Patents by Inventor Alexander K. Zettl

Alexander K. Zettl 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: 20120253000
    Abstract: An embodiment of a microcapsule includes a shell surrounding a space, a liquid within the shell, and a light absorbing material within the liquid. An embodiment of a method of making microcapsules includes forming a mixture of a light absorbing material and an organic solution. An emulsion of the mixture and an aqueous solution is then formed. A polymerization agent is added to the emulsion, which causes microcapsules to be formed. Each microcapsule includes a shell surrounding a space, a liquid within the shell, and light absorbing material within the liquid. An embodiment of a method of using microcapsules includes providing phototriggerable microcapsules within a bulk material. Each of the phototriggerable microcapsules includes a shell surrounding a space, a chemically reactive material within the shell, and a light absorbing material within the shell.
    Type: Application
    Filed: September 2, 2010
    Publication date: October 4, 2012
    Applicant: The Regents of the University of California
    Inventors: David C. Okawa, Stefan J. Pastine, Alexander K. Zettl, Jean M.J. Frechet
  • Patent number: 8257932
    Abstract: Disclosed herein are methods and materials by which nanostructures such as carbon nanotubes, nanorods, etc. are bound to lectins and/or polysaccharides and prepared for administration to cells. Also disclosed are complexes comprising glycosylated nanostructures, which bind selectively to cells expressing glycosylated surface molecules recognized by the lectin. Exemplified is a complex comprising a carbon nanotube functionalized with a lipid-like alkane, linked to a polymer bearing repeated ?-N-acetylgalactosamine sugar groups. This complex is shown to selectively adhere to the surface of living cells, without toxicity. In the exemplified embodiment, adherence is mediated by a multivalent lectin, which binds both to the cells and the ?-N-acetylgalactosamine groups on the nanostructure.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: September 4, 2012
    Assignee: The Regents of the University of California
    Inventors: Xing Chen, Carolyn R. Bertozzi, Alexander K. Zettl
  • Publication number: 20120183738
    Abstract: An embodiment of a method of suspending a graphene membrane on a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended on the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a suspended graphene membrane under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.
    Type: Application
    Filed: March 14, 2012
    Publication date: July 19, 2012
    Applicant: The Regents of the University of California
    Inventors: Alexander K. Zettl, Jannik Christian Meyer
  • Publication number: 20120118551
    Abstract: An embodiment of a heat transfer interface includes a solid material having first and second surfaces, and a nanotube forest covering at least a portion of the first surface, In operation in a heat exchanger, the heat transfer interface transmits heat from a first side to a second side of the heat transfer interface. An embodiment of a method of improving heat transfer in a heat exchanger includes applying a nanotube forest to a heat transfer surface of a heat transfer interface and installing the heat transfer interface in the heat exchanger.
    Type: Application
    Filed: March 8, 2010
    Publication date: May 17, 2012
    Applicant: The Regents of the University of California
    Inventor: Alexander K. Zettl
  • Publication number: 20120088934
    Abstract: Disclosed herein is a sequential functionalization methodology for the covalent modification of nanotubes with between one and four repeat units of a polymer. Covalent attachment of oligomer units to the surface of nanotubes results in oligomer units forming an organic sheath around the nanotubes, polymer-functionalized-nanotubes (P-NTs). P-NTs possess chemical functionality identical to that of the functionalizing polymer, and thus provide nanoscale scaffolds which may be readily dispersed within a monomer solution and participate in the polymerization reaction to form a polymer-nanotube/polymer composite. Formation of polymer in the presence of P-NTs leads to a uniform dispersion of nanotubes within the polymer matrix, in contrast to aggregated masses of nanotubes in the case of pristine-NTs.
    Type: Application
    Filed: June 16, 2011
    Publication date: April 12, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Alexander K. Zettl, Toby Sainsbury, Jean M.J. Frechet
  • Patent number: 8120448
    Abstract: A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: February 21, 2012
    Assignee: The Regents of the University of California
    Inventors: Haibing Peng, Alexander K. Zettl
  • Publication number: 20110253205
    Abstract: The present disclosure is directed to an optimized structure for an exciton-based photovoltaic cell, in which the bulk heterojunction between the electron donor (typically an organic polymeric semiconductor) and an electron acceptor (e.g., silicon or titanium or titania) minimizes the necessary exciton travel distance to the heterojunction in three dimensions. The configuration is arrayed in three dimensions, such that one member of the heterojunction pair, such as the electron acceptor is in the form of a number of nanoscale channels, extending to an electrode. The channels extend through a photovoltaic matrix material in a predetermined three-dimensional configuration.
