct methanol fuel cell.    ADVANTAGE - The diffusion layer eliminates or minimizes flooding of the cathode diffusion layer area, which is a performance-limiting condition in direct methanol fuel cells.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a membrane electrode assembly comprising a protonically conductive, electronically non-conductive membrane; diffusion layer(s) (10); and a catalyst (30) on the membrane and forming an active area of the assembly;    (2) a direct oxidation fuel cell comprising a protonically conductive, electronically non-conductive membrane electrolyte having an anode face and an opposing cathode face (11); an anodic diffusion layer disposed in intimate contact with the anode face of the membrane electrode assembly which allows the associated fuel mixture to pass through to the anode face as fuel is consumed at the anode and which also allows anodically generated carbon dioxide (CO2) to be transported away from the anode face of the membrane; a cathodic diffusion layer dispose din intimate contact with the cathode face of the membrane electrode assembly and which allows oxygen to pass through to the cathode face of the membrane electrode assembly, wherein the cathodic diffusion layer comprises a carbon-containing substrate and a microporous layer having channels to provide preferential flow paths such that liquid reactants and byproducts in the fuel cell travel in predetermined directions along the channels; and collector for electric current generated in the electricity-generating reactions to provide the electric current to a load;    (3) a direct oxidation fuel cell system comprising a direct oxidation fuel cell; a fuel source; a fuel container and delivery assembly coupled between the fuel source and the direct oxidation fuel cell; mechanism for removing reactants from the fuel cell; mechanism for removing by-products from the membrane electrode assembly; and electrical coupling for connecting the fuel cell with an external device to which it is providing power; and    (4) a method of fabricating a liquid-removing diffusion layer for a protonically conductive membrane used in a direct oxidation fuel cell comprising providing a carbon substrate; treating the substrate by coating it with a microporous layer of material that is electrically conductive, hydrophobic and permeable to gases; and forming channels in the microporous layer.    DESCRIPTION OF DRAWING(S) - The figure shows a direct oxidation fuel cell system using the diffusion layer.    Protonically conductive membrane (7)    Diffusion layer (10)    Cathode face (11)    Catalyst (30)    Substrate (44)    Microporous layer (48)