Patents by Inventor Otto Z. Zhou

Otto Z. Zhou 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: 7252749
    Abstract: A method for depositing a coating of a nanostructure material onto a substrate includes: (1) forming a solution or suspension of containing the nanostructure material; (2) selectively adding “chargers” to the solution; (3) immersing electrodes in the solution, the substrate upon which the nanostructure material is to be deposited acting as one of the electrodes; (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode; and (5) subsequent optional processing of the coated substrate.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: August 7, 2007
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Bo Gao, Guozhen Yue, Soojin Oh
  • Patent number: 7245692
    Abstract: X-ray imaging systems and methods are provided that use temporal digital signal processing for reducing noise and for obtaining multiple images simultaneously. An x-ray imaging system can include an x-ray source adapted to generate a pulsed x-ray beam having a predetermined frequency and apply the pulsed x-ray beam to an object to be imaged. An x-ray detector can be adapted to detect x-ray radiation from the object and generate temporal data based on the x-ray radiation. A temporal data analyzer can be adapted to apply a temporal signal process to the temporal data to remove at least a portion of the temporal data having a different frequency than the predetermined frequency.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: July 17, 2007
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Jianping Lu, Otto Z. Zhou, Jian Zhang
  • Patent number: 7227924
    Abstract: Computed tomography scanning systems and methods using a field emission x-ray source are disclosed. An exemplary micro-computed tomography scanner comprises a micro-focus field emission x-ray source, an x-ray detector, an object stage placed between the x-ray source and the detector, an electronic control system and a computer that control the x-ray radiation and detector data collection, and computer software that reconstructs the three dimension image of the object using a series of projection images collected from different projection angles. Exemplary methods obtain a computed tomography image of an object in oscillatory motion using the micro computed tomography scanner.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: June 5, 2007
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Yuan Cheng, Jian Zhang, Yueh Lee, Jianping Lu, Weili Lin
  • Patent number: 7220971
    Abstract: Multi-pixel electron microbeam irradiator systems and methods are provided with particular applicability for selectively irradiating predetermined cells or cell locations. A multi-pixel electron microbeam irradiator system can include a plurality of individually addressable electron field emitters sealed in a vacuum. The multi-pixel electron microbeam irradiator system can include an anode comprising one or more electron permeable portions corresponding to the plurality of electron field emitters. Further, the multi-pixel electron microbeam irradiator system can include a controller operable to individually control electron extraction from each of the electron field emitters for selectively irradiating predetermined locations such as cells or cell locations.
    Type: Grant
    Filed: December 28, 2005
    Date of Patent: May 22, 2007
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Sha X. Chang, Otto Z. Zhou
  • Patent number: 7147894
    Abstract: A method for the self assembly of a macroscopic structure with a pre-formed nano object is provided. The method includes processing a nano object to a desired aspect ratio and chemical functionality and mixing the processed nano object with a solvent to form a suspension. Upon formation of the suspension, a substrate is inserted into the suspension. By either evaporation of the solvent, changing the pH value of the suspension, or changing the temperature of the suspension, the nano objects within the suspension deposit onto the substrate in an orientational order. In addition, a seed crystal may be used in place of the substrate thereby forming single-crystals and free-standing membranes of the nano-objects.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: December 12, 2006
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Hideo Shimoda, Soojin Oh
  • Patent number: 7129513
    Abstract: A field emission ion source has nanostructure materials on at least an emitting edge of the anode electrode. Metal is transferred from a metal reservoir to the emitting edge of the anode, where the metal is transferred to an emitting end of the nanostructure materials and is ionized under an applied electric field. Plural ion sources can be combined to form a field emission ion source device. The numbers of emitting sources are selectable through electric or mechanical switches and different ion extraction potentials can be applied. Various nanostructure materials include: single wall carbon nanotubes and bundles, few-walled carbon nanotubes and bundles, multi-walled carbon nanotubes and bundles, and carbon fiber. Nanostructure-containing material is integrated into the anode by electrophoresis, dielectrophoresis, CVD, screen printing, and mechanical methods.
    Type: Grant
    Filed: June 2, 2004
    Date of Patent: October 31, 2006
    Assignee: Xintek, Inc.
