A nanoengineered membrane for controlling material transport (e.g., molecular transport) is disclosed. The membrane includes a substrate, a cover defining a material transport channel between the substrate and the cover, and a plurality of fibers positioned in the channel and connected to and extending away from a surface of the substrate. The fibers are aligned perpendicular to the surface of the substrate, and have a width of 100 nanometers or less. The diffusion limits for material transport are controlled by the separation of the fibers. In one embodiment, chemical derivatization of carbon fibers may be undertaken to further affect the diffusion limits or affect selective permeability or facilitated transport. For example, a coating can be applied to at least a portion of the fibers. In another embodiment, individually addressable carbon nanofibers can be integrated with the membrane to provide an electrical driving force for material transport.