NOVELTY - A membrane electrode assembly (MEA) comprises an anode and a cathode and a proton conductive membrane between them, the anode and the cathode each comprising a patterned sheet of longitudinally aligned transition metal-containing carbon nanotubes, where a catalytically active transition metal is incorporated throughout the nanotubes.    USE - The MEA is used in PEMFC.    ADVANTAGE - The present invention provides a new method of preparing an MEA for a PEMFC that reduces precious metal usage, which eliminates the need for gas distribution electrode (GDE) and simplifies the design and fabrication of bipolar plates. The method consists of multiple steps including growing template-free aligned carbon nanotubes, transferring directionally aligned nanotubes onto the surface of a polymer electrolyte, and fabricating a fuel cell with flow field-free bipolar plates. This new method also leads to a new PEMFC design in which either or both anode and cathode are made of aligned carbon nanotubes with a portion of the nanotubes embedded in a proton conduction polymer and another portion exposed to reactant gas flow contacting the bipolar plates directly. The aligned nanotubes can also be built optionally with a pre-designed flow field pattern. MEA design eliminates the need for GDE and the necessity of embossing flow fields on the surface of bipolar plates.    DETAILED DESCRIPTION - An MEA comprises an anode and a cathode and a proton conductive membrane between them, the anode and the cathode each comprising a patterned sheet of longitudinally aligned transition metal-containing carbon nanotubes, where the carbon nanotubes are in contact with and are aligned generally perpendicular to the membrane, where a catalytically active transition metal is incorporated throughout the nanotubes; and where the MEA is produced by: forming a sheet of longitudinally aligned graphitic nanotubes on a substrate including a three dimensional pattern for aligning the nanotubes in a gas-flow pattern by chemical vapor deposition (CVD), and transferring the so-formed sheet of nanotubes to a surface of a proton conductive membrane, where the chemical vapor deposition comprises pyrolysis of a transition metal-containing organometallic material to form nanotubes that include the transition metal within the nanotube structure. An INDEPENDENT CLAIM is a membrane for a proton exchange membrane fuel cell (PEMFC) comprising a proton conductive membrane that includes longitudinally aligned graphitic nanotubes generally perpendicular to the proton exchange membrane and in contact with its surface, a catalytically active transition metal being incorporated within the nanotubes.