    Inventors: Otto Z. Zhou, Jianping Lu, Changkun Dong, Bo Gao
  • Patent number: 7082182
    Abstract: Computed tomography device comprising an x-ray source and an x-ray detecting unit. The x-ray source comprises a cathode with a plurality of individually programmable electron emitting units that each emit an electron upon an application of an electric field, an anode target that emits an x-ray upon impact by the emitted electron, and a collimator. Each electron emitting unit includes an electron field emitting material. The electron field emitting material includes a nanostructured material or a plurality of nanotubes or a plurality of nanowires. Computed tomography methods are also provided.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: July 25, 2006
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Jianping Lu, Yueh Lee, Weili Lin, Yuan Cheng, Jian Zhang
  • Patent number: 7014743
    Abstract: A method for depositing a nanostructure-containing material onto an object or substrate includes one or more of the following: (1) forming a solution or suspension of nanostructure-containing material, (2) selectively adding “chargers” to the solution, (3) immersing electrodes in the solution, the substrate or object upon which the nanostructure material is to be deposited acting as one of the electrodes, (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode, and (5) subsequent optional processing of the coated substrate. Associated objects and devices are also provided. A method for separating nanostructures based on their properties and/or geometry is also described.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: March 21, 2006
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Jie Tang, Huaizhi Geng, Lu-Chang Qin, Jian Zhang, Guang Yang
  • Patent number: 6980627
    Abstract: An x-ray generating device includes at least one field-emission cold cathode having a substrate and incorporating nanostructure-containing material including carbon nanotubes. The device further includes at least one anode target. Associated methods are also described.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: December 27, 2005
    Assignee: Xintek, Inc.
    Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou
  • Patent number: 6969690
    Abstract: Methods and apparatus are described for patterned deposition of nanostructure-containing materials by self-assembly and related articles. According to an exemplary embodiment self-assembly method for depositing nanostructure-containing materials includes forming a nanostructure-containing material. The nanostructure-containing material is chemically functionalized and dispersed in a liquid medium to form a suspension. At least a portion of a substrate having a surface that can attract the functionalized nanostructure-containing material is brought into contact with the suspension. The substrate is separated from the suspension. The nanostructure-containing material adheres to the portion of the substrate when separated from the suspension. According to another exemplary embodiment, hydrophilic and hydrophobic regions are formed on the surface of the substrate before bringing the substrate into contact with the suspension.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: November 29, 2005
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Soojin Oh, Jian Zhang, Yuan Cheng, Hideo Shimoda
  • Patent number: 6965199
    Abstract: An improved electrode capable of smaller variances and mean breakdown voltage, increased breakdown reliability, smaller electron emission turn-on requirements, and stable electron emissions capable of high current densities include a first electrode material, an adhesion-promoting layer disposed on at least one surface of the first electrode material, and a nanostructure-containing material disposed on at least a portion of the adhesion promoting layer. An improved gas discharge device is provided incorporating an electrode formed as described above. An improved circuit incorporating an improved gas discharge tube device as set forth above is also provided. Further, an improved telecommunications network, incorporating an improved gas discharge tube device as set forth above can also be provided. An improved lighting device is also provided incorporating an electrode constructed as described above.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: November 15, 2005
    Assignees: The University of North Carolina at Chapel Hill, Tyco Electronics Corporation
    Inventors: Brian R. Stoner, Otto Z. Zhou, Rachel A. Rosen, William H. Simendinger, III, Chris Debbaut
  • Patent number: 6876724
    Abstract: A structure to generate x-rays has a plurality of stationary and individually electrically addressable field emissive electron sources with a substrate composed of a field emissive material, such as carbon nanotubes. Electrically switching the field emissive electron sources at a predetermined frequency field emits electrons in a programmable sequence toward an incidence point on a target. The generated x-rays correspond in frequency and in position to that of the field emissive electron source. The large-area target and array or matrix of emitters can image objects from different positions and/or angles without moving the object or the structure and can produce a three dimensional image. The x-ray system is suitable for a variety of applications including industrial inspection/quality control, analytical instrumentation, security systems such as airport security inspection systems, and medical imaging, such as computed tomography.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: April 5, 2005
    Assignee: The University of North Carolina - Chapel Hill
    Inventors: Otto Z. Zhou, Jianping Lu, Qi Qiu
  • Patent number: 6850595
    Abstract: An x-ray generating device includes a field emission cathode formed at least partially from a nanostructure-containing material having an emitted electron current density of at least 4 A/cm2. High energy conversion efficiency and compact design are achieved due to easy focusing of cold cathode emitted electrons and dramatic reduction of heating at the anode. In addition, by pulsing the field between the cathode and the gate or anode and focusing the electron beams at different anode materials, pulsed x-ray radiation with varying energy can be generated from a single device.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: February 1, 2005
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Jianping Lu
  • Publication number: 20040256975
    Abstract: This invention discloses electron field-emission cathodes with enhanced performance for vacuum and gaseous electronics and methods of fabricating these cathodes. The cathodes of the present invention comprise nanomaterials, such as carbon nanotubes, and metals or metal-containing compounds or alloys. In gas discharge devices, the present field-emission materials or cathodes work at room temperature and have much lower breakdown voltage or cathode fall (e.g.—the voltage drop between the plasma discharge region and the cathode) than conventional cathodes. The invention enables the developing of gas discharge devices with greatly enhanced energy efficiency and operating lifetime.
