NOVELTY - The method comprises disposing nanostructures having major axes onto a support surface, removing a film comprising nanostructures from the surface, aligning the nanostructures of the film such that the major axes of the aligned nanostructures are parallel to the plane of the film, positioning the film atop a first surface, affixing the first surface to a second surface to form an interface between the first and second surfaces, cleaning the film before aligning the removed nanostructures, and placing a pressure sheet between a roller and the film.    USE - The method is useful for fabricating a composite material, which is useful in a composite article, a nanostructure film and a fuel cell (all claimed).    ADVANTAGE - The method is capable of efficiently fabricating the composite material with improved flexural strength, physical, chemical and mechanical properties including stiffness, strain, toughness, dynamic-fatigue, impact and damping and electrical and thermal properties thus improving thermal conductivity of the composite article, reducing coefficient of thermal expansion of the composite article, improving shielding of electromagnetic interference and enhancing the operation of diffusion member at given humidity level, electrical conductivity and peak power density of the diffusion member and performance of the fuel cell.    DETAILED DESCRIPTION - The method comprises disposing nanostructures having major axes onto a support surface, removing a film comprising nanostructures from the surface, aligning the nanostructures of the film such that the major axes of the aligned nanostructures are parallel to the plane of the film, positioning the film atop a first surface, affixing the first surface to a second surface to form an interface between the first and second surfaces, cleaning the film before aligning the removed nanostructures, and placing a pressure sheet between a roller and the film. The interface comprises the film of nanostructures. The nanostructure comprises a carbon nanotube, a nanosheet and/or a nanofiber, and has a characteristic dimension of 1-100nm. The film defines a thickness of 20-100 micrometers. The carbon nanotube comprises a single wall carbon nanotube or a multiwall carbon nanotube. The disposing step comprises growing the nanostructures, and growing carbon nanotubes atop a template surface by applying a carbon-containing fluid on the surface. The support surface comprises a catalyst. The removing step comprises application of hydrofluoric acid, and/or a phosphoric acid. The aligning step comprises application of mechanical force by the roller. A protective sheet is disposed adjacent to a surface of the film during the application of mechanical force, and is removed before affixing the first surface to the second surface. The affixing step comprises application of pressure, and/or curing a polymer present at the interface. The first and second surfaces comprise a fiber, a prepreg, a weave, triaxial, tow, tape, mat, and/or a braid. INDEPENDENT CLAIMS are included for:    (1) a method of fabricating a composite article;    (2) a method of fabricating a nanostructure film;    (3) a reinforcement material;    (4) a diffusion membrane/layer;    (5) a method of fabricating a diffusion layer; and    (6) a fuel cell.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a developmental chart for hierarchical nanocomposites.