Patents by Inventor Timothy David Sands

Timothy David Sands 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).

  • Patent number: 8986835
    Abstract: A GaN nanorod and formation method. Formation includes providing a substrate having a GaN film, depositing SiNx on the GaN film, etching a growth opening through the SiNx and into the GaN film, growing a GaN nanorod through the growth opening, the nanorod having a nanopore running substantially through its centerline. Focused ion beam etching can be used. The growing can be done using organometallic vapor phase epitaxy. The nanopore diameter can be controlled using the growth opening diameter or the growing step duration. The GaN nanorods can be removed from the substrate. The SiNx layer can be removed after the growing step. A SiOx template can be formed on the GaN film and the GaN can be grown to cover the SiOx template before depositing SiNx on the GaN film. The SiOx template can be removed after growing the nanorods.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: March 24, 2015
    Assignee: Purdue Research Foundation
    Inventors: Isaac Harshman Wildeson, Timothy David Sands
  • Patent number: 8754321
    Abstract: A thermoelectric segment and a method for fabricating. The fabricating includes forming structures by depositing thin-film metal-semiconductor multilayers on substrates and depositing metal layers on the multilayers, joining metal bonding layers to form dual structures with combined bonding layers; and removing at least one of the substrates; and using the dual structure to form a thermoelectric segments. The method can include dicing the dual structures before or after removing the substrates. The method can include depositing additional bonding layers and joining dual structures to make thermoelectric segments of different thicknesses. Each multilayer can be about 5-10 ?m thick. Each bonding layer can be about 1-2 ?m thick. The bonding layers can be made of a material having high thermal and electrical conductivity. The multilayers can be (Hf,Zr,Ti,W)N/(Sc,Y,La,Ga,In,Al)N superlattice layers. Metal nitride layers can be deposited between each of the bonding layers and multilayers.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: June 17, 2014
    Assignee: Purdue Research Foundation
    Inventors: Jeremy Leroy Schroeder, Timothy David Sands
  • Publication number: 20120096871
    Abstract: A dynamic switching thermoelectric thermal management system and method is disclosed. The thermal management system includes a heat dissipation device, a thermoelectric module, an ambient temperature sensor, a heat source temperature sensor, an energy storage device and a controller. One side of the thermoelectric module is thermally coupled to the heat source and another side is thermally coupled to the heat dissipation device. The controller periodically samples the temperature sensors and dynamically switches the thermoelectric module between a power generation mode in which the thermoelectric module uses the temperature difference between the heat source and ambient to charge the energy storage device, a cooling mode in which the thermoelectric module is powered to create a voltage difference across the thermoelectric module to cool the heat source, and an idle mode. The thermal management system can be integrated into a portable electronic device, for example a portable computing device.
    Type: Application
    Filed: October 24, 2011
    Publication date: April 26, 2012
    Inventors: Yuefeng Wang, Timothy David Sands
  • Publication number: 20110244235
    Abstract: A GaN nanorod and formation method. Formation includes providing a substrate having a GaN film, depositing SiNx on the GaN film, etching a growth opening through the SiNx and into the GaN film, growing a GaN nanorod through the growth opening, the nanorod having a nanopore running substantially through its centerline. Focused ion beam etching can be used. The growing can be done using organometallic vapor phase epitaxy. The nanopore diameter can be controlled using the growth opening diameter or the growing step duration. The GaN nanorods can be removed from the substrate. The SiNx layer can be removed after the growing step. A SiOx template can be formed on the GaN film and the GaN can be grown to cover the SiOx template before depositing SiNx on the GaN film. The SiOx template can be removed after growing the nanorods.
