Patents by Inventor Zhifeng Ren

Zhifeng Ren 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: 20150270465
    Abstract: A thermoelectric half-Heusler material comprising niobium (Nb), iron (Fe) and antimony (Sb) wherein the material comprises grains having a mean grain size less than one micron. A method of making a nanocomposite half-Heusler thermoelectric material includes melting constituent elements of the thermoelectric material to form an alloy of the thermoelectric material, comminuting (e.g., ball milling) the alloy of the thermoelectric material into nanometer scale mean size particles, and consolidating the nanometer size particles to form the half-Heusler thermoelectric material comprising at least niobium (Nb), iron (Fe) and antimony (Sb) and having grains with a mean grain size less than one micron.
    Type: Application
    Filed: March 24, 2015
    Publication date: September 24, 2015
    Inventors: Giri Joshi, Jian Yang, Michael Engber, Tej Pantha, Martin Cleary, Zhifeng Ren, Ran He, Boris Kozinsky
  • Patent number: 9110055
    Abstract: A nanocoaxial sensor includes an outer conductor, an inner conductor, a dielectric material disposed between the outer and inner conductors, a nanocavity sized to allow target species to enter the nanocavity between the outer and inner conductors, and an active sensing element immobilized within the nanocavity on at least one of the inner or outer conductors. The active sensing element is adapted to selectively capture the at least one of the target species.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: August 18, 2015
    Assignee: The Trustees of Boston College
    Inventors: Dong Cai, Thomas Chiles, Krzysztof Kempa, Michael Naughton, Zhifeng Ren, Paudel Trilochan
  • Patent number: 9099601
    Abstract: Materials having improved thermoelectric properties are disclosed. In some embodiments, lead telluride/selenide based materials with improved figure of merit and mechanical properties are disclosed. In some embodiments, the lead telluride/selenide based materials of the present disclosure are p-type thermoelectric materials formed by adding sodium (Na), silicon (Si) or both to thallium doped lead telluride materials. In some embodiments, the lead telluride/selenide based materials are formed by doping lead telluride/selenides with potassium.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: August 4, 2015
    Assignees: The Trustees of Boston College, Massachusetts Institute of Technology
    Inventors: Zhifeng Ren, Qinyong Zhang, Qian Zhang, Gang Chen
  • Patent number: 9048004
    Abstract: Thermoelectric materials and methods of making thermoelectric materials having a nanometer mean grain size less than 1 micron. The method includes combining and arc melting constituent elements of the thermoelectric material to form a liquid alloy of the thermoelectric material and casting the liquid alloy of the thermoelectric material to form a solid casting of the thermoelectric material. The method also includes ball milling the solid casting of the thermoelectric material into nanometer mean size particles and sintering the nanometer size particles to form the thermoelectric material having nanometer scale mean grain size.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: June 2, 2015
    Inventors: Zhifeng Ren, Xiao Yan, Giri Joshi, Shuo Chen, Gang Chen, Bed Poudel, James Christopher Caylor
  • Publication number: 20150107660
    Abstract: Super-transparent electrodes for photovoltaic applications are disclosed. In some embodiments, a photovoltaic cell (1) includes an absorber material (16) capable of absorbing solar energy and converting the absorbed energy into electrical current; a window electrode (10) disposed on a light-entry surface of the absorber material (16), the window electrode (10) comprising an anti-reflective coating (ARC) layer (12) and a metallic layer (13), and a rear electrode (18) disposed on a surface of the absorber material (16) in opposing relation to the window electrode (10), wherein the rear electrode (18) in combination with the window electrode (10) are configured to collect electrical current generated in the absorber material (16).
    Type: Application
    Filed: June 27, 2012
    Publication date: April 23, 2015
    Applicant: The Trustees of Boston College
    Inventors: Krzysztof J. Kempa, Zhifeng Ren, Yang Wang
  • Patent number: 9011763
    Abstract: The present invention is generally directed to nanocomposite thermoelectric materials that exhibit enhanced thermoelectric properties. The nanocomposite materials include two or more components, with at least one of the components forming nano-sized structures within the composite material. The components are chosen such that thermal conductivity of the composite is decreased without substantially diminishing the composite's electrical conductivity. Suitable component materials exhibit similar electronic band structures. For example, a band-edge gap between at least one of a conduction band or a valence band of one component material and a corresponding band of the other component material at interfaces between the components can be less than about 5kBT, wherein kB is the Boltzman constant and T is an average temperature of said nanocomposite composition.
