Patents by Inventor Shivkumar Chiruvolu

Shivkumar Chiruvolu 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: 7892872
    Abstract: Highly uniform silica nanoparticles can be formed into stable dispersions with a desirable small secondary particle size. The silican particles can be surface modified to form the dispersions. The silica nanoparticles can be doped to change the particle properties and/or to provide dopant for subsequent transfer to other materials. The dispersions can be printed as an ink for appropriate applications. The dispersions can be used to selectively dope semiconductor materials such as for the formation of photovoltaic cells or for the formation of printed electronic circuits.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: February 22, 2011
    Assignee: NanoGram Corporation
    Inventors: Henry Hieslmair, Shivkumar Chiruvolu, Hui Du
  • Publication number: 20100324191
    Abstract: Successful dispersion approaches are described for the formation of dispersion of dry powders of inorganic particles. In some embodiments, it is desirable to form the dispersion in two processing steps in which the particles are surface modified in the second processing step. Composites can be formed using the well dispersed particles to form improved inorganic particle-polymer composites. These composites are suitable for optical applications and for forming transparent films, which can have a relatively high index or refraction. In some embodiments, water can be used to alter the surface chemistry of metal oxide particles.
    Type: Application
    Filed: May 24, 2010
    Publication date: December 23, 2010
    Inventors: Shivkumar Chiruvolu, Hui Du, Nobuyuki Kambe
  • Publication number: 20100314588
    Abstract: Inorganic particle/polymer composites are described that involve chemical bonding between the elements of the composite. In some embodiments, the composite composition includes a polymer having side groups chemically bonded to inorganic particles. Furthermore, the composite composition can include chemically bonded inorganic particles and ordered copolymers. Various electrical, optical and electro-optical devices can be formed from the composites.
    Type: Application
    Filed: August 24, 2010
    Publication date: December 16, 2010
    Inventors: Nobuyuki Kambe, Yigal Dov Blum, Benjamin Chaloner-Gill, Shivkumar Chiruvolu, Sujeet Kumar, David Brent MacQueen
  • Patent number: 7781060
    Abstract: Hollow silica nanoparticles can have well defined non-porous shells with low shell fragmentation and good dispersability. These well defined hollow particles can be formed through the controlled oxidation of silicon nanoparticles in an organic solvent. The hollow nanoparticles can have a submicron secondary particle sizes. The hollow silica nanoparticles can be incorporated into polymer composites, such as low index-of-refraction composites, for appropriate applications.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: August 24, 2010
    Assignee: NanoGram Corporation
    Inventors: Weidong Li, Shivkumar Chiruvolu, Hui Du, Igor Altman, Ronald J. Mosso, Nobuyuki Kambe
  • Publication number: 20100209328
    Abstract: Methods are described that have the capability of producing submicron/nanoscale particles, in some embodiments dispersible, at high production rates. In some embodiments, the methods result in the production of particles with an average diameter less than about 75 nanometers that are produced at a rate of at least about 35 grams per hour. In other embodiments, the particles are highly uniform. These methods can be used to form particle collections and/or powder coatings. Powder coatings and corresponding methods are described based on the deposition of highly uniform submicron/nanoscale particles.
