NOVELTY - Formation of nanostructures or nanomaterials comprising providing a thermal control barrier on a substrate and forming the nanostructures or nanomaterials, is new.    USE - The method is for formation of nanostructures or nanomaterials, where nanostructures are carbon nanotubes or carbon nanowires formed by plasma enhanced chemical vapor deposition using carbon containing gas plasma (claimed). Nanostructures include all metallic, semiconducting, and insulating nanostructures, which have high aspect ratio such as single-walled and multi-walled carbon nanotubes, carbon nanofibers, carbon nanofilaments, carbon nanoropes (ropes of carbon nanotubes), silicon and silicon oxide nanowire, gallium nitride nanowires, and zinc oxide nanowire useful for, e.g. interconnects used in microelectronics or integrated circuits for carrying large current densities, electrodes, sensors (i.e. mechanical or chemical), and nano-scale lasers. The nanotube is used to detect viruses, antibodies, or gases; for harvesting of energy via the surrounding environment in chemical batteries, or harvesting of solar energy; and to transmit radio frequency signals. It acts as miniature bio-potential sensors in e.g. electrocardiogram devices.    ADVANTAGE - The method deposits nanostructures or nanomaterials onto substrates at low temperatures, while maintaining low defect levels; provides an increase in the commercial potential of carbon nanotube production, especially where nanostructures or nanomaterials are applied to commercially significant materials that could not be used with the known high temperature methods of deposition; and allows a higher yield and throughput in the synthesis of nanostructures due to increased growth rates. The use of thermal barrier layer allows large area deposition of nanotubes, which effectively increases the efficiency of the sensor.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) an assembly or structure for forming nanostructures or nanomaterials comprising a substrate and a thermal control barrier; and    (2) an apparatus for forming nanostructures or nanomaterials, comprising a plasma chamber, heat source(s), and a chuck for mounting a substrate, where chuck is interchangeable.    DESCRIPTION OF DRAWING(S) - The figures are a schematic illustration of the nickel catalyst on a titanium thermal barrier layer, and a graph of the simulation of the temperature containment effect of the thermal barrier as an effect of barrier thickness.