    Type: Grant
    Filed: September 20, 2012
    Date of Patent: April 21, 2015
    Assignees: Massachusetts Institute of Technology, Trustees of Boston College
    Inventors: Gang Chen, Mildred Dresselhaus, Zhifeng Ren
  • Publication number: 20150068574
    Abstract: Thermoelectric materials with high figures of merit, ZT values, are disclosed. In many instances, such materials include nano-sized domains (e.g., nanocrystalline), which are hypothesized to help increase the ZT value of the material (e.g., by increasing phonon scattering due to interfaces at grain boundaries or grain/inclusion boundaries). The ZT value of such materials can be greater than about 1, 1.2, 1.4, 1.5, 1.8, 2 and even higher. Such materials can be manufactured from a thermoelectric starting material by generating nanoparticles therefrom, or mechanically alloyed nanoparticles from elements which can be subsequently consolidated (e.g., via direct current induced hot press) into a new bulk material. Non-limiting examples of starting materials include bismuth, lead, and/or silicon-based materials, which can be alloyed, elemental, and/or doped. Various compositions and methods relating to aspects of nanostructured theromoelectric materials (e.g., modulation doping) are further disclosed.
    Type: Application
    Filed: October 17, 2014
    Publication date: March 12, 2015
    Inventors: Zhifeng Ren, Bed Poudel, Gang Chen, Yucheng Lan, Dezhi Wang, Qing Hao, Mildred Dresselhaus, Yi Ma, Xiao Yan, Xiaoyuan Chen, Xiaowei Wang, Joshi R. Giri, Bo Yu
  • Publication number: 20150031582
    Abstract: A method comprising (a) obtaining one or more biological samples from a subject wherein the subject has undergone an organ transplant; (b) determining the amount and type of one or more volatile organic compounds in the biological sample; and (c) correlating the amount of volatile organic compounds to a degree of transplant rejection. A device comprising a plurality of sensors configured to detect a plurality of volatile organic compounds in a biological sample of a subject having undergone an organ transplant.
    Type: Application
    Filed: July 28, 2014
    Publication date: January 29, 2015
    Applicant: UNIVERSITY OF HOUSTON SYSTEM
    Inventors: Dong Cai, Zhifeng Ren, Xian C. Li, Renard L. Thomas
  • Publication number: 20150015960
    Abstract: A solar selective coating includes a substrate, a cermet layer having nanoparticles therein deposited on the substrate, and an anti-reflection layer deposited on the cermet layer. The cermet layer and the anti-reflection layer may each be formed of intermediate layers. A method for constructing a solar-selective coating is disclosed and includes preparing a substrate, depositing a cermet layer on the substrate, and depositing an anti-reflection layer on the cermet layer.
    Type: Application
    Filed: June 6, 2014
    Publication date: January 15, 2015
    Inventors: Zhifeng Ren, Feng Cao, Tianyi Sun, Gang Chen
  • Publication number: 20140377120
    Abstract: A method of manufacturing a thermoelectric material comprising: ball-milling a compound comprising a plurality of components, the first component M comprising at least one of a rare earth metal, an actinide, an alkaline-earth metal, and an alkali metal, the second component T comprising a metal of subgroup VIII, and the third component X comprises a pnictogen atom. The compound may be ball-milled for up to 5 hours, and then thermo-mechanically processed by, for example, hot pressing the compound for less than two hours. Subsequent to the thermo-mechanical processing, the compound comprises a single filled skutterudite phase with a dimensionless figure of merit (ZT) above 1.0 and the compound has a composition following a formula of MT4X12.
    Type: Application
    Filed: June 19, 2014
    Publication date: December 25, 2014
    Inventors: Qing Jie, Zhifeng Ren
  • Publication number: 20140377579
    Abstract: A transparent flexible nanomesh having at least one conductive element and sheet resistance less than 300?/? when stretched to a strain of 200% in at least one direction. The nanomesh is formed by depositing a sacrificial film, depositing, etching, and oxidizing a first metal layer on the film, etching the sacrificial film, depositing a second metal layer, and removing the first metal layer to form a nanomesh on the substrate.