    Type: Application
    Filed: January 13, 2010
    Publication date: August 19, 2010
    Inventors: Xiangxin Bi, Nobuyuki Kambe, Craig R. Horne, James T. Gardner, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, William E. McGovern, Pierre J. DeMascarel, Robert B. Lynch
  • Patent number: 7776406
    Abstract: Nanoscale particles, particle coatings/particle arrays and corresponding consolidated materials are described based on an ability to vary the composition involving a wide range of metal and/or metalloid elements and corresponding compositions. In particular, metalloid oxides and metal-metalloid compositions are described in the form of improved nanoscale particles and coatings formed from the nanoscale particles. Compositions comprising rare earth metals and dopants/additives with rare earth metals are described. Complex compositions with a range of host compositions and dopants/additives can be formed using the approaches described herein. The particle coating can take the form of particle arrays that range from collections of disbursable primary particles to fused networks of primary particles forming channels that reflect the nanoscale of the primary particles. Suitable materials for optical applications are described along with some optical devices of interest.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: August 17, 2010
    Assignee: NeoPhotonics Corporation
    Inventors: Craig R. Horne, Pierre J. DeMascarel, Christian C. Honeker, Benjamin Chaloner-Gill, Herman A. Lopez, Xiangxin Bi, Ronald J. Mosso, William E. McGovern, James T. Gardner, Sujeet Kumar, James A. Gilliam, Vince Pham, Eric Euvrard, Shivkumar Chiruvolu, Jesse Jur
  • Publication number: 20100190288
    Abstract: Thin semiconductor foils can be formed using light reactive deposition. These foils can have an average thickness of less than 100 microns. In some embodiments, the semiconductor foils can have a large surface area, such as greater than about 900 square centimeters. The foil can be free standing or releasably held on one surface. The semiconductor foil can comprise elemental silicon, elemental germanium, silicon carbide, doped forms thereof, alloys thereof or mixtures thereof. The foils can be formed using a release layer that can release the foil after its deposition. The foils can be patterned, cut and processed in other ways for the formation of devices. Suitable devices that can be formed form the foils include, for example, photovoltaic modules and display control circuits.
    Type: Application
    Filed: March 31, 2010
    Publication date: July 29, 2010
    Inventors: Henry Hieslmair, Ronald J. Mosso, Robert B. Lynch, Shivkumar Chiruvolu, William E. McGovern, Craig R. Horne, Narayan Solayappan, Ronald M. Cornell
  • Publication number: 20100174024
    Abstract: Desirable composites of polysiloxane polymers and inorganic nanoparticles can be formed based on the appropriate selection of the surface properties of the particles and the chemical properties of the polymer. High loadings of particles can be achieved with good dispersion through the polymer. The composites can have good optical properties. In some embodiments, the inorganic particles are substantially free of surface modification.
    Type: Application
    Filed: December 31, 2009
    Publication date: July 8, 2010
    Inventors: Hui Du, Shivkumar Chiruvolu, Ang-Ling Chu
  • Publication number: 20100102700
    Abstract: Flame spray pyrolysis can be performed using aqueous solvents for the delivery of metal and/or metalloid oxide precursors while obtaining desirably high flame temperatures for the synthesis of uniform submicron inorganic oxide particles. A multiple liquid channel nozzle can be used to deliver liquid for the formation of the aerosol that is combusted in the flame. One or both channels can deliver liquid with metal/metalloid precursors and/or organic fuels. Flame spray pyrolysis can be used to form metal tungsten oxide submicron particles. Metal tungsten oxide compositions can be used in the formation of transparent electrodes. If the transparent electrodes are formed from polymer inorganic particle composites, the composites can further comprise electrically conductive nanoparticles to improve the electrical conductivity.
    Type: Application
    Filed: October 24, 2008
    Publication date: April 29, 2010
    Inventors: Abhishek Jaiswal, Frank O. Ernst, Shivkumar Chiruvolu, Jia X. Lee, Robert Buchel, Sotiris E. Pratsinis
  • Publication number: 20090288601
    Abstract: Light reactive deposition uses an intense light beam to form particles that are directly coated onto a substrate surface. In some embodiments, a coating apparatus comprising a noncircular reactant inlet, optical elements forming a light path, a first substrate, and a motor connected to the apparatus. The reactant inlet defines a reactant stream path. The light path intersects the reactant stream path at a reaction zone with a product stream path continuing from the reaction zone. The substrate intersects the product stream path. Also, operation of the motor moves the first substrate relative to the product stream. Various broad methods are described for using light driven chemical reactions to produce efficiently highly uniform coatings.
