NOVELTY - Manufacturing fuel cell involves contacting a separator plate (14, 16) with a gas diffusion media (34, 36, 38, 40) to form a covered reactant gas flow field. The separator plate includes several lands that define several channels having a surface; and the gas diffusion media includes a first surface region that contacts the lands of the separator plate and a second surface region complementary to the channels of the separator plate, where at least a portion of the surface of the channels of the separator plate and/or the second surface region of the gas diffusion media is microtextured.    USE - For manufacturing a fuel cell (claimed), useful as power source to supply electrical energy for automobiles and other industrial applications.    ADVANTAGE - The method provides balanced hydration of the proton exchange membrane, better transport of water to cool the fuel cell to prevent overheating, equilibration or reduction of local moisture gradients, and prevents flooding or saturation with liquid water.    DETAILED DESCRIPTION - Manufacturing fuel cell involves contacting a separator plate (14, 16) with a gas diffusion media (34, 36, 38, 40) to form a covered reactant gas flow field. The separator plate includes several lands that define several channels having a surface; and the gas diffusion media includes a first surface region that contacts the lands of the separator plate and a second surface region complementary to the channels of the separator plate, where at least a portion of the surface of the channels of the separator plate and/or the second surface region of the gas diffusion media is microtextured by a process involving focusing laser pulses to selectively ablate surface material producing microtexturing comprising several projections of surface material, where the surface material comprises surface of several channels of the separator plate and/or the second surface region of the gas diffusion media; and pressing a microtextured stamping plate onto the surface of channels of the separator plate. The microtextured stamping plate is formed by focusing laser pulses to selectively ablate surface material of the stamping plate producing microtexturing comprising several projections of surface material on the stamping plate; or multilevel roughness including projections and depressions about 0.1-10 micrometers in height, length, and width. An INDEPENDENT CLAIM is included for a fuel cell comprising a separator plate including several lands that define several channels having a surface to form a reactant gas flow field; and a gas diffusion media including a first surface region complementary to lands of the separator plate and a second surface region complementary to the channels of the separator plate. The lands of the separator plate contacts the first surface region of the gas diffusion media to form a covered reactant gas flow field.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of two membrane electrode assemblies (MEAs) in a liquid-cooled proton exchange membrane (PEM) fuel cell stack.    Stack (2)    Bipolar plate (8)    Terminal collector plates (10, 12)    Separator plates (14, 16)    Diffusion media. (34, 36, 38, 40)