    Type: Application
    Filed: September 25, 2009
    Publication date: October 20, 2011
    Inventors: Jeffrey C. Grossman, Alexander K. Zettl
  • Publication number: 20110253217
    Abstract: Disclosed are methods of using magnetic or electric fields to align magnetically responsive nanoparticles in a polymeric matrix, which has not yet been completely solidified. The nanoparticles are preferably magnetically doped, then blended with photovoltaic polymer material to form devices. The methods provided are particularly useful for the formation of solar cell devices. The devices include nanostructured electron-conducting channels arranged approximately parallel to one another, where the channels comprise magnetically doped materials, as well as photovoltaic materials interspersed with the nanostructured electron-conducting channels. The method provides a way to control the morphology of blended photovoltaic devices, which will improve efficiencies. In addition, the new method provides a way to control the growth of novel, cheap, solar cells, which can in turn lead to enhanced performance.
    Type: Application
    Filed: September 28, 2009
    Publication date: October 20, 2011
    Inventors: Jeffrey C. Grossman, Alexander K. Zettl
  • Publication number: 20110247676
    Abstract: The present invention provides a photovoltaic cell, which is contained within a photonic crystal structure. The photonic crystal is at least two-dimensional, and contains defects to guide incident light, e.g., sunlight, into a crystal cavity, where the concentrated light is guided into a cavity, preferably a photonic optical cavity, which is also a photovoltaic region comprising a semiconductor heterojunction for forming a photovoltaic current.
    Type: Application
    Filed: September 28, 2009
    Publication date: October 13, 2011
    Applicant: The Regents of the University of California
    Inventors: Jeffrey C. Grossman, Alexander K. Zettl
  • Patent number: 8033445
    Abstract: A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: October 11, 2011
    Assignee: The Regents of the University of California
    Inventors: Caglar O. Girit, Alexander K. Zettl
  • Publication number: 20110226330
    Abstract: The present invention provides novel strategies for mitigating the Staebler-Wronski Effect (SWE), that is, the light induced degradation in performance of photoconductivity in amorphous silicon. Materials according to the present invention include alloys or composites of amorphous silicon which affect the elasticity of the materials, amorphous silicon that has been grown on a flexed substrate, compression sandwiched comprising amorphous silicon, and amorphous silicon containing nanoscale features that allow stress to be relieved. The composites are formed with nanoparticles such as nanocrystals and nanotubes. Preferred are boron nitride nanotubes (BNNT) including those that have been surface modified.
    Type: Application
    Filed: August 11, 2009
    Publication date: September 22, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Jeffrey C. Grossman, Alexander K. Zettl, Lucas Wagner
  • Publication number: 20110226840
    Abstract: A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.
    Type: Application
    Filed: November 13, 2008
    Publication date: September 22, 2011
    Applicant: The Regents of the University of California
    Inventors: Caglar O. Girit, Alexander K. Zettl
  • Publication number: 20110102068
    Abstract: An embodiment of a graphene device includes a layered structure, first and second electrodes, and a dopant island. The layered structure includes a conductive layer, an insulating layer, and a graphene layer. The electrodes are coupled to the graphene layer. The dopant island is coupled to an exposed surface of the graphene layer between the electrodes. An embodiment of a method of using a graphene device includes providing the graphene device. A voltage is applied to the conductive layer of the graphene device. Another embodiment of a method of using a graphene device includes providing the graphene device without the dopant island. A dopant island is placed on an exposed surface of the graphene layer between the electrodes. A voltage is applied to the conductive layer of the graphene device. A response of the dopant island to the voltage is observed.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 5, 2011
    Applicant: The Regents of the University of California
    Inventors: Vincent Bouchiat, Caglar Girit, Brian Kessler, Alexander K. Zettl
  • Publication number: 20110073562
    Abstract: The present invention provides a method of fabricating at least one single layer hexagonal boron nitride (h-BN). In an exemplary embodiment, the method includes (1) suspending at least one multilayer boron nitride across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure. The present invention also provides a method of fabricating single layer hexagonal boron nitride. In an exemplary embodiment, the method includes (1) providing multilayer boron nitride suspended across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure.
    Type: Application
    Filed: September 30, 2010
    Publication date: March 31, 2011
    Applicant: The Regents of the University of California
    Inventor: Alexander K. Zettl
  • Publication number: 20110006837
    Abstract: The present invention provides for a graphene device comprising: a first gate structure, a second gate structure that is transparent or semi-transparent, and a bilayer graphene coupled to the first and second gate structures, the bilayer graphene situated at least partially between the first and second gate structures. The present invention also provides for a method of investigating semiconductor properties of bilayer graphene and a method of operating the graphene device by producing a bandgap of at least 50 mV within the bilayer graphene by using the graphene device.
    Type: Application
    Filed: June 2, 2010
    Publication date: January 13, 2011
    Inventors: Feng Wang, Yuanbo Zhang, Tsung-ta Tang, Michael F. Crommie, Alexander K. Zettl, Caglar Girit
  • Patent number: 7863798
    Abstract: A nanoscale nanocrystal which may be used as a reciprocating motor is provided, comprising a substrate having an energy differential across it, e.g. an electrical connection to a voltage source at a proximal end; an atom reservoir on the substrate distal to the electrical connection; a nanoparticle ram on the substrate distal to the atom reservoir; a nanolever contacting the nanoparticle ram and having an electrical connection to a voltage source, whereby a voltage applied between the electrical connections on the substrate and the nanolever causes movement of atoms between the reservoir and the ram. Movement of the ram causes movement of the nanolever relative to the substrate. The substrate and nanolever preferably comprise multiwalled carbon nanotubes (MWNTs) and the atom reservoir and nanoparticle ram are preferably metal (e.g. indium) deposited as small particles on the MWNTs.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: January 4, 2011
    Assignee: The Regents of the University of California
    Inventors: Brian C. Regan, Alexander K. Zettl, Shaul Aloni
  • Publication number: 20100271003
    Abstract: A fully-functional radio receiver fabricated from a single nanotube is being disclosed. Simultaneously, a single nanotube can perform the functions of all major components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A DC voltage source, as supplied by a battery, can power the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, successful music and voice reception has been demonstrated. Also disclosed are a radio transmitter and a mass sensor using a nanotube resonator device.
    Type: Application
    Filed: September 3, 2008
    Publication date: October 28, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Kenneth J. Jensen, Alexander K. Zettl, Jeffrey A. Weldon
  • Publication number: 20100214034
    Abstract: A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.
    Type: Application
    Filed: October 19, 2007
    Publication date: August 26, 2010
    Inventors: Hai-bing Peng, Alexander K. Zettl
  • Publication number: 20100204951
    Abstract: A platform that can measure the thermal profiles of devices with nanoscale resolution has been developed. The system measures the local temperature by using an array of nanoscale thermometers. This process can be observed in real time using a high resolution imagining technique such as electron microscopy. The platform can operate at extremely high temperatures.
    Type: Application
    Filed: February 14, 2008
    Publication date: August 12, 2010
    Inventors: Alexander K. Zettl, Gavi E. Begtrup
  • Publication number: 20100167004
    Abstract: Thermal rectifiers using linear nanostructures as core thermal conductors have been fabricated. A high mass density material is added preferentially to one end of the nanostructures to produce an axially non-uniform mass distribution. The resulting nanoscale system conducts heat asymmetrically with greatest heat flow in the direction of decreasing mass density. Thermal rectification has been demonstrated for linear nanostructures that are electrical insulators, such as boron nitride nanotubes, and for nanostructures that are conductive, such as carbon nanotubes.
    Type: Application
    Filed: October 2, 2007
    Publication date: July 1, 2010
    Inventors: Chih-Wei Chang, Arunava Majumdar, Alexander K. Zettl