    Type: Application
    Filed: July 30, 2009
    Publication date: November 26, 2009
    Inventors: Xiangxin Bi, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, James T. Gardner, Seung M. Lim, William E. McGovern
  • Patent number: 7575784
    Abstract: Light reactive deposition uses an intense light beam to form particles that are directly coated onto a substrate surface. In preferred embodiments, a coating apparatus comprising a noncircular reactant inlet, optical elements forming a light path, a first substrate, and a motor connected to the apparatus. The reactant inlet defines a reactant stream path. The light path intersects the reactant stream path at a reaction zone with a product stream path continuing from the reaction zone. The substrate intersects the product stream path. Also, operation of the motor moves the first substrate relative to the product stream. Various broad methods are described for using light driven chemical reactions to produce efficiently highly uniform coatings.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: August 18, 2009
    Assignee: NanoGram Corporation
    Inventors: Xiangxin Bi, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, James T. Gardner, Seung M. Lim, William E. McGovern
  • Publication number: 20090081304
    Abstract: Milling approaches provide for the efficient formation of composite particles having an inorganic nanoparticle core with an organic coating composition. The nanoparticles can additionally function as a milling media or distinct milling particles can be used and later separated from the product composite particles. In general, the milling is performed in the presence of a dispersing agent that facilitates dispersing of the composite particles in a carrier liquid. The processes described herein can be effectively used in the formation of composite particles comprising organic pigments. Similarly, the composite particles can be formed with other organic compounds, such as organic pharmaceutical compositions.
    Type: Application
    Filed: September 21, 2007
    Publication date: March 26, 2009
    Inventors: Lye Han Valerie Choy, Shivkumar Chiruvolu, Nobuyuki Kambe, Vladimir K. Dioumaev, Hui Du, Shinichi Kuramoto, Hiroto Higuchi
  • Publication number: 20090075083
    Abstract: Methods are described that have the capability of producing submicron/nanoscale particles, in some embodiments dispersible, at high production rates. In some embodiments, the methods result in the production of particles with an average diameter less than about 75 nanometers that are produced at a rate of at least about 35 grams per hour. In other embodiments, the particles are highly uniform. These methods can be used to form particle collections and/or powder coatings. Powder coatings and corresponding methods are described based on the deposition of highly uniform submicron/nanoscale particles.
    Type: Application
    Filed: May 13, 2008
    Publication date: March 19, 2009
    Inventors: Xiangxin Bi, Nobuyuki Kambe, Craig R. Horne, James T. Gardner, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, William E. McGovern, Pierre J. DeMascarel, Robert B. Lynch
  • Patent number: 7491431
    Abstract: Methods for forming coated substrates can be based on depositing material from a flow onto a substrate in which the coating material is formed by a reaction within the flow. In some embodiments, the product materials are formed in a reaction driven by photon energy absorbed from a radiation beam. In additional or alternative embodiments, the flow with the product stream is directed at the substrate. The substrate may be moved relative to the flow. Coating materials can be formed with densities of 65 percent to 95 percent of the fully densified coating material with a very high level of coating uniformity.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: February 17, 2009
    Assignee: NanoGram Corporation
    Inventors: Shivkumar Chiruvolu, Michael Edward Chapin
  • Publication number: 20090017292
    Abstract: Sub-atmospheric pressure chemical vapor deposition is described with a directed reactant flow and a substrate that moves relative to the flow. Thus, using this CVD configuration a relatively high deposition rate can be achieved while obtaining desired levels of coating uniformity. Deposition approaches are described to place one or more inorganic layers onto a release layer, such as a porous, particulate release layer. In some embodiments, the release layer is formed from a dispersion of submicron particles that are coated onto a substrate. The processes described can be effective for the formation of silicon films that can be separated with the use of a release layer into a silicon foil. The silicon foils can be used for the formation of a range of semiconductor based devices, such as display circuits or solar cells.