    Type: Application
    Filed: June 6, 2014
    Publication date: December 25, 2014
    Inventors: Zhifeng Ren, Tianyi Sun, Chuanfei Guo
  • Publication number: 20140377901
    Abstract: Disclosed are methods for the manufacture of n-type and p-type filled skutterudite thermoelectric legs of an electrical contact. A first material of CoSi2 and a dopant are ball-milled to form a first powder which is thermo-mechanically processed with a second powder of n-type skutterudite to form a n-type skutterudite layer disposed between a first layer and a third layer of the doped-CoSi2. In addition, a plurality of components such as iron, and nickel, and at least one of cobalt or chromium are ball-milled form a first powder that is thermo-mechanically processed with a p-type skutterudite layer to form a p-type skutterudite layer “second layer” disposed between a first and a third layer of the first powder. The specific contact resistance between the first layer and the skutterudite layer for both the n-type and the p-type skutterudites subsequent to hot-pressing is less than about 10.0 ??·cm2.
    Type: Application
    Filed: June 20, 2014
    Publication date: December 25, 2014
    Inventors: Qing Jie, Zhifeng Ren, Gang Chen
  • Publication number: 20140366924
    Abstract: A thermoelectric composition comprising tin (Sn), tellurium (Te) and at least one dopant that comprises a peak dimensionless figure of merit (ZT) of 1.1 and a Seebeck coefficient of at least 50 ?V/K and a method of manufacturing the thermoelectric composition. A plurality of components are disposed in a ball-milling vessel, wherein the plurality of components comprise tin (Sn), tellurium (Te), and at least one dopant such as indium (In). The components are subsequently mechanically and thermally processed, for example, by hot-pressing. In response to the mechanical-thermally processing, a thermoelectric composition is formed, wherein the thermoelectric composition comprises a dimensionless figure of merit (ZT) of the thermoelectric composition is at least 0.8, and wherein a Seebeck coefficient of the thermoelectric composition is at least 50 ?V/K at any temperature.
    Type: Application
    Filed: June 17, 2014
    Publication date: December 18, 2014
    Inventors: Zhifeng Ren, Qian Zhang
  • Patent number: 8883047
    Abstract: Compositions related to skutterudite-based thermoelectric materials are disclosed. Such compositions can result in materials that have enhanced ZT values relative to one or more bulk materials from which the compositions are derived. Thermoelectric materials such as n-type and p-type skutterudites with high thermoelectric figures-of-merit can include materials with filler atoms and/or materials formed by compacting particles (e.g., nanoparticles) into a material with a plurality of grains each having a portion having a skutterudite-based structure. Methods of forming thermoelectric skutterudites, which can include the use of hot press processes to consolidate particles, are also disclosed. The particles to be consolidated can be derived from (e.g., grinded from), skutterudite-based bulk materials, elemental materials, other non-Skutterudite-based materials, or combinations of such materials.
