Patents by Inventor Stephen L. Sass

Stephen L. Sass has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030228418
    Abstract: A replication technique is employed to reproduce substrates having periodic nanometer scale structures formed on a surface thereof. In the technique, a thin film of cellulose acetate is placed on top of a template substrate having the desired surface to be replicated. The cellulose acetate is softened, thereby taking on the configuration of the template surface. The film is peeled off, yielding a negative replica of the template surface on the underside of the film. A thin layer of suitable material, such as gold, platinum, iron or carbon, is then deposited on the underside of the film, thus resulting in formation of a replica substrate having the same periodic nanostructure characteristics as the original template.
    Type: Application
    Filed: March 6, 2003
    Publication date: December 11, 2003
    Inventors: Melissa A. Hines, Christopher K. Ober, Stephen L. Sass
  • Publication number: 20020102428
    Abstract: The periodic stress and strain fields produced by a pure twist grain boundary between two single crystals bonded together in the form of a bicrystal are used to fabricate a two-dimensional surface topography with controllable, nanometer-scale feature spacings (e.g., from 50 nanometers down to 1.5 nanometers). The spacing of the features is controlled by the misorientation angle used during crystal bonding. One of the crystals is selected to be thin, on the order of 5-100 nanometers. A buried periodic array of screw dislocations is formed at the twist grain boundary. To bring the buried periodicity to the surface, the thin single crystal is etched to reveal an array of raised elements, such as pyramids, that have nanometer-scale dimensions. The process can be employed with numerous materials, such as gold, silicon and sapphire. In addition, the process can be used with different materials for each crystal such that a periodic array of misfit dislocations is formed at the interface between the two crystals.
    Type: Application
    Filed: November 8, 2001
    Publication date: August 1, 2002
    Inventors: Stephen L. Sass, Christopher K. Ober, Yuri Suzuki
  • Patent number: 6329070
    Abstract: The periodic stress and strain fields produced by a pure twist grain boundary between two single crystals bonded together in the form of a bicrystal are used to fabricate a two-dimensional surface topography with controllable, nanometer-scale feature spacings (e.g., from 50 nanometers down to 1.5 nanometers). The spacing of the features is controlled by the misorientation angle used during crystal bonding. One of the crystals is selected to be thin, on the order of 5-100 nanometers. A buried periodic array of screw dislocations is formed at the twist grain boundary. To bring the buried periodicity to the surface, the thin single crystal is etched to reveal an array of raised elements, such as pyramids, that have nanometer-scale dimensions. The process can be employed with numerous materials, such as gold, silicon and sapphire. In addition, the process can be used with different materials for each crystal such that a periodic array of misfit dislocations is formed at the interface between the two crystals.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: December 11, 2001
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Stephen L. Sass, Christopher K. Ober, Yuri Suzuki
  • Patent number: 5240495
    Abstract: In situ formation of metal-ceramic oxide microstructures is carried out on a starting oxide phase containing at least a most noble metallic component (e.g., iron) and a least noble metallic component (e.g. manganese) and subjecting the starting oxide phase to a temperature and oxygen partial pressure and for a time period to cause reduction of only part of the most noble metallic component to elemental metal.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: August 31, 1993
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Rudiger Dieckmann, Stephen L. Sass
  • Patent number: 5074941
    Abstract: Metal-ceramic interfaces of enhanced strength are produced by positioning bodies of ceramic oxides and transition element metals or alloys containing such in abutting relationship, and heating in air at a temperature ranging from 500.degree. C. to just below the melting point of the metal of the metal body to join said bodies and then subsequently heat treating said joined bodies in a reducing atmosphere at a temperature in the range of 300.degree. C. to 1200.degree. C. to form intermetallic compound layer at the interface.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: December 24, 1991
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Stephen L. Sass, Rishi Raj, Fuh-Sheng Shieu