    Type: Application
    Filed: June 12, 2008
    Publication date: January 15, 2009
    Inventors: Henry Hieslmair, Ronald J. Mosso, Narayan Solayappan, Shivkumar Chiruvolu, Julio E. Morris
  • Publication number: 20080199687
    Abstract: Functional composite materials comprise elemental inorganic particles within an organic matrix. The elemental inorganic materials generally comprise elemental metal, elemental metalloid, alloys thereof, or mixtures thereof. In alternative or additional embodiments, the inorganic particles can comprise a metal oxide, a metalloid oxide, a combination thereof or a mixture thereof. The inorganic particles can have an average primary particle size of no more than abut 250 nm and a secondary particle size in a dispersion when blended with the organic matrix of no more than about 2 microns. The particles can be substantially unagglomerated within the composite. The organic binder can be a functional polymer such as a semiconducting polymer. The inorganic particles can be surface modified, such as with a moiety having an aromatic functional group for desirable interactions with a semiconducting polymer. Appropriate solution based methods can be used for forming the composite from dispersions of the particles.
    Type: Application
    Filed: February 14, 2008
    Publication date: August 21, 2008
    Inventors: Shivkumar Chiruvolu, Vladimir K. Dioumaev, Nobuyuki Kambe, Hui Du
  • Publication number: 20080160733
    Abstract: Highly uniform silica nanoparticles can be formed into stable dispersions with a desirable small secondary particle size. The silican particles can be surface modified to form the dispersions. The silica nanoparticles can be doped to change the particle properties and/or to provide dopant for subsequent transfer to other materials. The dispersions can be printed as an ink for appropriate applications. The dispersions can be used to selectively dope semiconductor materials such as for the formation of photovoltaic cells or for the formation of printed electronic circuits.
    Type: Application
    Filed: January 2, 2008
    Publication date: July 3, 2008
    Inventors: Henry Hieslmair, Shivkumar Chiruvolu, Hui Du
  • Publication number: 20080160265
    Abstract: Highly uniform silicon/germanium nanoparticles can be formed into stable dispersions with a desirable small secondary particle size. The silicon/germanium particles can be surface modified to form the dispersions. The silicon/germanium nanoparticles can be doped to change the particle properties. The dispersions can be printed as an ink for appropriate applications. The dispersions can be used to form selectively doped deposits of semiconductor materials such as for the formation of photovoltaic cells or for the formation of printed electronic circuits.
    Type: Application
    Filed: January 2, 2008
    Publication date: July 3, 2008
    Inventors: Henry Hieslmair, Vladimir K. Dioumaev, Shivkumar Chiruvolu, Hui Du
  • Publication number: 20080150184
    Abstract: Successful dispersion approaches are described for the formation of dispersion of dry powders of inorganic particles. In some embodiments, it is desirable to form the dispersion in two processing steps in which the particles are surface modified in the second processing step. Composites can be formed using the well dispersed particles to form improved inorganic particle-polymer composites. These composites are suitable for optical applications and for forming transparent films, which can have a relatively high index or refraction. In some embodiments, water can be used to alter the surface chemistry of metal oxide particles.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 26, 2008
    Inventors: Shivkumar Chiruvolu, Hui Du, Nobuyuki Kambe
  • Publication number: 20080145641
    Abstract: Hollow silica nanoparticles can have well defined non-porous shells with low shell fragmentation and good dispersability. These well defined hollow particles can be formed through the controlled oxidation of silicon nanoparticles in an organic solvent. The hollow nanoparticles can have a submicron secondary particle sizes. The hollow silica nanoparticles can be incorporated into polymer composites, such as low index-of-refraction composites, for appropriate applications.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 19, 2008
    Inventors: Weidong Li, Shivkumar Chiruvolu, Hui Du, Igor Altman, Ronald J. Mosso, Nobuyuki Kambe