    Type: Application
    Filed: June 19, 2003
    Publication date: December 23, 2004
    Applicant: APPLIED NANOTECHNOLOGIES, INC.
    Inventors: Bo Gao, Otto Z. Zhou
  • Publication number: 20040240616
    Abstract: A multi-beam x-ray generating device includes a stationary field-emission cathode having a plurality of stationary and individually controllable electron-emitting pixels disposed in a predetermined pattern on the cathode, an anode opposing the cathode comprising a plurality of focal spots disposed in a predetermined pattern that corresponds to the predetermined pattern of the pixels, and a vacuum chamber enveloping the anode and cathode.
    Type: Application
    Filed: May 30, 2003
    Publication date: December 2, 2004
    Applicant: APPLIED NANOTECHNOLOGIES, INC.
    Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou
  • Publication number: 20040241896
    Abstract: Methods and apparatus are described for patterned deposition of nanostructure-containing materials by self-assembly and related articles. According to an exemplary embodiment self-assembly method for depositing nanostructure-containing materials includes forming a nanostructure-containing material. The nanostructure-containing material is chemically functionalized and dispersed in a liquid medium to form a suspension. At least a portion of a substrate having a surface that can attract the functionalized nanostructure-containing material is brought into contact with the suspension. The substrate is separated from the suspension. The nanostructure-containing material adheres to the portion of the substrate when separated from the suspension. According to another exemplary embodiment, hydrophilic and hydrophobic regions are formed on the surface of the substrate before bringing the substrate into contact with the suspension.
    Type: Application
    Filed: March 18, 2004
    Publication date: December 2, 2004
    Applicant: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Soojin Oh, Jian Zhang, Yuan Cheng, Hideo Shimoda
  • Publication number: 20040213378
    Abstract: Computed tomography device comprising an x-ray source and an x-ray detecting unit. The x-ray source comprises a cathode with a plurality of individually programmable electron emitting units that each emit an electron upon an application of an electric field, an anode target that emits an x-ray upon impact by the emitted electron, and a collimator. Each electron emitting unit includes an electron field emitting material. The electron field emitting material includes a nanostructured material or a plurality of nanotubes or a plurality of nanowires. Computed tomography methods are also provided.
    Type: Application
    Filed: April 24, 2003
    Publication date: October 28, 2004
    Applicant: The University of North Carolina at Chapel Hill
    Inventors: Otto Z. Zhou, Jianping Lu, Yueh Lee, Weili Lin, Yuan Cheng, Jian Zhang
  • Publication number: 20040173378
    Abstract: A method for depositing a nanostructure-containing material onto an object or substrate includes one or more of the following: (1) forming a solution or suspension of nanostructure-containing material, (2) selectively adding “chargers” to the solution, (3) immersing electrodes in the solution, the substrate or object upon which the nanostructure material is to be deposited acting as one of the electrodes, (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode, and (5) subsequent optional processing of the coated substrate. Associated objects and devices are also provided. A method for separating nanostructures based on their properties and/or geometry is also described.
    Type: Application
    Filed: December 9, 2003
    Publication date: September 9, 2004
    Applicant: UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL
    Inventors: Otto Z. Zhou, Jie Tang, Huaizhi Geng, Lu-Chang Qin, Jian Zhang, Guang Yang
  • Patent number: 6787122
    Abstract: A method of reducing electronic work function, reducing threshold field emission values, converting semiconducting behavior to metallic behavior, increasing the electron density state at the Fermi level, and increasing electron emission site density, of nanostructure or nanotube-containing material, the method including: forming openings in the nanotube-containing material; introducing a foreign species such as an alkali metal into at least some of the openings; and closing the openings, thereby forming capsules filled with the foreign species, and forming field emission cathode and flat panel displays using these capsules.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: September 7, 2004
    Assignee: The University of North Carolina at Chapel Hill
    Inventor: Otto Z. Zhou
  • Publication number: 20040114721
    Abstract: An x-ray generating device includes at least one field-emission cathode having a substrate and incorporating nanostructure-containing material including carbon nanotubes. The device further includes at least one anode target. Associated methods are also described.
    Type: Application
    Filed: July 9, 2003
    Publication date: June 17, 2004
    Applicant: Applied Nanotechnologies, Inc.
    Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou