Browsing by Author "Nicholas, Nolan Walker"

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Carbon nanotube diameter selection by pretreatment of metal catalysts on surfaces
    (2012-02-28) Hauge, Robert H.; Xu, Ya-Qiong; Shan, Hongwei; Nicholas, Nolan Walker; Kim, Myung Jong; Schmidt, Howard K.; Kittrell, Carter W.; Rice University; United States Patent and Trademark Office
    A new and useful nanotube growth substrate conditioning processes is herein disclosed that allows the growth of vertical arrays of carbon nanotubes where the average diameter of the nanotubes can be selected and/or controlled as compared to the prior art.
  • Thumbnail Image
    Item
    Electrical device fabrication from nanotube formations
    (2013-03-12) Nicholas, Nolan Walker; Kittrell, Carter W.; Kim, Myung Jong; Schmidt, Howard K.; Rice University; United States Patent and Trademark Office
    A method for forming nanotube electrical devices, arrays of nanotube electrical devices, and device structures and arrays of device structures formed by the methods. Various methods of the present invention allow creation of semiconducting and/or conducting devices from readily grown SWNT carpets rather than requiring the preparation of a patterned growth channel and takes advantage of the self-controlling nature of these carpet heights to ensure a known and controlled channel length for reliable electronic properties as compared to the prior methods.
  • Thumbnail Image
    Item
    Embedded arrays of vertically aligned carbon nanotube carpets and methods for making them
    (2015-06-30) Kim, Myung Jong; Nicholas, Nolan Walker; Kittrell, Carter W.; Schmidt, Howard K.; Rice University; United States Patent and Trademark Office
    According to some embodiments, the present invention provides a system and method for supporting a carbon nanotube array that involve an entangled carbon nanotube mat integral with the array, where the mat is embedded in an embedding material. The embedding material may be depositable on a carbon nanotube. A depositable material may be metallic or nonmetallic. The embedding material may be an adhesive material. The adhesive material may optionally be mixed with a metal powder. The embedding material may be supported by a substrate or self-supportive. The embedding material may be conductive or nonconductive. The system and method provide superior mechanical and, when applicable, electrical, contact between the carbon nanotubes in the array and the embedding material. The optional use of a conductive material for the embedding material provides a mechanism useful for integration of carbon nanotube arrays into electronic devices.
  • Thumbnail Image
    Item
    On the fabrication and utilization of vertically aligned single walled carbon nanotube structures
    (2009) Nicholas, Nolan Walker; Hauge, Robert H.
    The inherent alignment in carbon nanotube "carpet" structures makes possible a variety of applications particularly for electronic device implementation. A method has been developed for transferring a carpet to a conductive substrate, to enable implementation for electronic devices. Methods for manipulating the size of the nanoparticle growth catalyst through controlled acid etch and for creating highly dense structures of aligned nanotubes from carpets by liquid processing are presented. One of the most promising, near-term applications for nanotube carpets is as the basis for a solid-state, ultra-high energy/ultra-high power "supercapacitor." Modeling of capacitance characteristics, fabrication methods and electrical characterization data are presented.
  • Thumbnail Image
    Item
    Templated growth of graphene: A novel method for efficient graphene synthesis
    (2006) Nicholas, Nolan Walker; Hauge, Robert H.; Smalley, Richard E.
    A novel templated growth process for graphene structures is proposed and demonstrated. Extended, pristine sheets of graphene can be synthesized by additively reacting carbon into a pre-existing graphene sheet which is on a templating substrate through a CVD type process termed "van der Waals templating". Finding a technologically viable synthesis method for planar graphene has recently become of significant interest with the recent recognition of its unusual electronic properties. Various morphological growth patterns such as "pacman" structures and rounded corners are observed which elucidate interesting features of this growth mechanism, linear sheet growths on the order of 150 nm have been produced.