US Patent 7868531 Carbon nanotube arrays for field electron emission

A method for preparation of carbon nanotubes (CNTs) bundles for use in field emission devices (FEDs) includes forming a plurality of carbon nanotubes on a substrate, contacting the carbon nanotubes with a polymer composition comprising a polymer and a solvent, and removing at least a portion of the solvent so as to form a solid composition from the carbon nanotubes and the polymer to form a carbon nanotube bundle having a base with a periphery, and an elevated central region where, along the periphery of the base, the carbon nanotubes slope toward the central region.