    Type: Grant
    Filed: April 30, 2009
    Date of Patent: November 11, 2014
    Assignees: Massachusetts Institute of Technology, Trustees of Boston College
    Inventors: Zhifeng Ren, Jian Yang, Xiao Yan, Qinyu He, Gang Chen, Qing Hao
  • Patent number: 8865995
    Abstract: Thermoelectric materials with high figures of merit, ZT values, are disclosed. In many instances, such materials include nano-sized domains (e.g., nanocrystalline), which are hypothesized to help increase the ZT value of the material (e.g., by increasing phonon scattering due to interfaces at grain boundaries or grain/inclusion boundaries). The ZT value of such materials can be greater than about 1, 1.2, 1.4, 1.5, 1.8, 2 and even higher. Such materials can be manufactured from a thermoelectric starting material by generating nanoparticles therefrom, or mechanically alloyed nanoparticles from elements which can be subsequently consolidated (e.g., via direct current induced hot press) into a new bulk material. Non-limiting examples of starting materials include bismuth, lead, and/or silicon-based materials, which can be alloyed, elemental, and/or doped. Various compositions and methods relating to aspects of nanostructured thermoelectric materials (e.g., modulation doping) are further disclosed.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: October 21, 2014
    Assignees: Trustees of Boston College, Massachusetts Institute of Technology
    Inventors: Zhifeng Ren, Bed Poudel, Gang Chen, Yucheng Lan, Dezhi Wang, Qing Hao, Mildred Dresselhaus, Yi Ma, Xiao Yan, Xiaoyuan Chen, Xiaowei Wang, Joshi R. Giri, Bo Yu
  • Publication number: 20140186209
    Abstract: Compositions related to skutterudite-based thermoelectric materials are disclosed. Such compositions can result in materials that have enhanced ZT values relative to one or more bulk materials from which the compositions are derived. Thermoelectric materials such as n-type and p-type skutterudites with high thermoelectric figures-of-merit can include materials with filler atoms and/or materials formed by compacting particles (e.g., nanoparticles) into a material with a plurality of grains each having a portion having a skutterudite-based structure. Methods of forming thermoelectric skutterudites, which can include the use of hot press processes to consolidate particles, are also disclosed. The particles to be consolidated can be derived from (e.g., grinded from), skutterudite-based bulk materials, elemental materials, other non-Skutterudite-based materials, or combinations of such materials.
    Type: Application
    Filed: March 5, 2014
    Publication date: July 3, 2014
    Applicants: TRUSTEES OF BOSTON COLLEGE, MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: Zhifeng Ren, Jian Yang, Xiao Yan, Qinyu He, Gang Chen, Qing Hao
  • Publication number: 20140166103
    Abstract: Broadband metamaterial absorbers are disclosed. In some embodiments, a photovoltaic cell includes a light absorbing layer capable of absorbing solar energy and converting the absorbed energy into electrical current; a perforated conductive film disposed on a light absorbing surface of the light absorbing layer, the conductive film being configured to increase light absorption in the light absorbing layer; and a rear electrode disposed on a surface of the absorbing layer opposite to the light absorbing surface of the light absorbing layer, wherein the rear electrode and the conductive film are in electrical communication with the absorbing layer to collect electrical current generated in the light absorbing material.
    Type: Application
    Filed: December 19, 2013
    Publication date: June 19, 2014
    Applicant: The Trustees of Boston College
    Inventors: Krzysztof J. Kempa, Zhifeng Ren, Yang Wang
  • Publication number: 20140109895
    Abstract: Metallic composite phase-change materials and methods of using are disclosed. In some embodiments, a thermal energy storage module is provide that included one or more phase change alloys having a variable phase transition temperature between about 400° C. and about 1200° C. and having a latent heat of more than about 200 kJ/kg.
    Type: Application
    Filed: October 22, 2013
    Publication date: April 24, 2014
    Applicants: Massachusetts Institute of Technology, The Trustees of Boston College
    Inventors: Zhifeng Ren, Hengzhi Wang, Hui Wang, Gang Chen, Xiaobo Li, Keivan Esfarjani
  • Publication number: 20140102498
    Abstract: Methods of fabricating a thermoelectric element with reduced yield loss include forming a solid body of thermoelectric material having first dimension of 150 mm or more and thickness dimension of 5 mm or less, and dicing the body into a plurality of thermoelectric legs, without cutting along the thickness dimension of the body. Further methods include providing a metal material over a surface of a thermoelectric material, and hot pressing the metal material and the thermoelectric material to form a solid body having a contact metal layer and a thermoelectric material layer.
    Type: Application
    Filed: October 9, 2013
    Publication date: April 17, 2014
    Applicant: GMZ Energy, Inc.
    Inventors: Bed Poudel, Giri Joshi, Jian Yang, Tej Panta, James Christopher Caylor, Jonathan D'Angelo, Zhifeng Ren
  • Patent number: 8698267
    Abstract: An electrode includes a substantially planar metallic thin film layer with a patterned structure including a plurality of parallel lines or a plurality of crossed lines, the metallic thin film layer configured to transmit an incident light through the metallic thin film layer.
    Type: Grant
    Filed: September 8, 2011
    Date of Patent: April 15, 2014
    Assignee: South China Normal University
    Inventors: Yang Wang, Krzysztof Kempa, Zhifeng Ren