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: 7252749Abstract: 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: GrantFiled: November 30, 2001Date of Patent: August 7, 2007Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Bo Gao, Guozhen Yue, Soojin Oh
-
Patent number: 7245692Abstract: 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: GrantFiled: April 25, 2006Date of Patent: July 17, 2007Assignee: The University of North Carolina at Chapel HillInventors: Jianping Lu, Otto Z. Zhou, Jian Zhang
-
Patent number: 7227924Abstract: 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: GrantFiled: February 7, 2005Date of Patent: June 5, 2007Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Yuan Cheng, Jian Zhang, Yueh Lee, Jianping Lu, Weili Lin
-
Patent number: 7220971Abstract: 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: GrantFiled: December 28, 2005Date of Patent: May 22, 2007Assignee: The University of North Carolina at Chapel HillInventors: Sha X. Chang, Otto Z. Zhou
-
Patent number: 7147894Abstract: 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: GrantFiled: March 25, 2002Date of Patent: December 12, 2006Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Hideo Shimoda, Soojin Oh
-
Patent number: 7129513Abstract: 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: GrantFiled: June 2, 2004Date of Patent: October 31, 2006Assignee: Xintek, Inc.Inventors: Otto Z. Zhou, Jianping Lu, Changkun Dong, Bo Gao
-
Patent number: 7082182Abstract: 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: GrantFiled: August 20, 2004Date of Patent: July 25, 2006Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Jianping Lu, Yueh Lee, Weili Lin, Yuan Cheng, Jian Zhang
-
Patent number: 7014743Abstract: 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: GrantFiled: December 9, 2003Date of Patent: March 21, 2006Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Jie Tang, Huaizhi Geng, Lu-Chang Qin, Jian Zhang, Guang Yang
-
Patent number: 6980627Abstract: 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: GrantFiled: July 9, 2003Date of Patent: December 27, 2005Assignee: Xintek, Inc.Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou
-
Patent number: 6969690Abstract: 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: GrantFiled: March 18, 2004Date of Patent: November 29, 2005Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Soojin Oh, Jian Zhang, Yuan Cheng, Hideo Shimoda
-
Patent number: 6965199Abstract: 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: GrantFiled: March 27, 2001Date of Patent: November 15, 2005Assignees: The University of North Carolina at Chapel Hill, Tyco Electronics CorporationInventors: Brian R. Stoner, Otto Z. Zhou, Rachel A. Rosen, William H. Simendinger, III, Chris Debbaut
-
Patent number: 6876724Abstract: 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: GrantFiled: January 22, 2002Date of Patent: April 5, 2005Assignee: The University of North Carolina - Chapel HillInventors: Otto Z. Zhou, Jianping Lu, Qi Qiu
-
Patent number: 6850595Abstract: 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: GrantFiled: December 4, 2002Date of Patent: February 1, 2005Assignee: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Jianping Lu
-
Publication number: 20040256975Abstract: 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: ApplicationFiled: June 19, 2003Publication date: December 23, 2004Applicant: APPLIED NANOTECHNOLOGIES, INC.Inventors: Bo Gao, Otto Z. Zhou
-
Publication number: 20040240616Abstract: 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: ApplicationFiled: May 30, 2003Publication date: December 2, 2004Applicant: APPLIED NANOTECHNOLOGIES, INC.Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou
-
Publication number: 20040241896Abstract: 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: ApplicationFiled: March 18, 2004Publication date: December 2, 2004Applicant: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Soojin Oh, Jian Zhang, Yuan Cheng, Hideo Shimoda
-
Publication number: 20040213378Abstract: 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: ApplicationFiled: April 24, 2003Publication date: October 28, 2004Applicant: The University of North Carolina at Chapel HillInventors: Otto Z. Zhou, Jianping Lu, Yueh Lee, Weili Lin, Yuan Cheng, Jian Zhang
-
Publication number: 20040173378Abstract: 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: ApplicationFiled: December 9, 2003Publication date: September 9, 2004Applicant: UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILLInventors: Otto Z. Zhou, Jie Tang, Huaizhi Geng, Lu-Chang Qin, Jian Zhang, Guang Yang
-
Patent number: 6787122Abstract: 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: GrantFiled: June 18, 2001Date of Patent: September 7, 2004Assignee: The University of North Carolina at Chapel HillInventor: Otto Z. Zhou
-
Publication number: 20040114721Abstract: 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: ApplicationFiled: July 9, 2003Publication date: June 17, 2004Applicant: Applied Nanotechnologies, Inc.Inventors: Qi Qiu, Jianping Lu, Otto Z. Zhou