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).
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Publication number: 20120253000Abstract: 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: ApplicationFiled: September 2, 2010Publication date: October 4, 2012Applicant: The Regents of the University of CaliforniaInventors: David C. Okawa, Stefan J. Pastine, Alexander K. Zettl, Jean M.J. Frechet
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Patent number: 8257932Abstract: 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: GrantFiled: February 20, 2008Date of Patent: September 4, 2012Assignee: The Regents of the University of CaliforniaInventors: Xing Chen, Carolyn R. Bertozzi, Alexander K. Zettl
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Publication number: 20120183738Abstract: 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: ApplicationFiled: March 14, 2012Publication date: July 19, 2012Applicant: The Regents of the University of CaliforniaInventors: Alexander K. Zettl, Jannik Christian Meyer
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Publication number: 20120118551Abstract: 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: ApplicationFiled: March 8, 2010Publication date: May 17, 2012Applicant: The Regents of the University of CaliforniaInventor: Alexander K. Zettl
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Publication number: 20120088934Abstract: 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: ApplicationFiled: June 16, 2011Publication date: April 12, 2012Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Alexander K. Zettl, Toby Sainsbury, Jean M.J. Frechet
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Patent number: 8120448Abstract: 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: GrantFiled: October 19, 2007Date of Patent: February 21, 2012Assignee: The Regents of the University of CaliforniaInventors: Haibing Peng, Alexander K. Zettl
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Publication number: 20110253205Abstract: 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: ApplicationFiled: September 25, 2009Publication date: October 20, 2011Inventors: Jeffrey C. Grossman, Alexander K. Zettl
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Publication number: 20110253217Abstract: 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: ApplicationFiled: September 28, 2009Publication date: October 20, 2011Inventors: Jeffrey C. Grossman, Alexander K. Zettl
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Publication number: 20110247676Abstract: 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: ApplicationFiled: September 28, 2009Publication date: October 13, 2011Applicant: The Regents of the University of CaliforniaInventors: Jeffrey C. Grossman, Alexander K. Zettl
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Patent number: 8033445Abstract: 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: GrantFiled: November 13, 2008Date of Patent: October 11, 2011Assignee: The Regents of the University of CaliforniaInventors: Caglar O. Girit, Alexander K. Zettl
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Publication number: 20110226330Abstract: 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: ApplicationFiled: August 11, 2009Publication date: September 22, 2011Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Jeffrey C. Grossman, Alexander K. Zettl, Lucas Wagner
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Publication number: 20110226840Abstract: 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: ApplicationFiled: November 13, 2008Publication date: September 22, 2011Applicant: The Regents of the University of CaliforniaInventors: Caglar O. Girit, Alexander K. Zettl
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Publication number: 20110102068Abstract: 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: ApplicationFiled: October 29, 2010Publication date: May 5, 2011Applicant: The Regents of the University of CaliforniaInventors: Vincent Bouchiat, Caglar Girit, Brian Kessler, Alexander K. Zettl
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Publication number: 20110073562Abstract: 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: ApplicationFiled: September 30, 2010Publication date: March 31, 2011Applicant: The Regents of the University of CaliforniaInventor: Alexander K. Zettl
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Publication number: 20110006837Abstract: 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: ApplicationFiled: June 2, 2010Publication date: January 13, 2011Inventors: Feng Wang, Yuanbo Zhang, Tsung-ta Tang, Michael F. Crommie, Alexander K. Zettl, Caglar Girit
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Patent number: 7863798Abstract: 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: GrantFiled: September 19, 2005Date of Patent: January 4, 2011Assignee: The Regents of the University of CaliforniaInventors: Brian C. Regan, Alexander K. Zettl, Shaul Aloni
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Publication number: 20100271003Abstract: 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: ApplicationFiled: September 3, 2008Publication date: October 28, 2010Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Kenneth J. Jensen, Alexander K. Zettl, Jeffrey A. Weldon
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Publication number: 20100214034Abstract: 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: ApplicationFiled: October 19, 2007Publication date: August 26, 2010Inventors: Hai-bing Peng, Alexander K. Zettl
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Publication number: 20100204951Abstract: 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: ApplicationFiled: February 14, 2008Publication date: August 12, 2010Inventors: Alexander K. Zettl, Gavi E. Begtrup
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Publication number: 20100167004Abstract: 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: ApplicationFiled: October 2, 2007Publication date: July 1, 2010Inventors: Chih-Wei Chang, Arunava Majumdar, Alexander K. Zettl