    Type: Application
    Filed: April 5, 2011
    Publication date: October 6, 2011
    Inventors: Isaac Harshman Wildeson, Timothy David Sands
  • Publication number: 20110126874
    Abstract: A thermoelectric segment and a method for fabricating. The fabricating includes forming structures by depositing thin-film metal-semiconductor multilayers on substrates and depositing metal layers on the multilayers, joining metal bonding layers to form dual structures with combined bonding layers; and removing at least one of the substrates; and using the dual structure to form a thermoelectric segments. The method can include dicing the dual structures before or after removing the substrates. The method can include depositing additional bonding layers and joining dual structures to make thermoelectric segments of different thicknesses. Each multilayer can be about 5-10 ?m thick. Each bonding layer can be about 1-2 ?m thick. The bonding layers can be made of a material having high thermal and electrical conductivity. The multilayers can be (Hf,Zr,Ti,W)N/(Sc,Y,La,Ga,In,Al)N superlattice layers. Metal nitride layers can be deposited between each of the bonding layers and multilayers.
    Type: Application
    Filed: November 30, 2010
    Publication date: June 2, 2011
    Inventors: Jeremy Leroy Schroeder, Timothy David Sands
  • Publication number: 20110079766
    Abstract: A nanopyramid LED and method for forming. The nanopyramid LED includes a silicon substrate, a III-nitride layer deposited thereon, a metal layer deposited thereon; and a nanopyramid LED grown in ohmic contact with the metal layer. The nanopyramid LED can be seeded on the III-nitride layer or metal layer. The metal layer can be a reflecting surface for the nanopyramid LED. The method for forming nanopyramid LEDs includes obtaining a silicon substrate, depositing a III-nitride layer thereon, depositing a metal layer thereon, depositing a dielectric growth layer thereon, etching a dielectric growth template in the growth layer, and growing III-nitride nanopyramid LEDs through the dielectric growth template in ohmic contact with the metal layer. The etching can be performed by focused ion beam etching. The etching can stop in the metal layer or III-nitride layer, so that the nanopyramid LEDs can seed off the metal layer or III-nitride layer, respectively.
    Type: Application
    Filed: October 1, 2010
    Publication date: April 7, 2011
    Inventors: Isaac Harshman Wildeson, Timothy David Sands
  • Publication number: 20090283747
    Abstract: A light emitting diode having a metallized silicon substrate including a silicon base, a buffer layer disposed on the silicon base, a metal layer disposed on the buffer layer, and light emitting layers disposed on the metal layer. The buffer layer can be AlN, and the metal layer ZrN. The light emitting layers can include GaN and InGaN. The metallized silicon substrate can also include an oxidation prevention layer disposed on the metal layer. The oxidation prevention layer can be AlN. The light emitting diode can be formed using an organometallic vapor phase epitaxy process. The intermediate ZrN/AlN layers enable epitaxial growth of GaN on silicon substrates using conventional organometallic vapor phase epitaxy. The ZrN layer provides an integral back reflector, ohmic contact to n-GaN. The AlN layer provides a reaction barrier, thermally conductive interface layer, and electrical isolation layer.
    Type: Application
    Filed: April 15, 2009
    Publication date: November 19, 2009
    Inventors: Mark Oliver Harwood, Vijay Prakash Singh Rawat, Timothy David Sands, Jeremy Leroy Schroeder
  • Patent number: 6335263
    Abstract: A method of forming a low temperature metal bond includes the step of providing a donor substrate, such as a crystallographically oriented donor substrate, including a sapphire donor substrate or a MgO donors substrate. The donor substrate may also be quartz or fused silica. A thin film is grown on a surface of the donor substrate. The thin film may be an oxide, nitride or Perovskite. The invention may be implemented using nitride thin films, including AlN, GaN, InN, and all of their solid solutions, alloys, and multi-layers. An acceptor substrate is then produced. The acceptor substrate may be Si, GaAs, polymers, such as polyimide, or stainless steel for use in microrobotics. A multi-layer metal bond interface for positioning between the thin film and the acceptor substrate is then selected.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: January 1, 2002
    Assignee: The Regents of the University of California
    Inventors: Nathan W. Cheung, Timothy David Sands, William S. Wong