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).

  • Publication number: 20230364023
    Abstract: Methods for providing an inorganic oxide coating to high aspect ratio particles containing an active pharmaceutical ingredient are described as are compositions containing such coated particles.
    Type: Application
    Filed: May 19, 2023
    Publication date: November 16, 2023
    Inventors: Miaojun Wang, Jonathan Frankel, Pravin K. Narwankar, Suneel Kumar Rastogi, Shivkumar Chiruvolu, Fei Wang, Balaji Ganapathy, Shrikant Swaminathan
  • Publication number: 20210378971
    Abstract: A pharmaceutical composition containing a metal oxide coated particle comprising 1) an amorphous solid dispersion (ASD) core containing an active pharmaceutical ingredient (API) and a polymer; and 2) a metal oxide coating, and the method of making said metal oxide coated particle by atomic layer deposition (ALD). The metal oxide coated particle is useful because it prevents the ASD from crystallization and helps maintain the ASD in an amorphous form.
    Type: Application
    Filed: June 7, 2021
    Publication date: December 9, 2021
    Inventors: Fei Wang, Miaojun Wang, Balaji Ganapathy, Jonathan Frankel, Shivkumar Chiruvolu, Pravin K. Narwankar
  • Patent number: 9475695
    Abstract: Silicon based nanoparticle inks are formulated with viscous polycyclic alcohols to control the rheology of the inks. The inks can be formulated into pastes with non-Newtonian rheology and good screen printing properties. The inks can have low metal contamination such that they are suitable for forming semiconductor structures. The silicon based nanoparticles can be elemental silicon particles with or without dopant.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: October 25, 2016
    Assignee: NanoGram Corporation
    Inventors: Weidong Li, Masaya Soeda, Gina Elizabeth Pengra-Leung, Shivkumar Chiruvolu
  • Patent number: 9448331
    Abstract: Polymer-inorganic particle blends are incorporated into structures generally involving interfaces with additional materials that can be used advantageously for forming desirable devices. In some embodiments, the structures are optical structures, and the interfaces are optical interfaces. The different materials at the interface can have differences in index-of-refraction to yield desired optical properties at the interface. In some embodiments, structures are formed with periodic variations in index-of-refraction. In particular, photonic crystals can be formed. Suitable methods can be used to form the desired structures.
    Type: Grant
    Filed: March 2, 2015
    Date of Patent: September 20, 2016
    Assignee: NanoGram Corporation
    Inventors: Nobuyuki Kambe, Shivkumar Chiruvolu
  • Patent number: 9378957
    Abstract: The use of doped silicon nanoparticle inks and other liquid dopant sources can provide suitable dopant sources for driving dopant elements into a crystalline silicon substrate using a thermal process if a suitable cap is provided. Suitable caps include, for example, a capping slab, a cover that may or may not rest on the surface of the substrate and a cover layer. Desirable dopant profiled can be achieved. The doped nanoparticles can be delivered using a silicon ink. The residual silicon ink can be removed after the dopant drive-in or at least partially densified into a silicon material that is incorporated into the product device. The silicon doping is suitable for the introduction of dopants into crystalline silicon for the formation of solar cells.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: June 28, 2016
    Assignee: NanoGram Corporation
    Inventors: Guojun Liu, Uma Srinivasan, Shivkumar Chiruvolu
  • Patent number: 9163308
    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: Grant
    Filed: July 30, 2009
    Date of Patent: October 20, 2015
    Assignee: NanoGram Corporation
    Inventors: Xiangxin Bi, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, James T. Gardner, Seung M. Lim, William E. McGovern
  • Publication number: 20150191616
    Abstract: Laser pyrolysis reactor designs and corresponding reactant inlet nozzles are described to provide desirable particle quenching that is particularly suitable for the synthesis of elemental silicon particles. In particular, the nozzles can have a design to encourage nucleation and quenching with inert gas based on a significant flow of inert gas surrounding the reactant precursor flow and with a large inert entrainment flow effectively surrounding the reactant precursor and quench gas flows. Improved silicon nanoparticle inks are described that has silicon nanoparticles without any surface modification with organic compounds. The silicon ink properties can be engineered for particular printing applications, such as inkjet printing, gravure printing or screen printing. Appropriate processing methods are described to provide flexibility for ink designs without surface modifying the silicon nanoparticles.
    Type: Application
    Filed: March 20, 2015
    Publication date: July 9, 2015
    Inventors: Shivkumar Chiruvolu, Igor Altman, Bernard M. Frey, Weidong Li, Guojun Liu, Robert B. Lynch, Gina Elizabeth Pengra-Leung, Uma Srinivasan
  • Publication number: 20150168602
    Abstract: Polymer-inorganic particle blends are incorporated into structures generally involving interfaces with additional materials that can be used advantageously for forming desirable devices. In some embodiments, the structures are optical structures, and the interfaces are optical interfaces. The different materials at the interface can have differences in index-of-refraction to yield desired optical properties at the interface. In some embodiments, structures are formed with periodic variations in index-of-refraction. In particular, photonic crystals can be formed. Suitable methods can be used to form the desired structures.
    Type: Application
    Filed: March 2, 2015
    Publication date: June 18, 2015
    Inventors: Nobuyuki Kambe, Shivkumar Chiruvolu
  • Patent number: 9006720
    Abstract: Laser pyrolysis reactor designs and corresponding reactant inlet nozzles are described to provide desirable particle quenching that is particularly suitable for the synthesis of elemental silicon particles. In particular, the nozzles can have a design to encourage nucleation and quenching with inert gas based on a significant flow of inert gas surrounding the reactant precursor flow and with a large inert entrainment flow effectively surrounding the reactant precursor and quench gas flows. Improved silicon nanoparticle inks are described that has silicon nanoparticles without any surface modification with organic compounds. The silicon ink properties can be engineered for particular printing applications, such as inkjet printing, gravure printing or screen printing. Appropriate processing methods are described to provide flexibility for ink designs without surface modifying the silicon nanoparticles.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: April 14, 2015
    Assignee: NanoGram Corporation
    Inventors: Shivkumar Chiruvolu, Igor Altman, Bernard M. Frey, Weidong Li, Guojun Liu, Robert B. Lynch, Gina Elizabeth Pengra-Leung, Uma Srinivasan
  • Patent number: 8912083
    Abstract: The use of doped silicon nanoparticle inks and other liquid dopant sources can provide suitable dopant sources for driving dopant elements into a crystalline silicon substrate using a thermal process if a suitable cap is provided. Suitable caps include, for example, a capping slab, a cover that may or may not rest on the surface of the substrate and a cover layer. Desirable dopant profiled can be achieved. The doped nanoparticles can be delivered using a silicon ink. The residual silicon ink can be removed after the dopant drive-in or at least partially densified into a silicon material that is incorporated into the product device. The silicon doping is suitable for the introduction of dopants into crystalline silicon for the formation of solar cells.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: December 16, 2014
    Assignee: NanoGram Corporation
    Inventors: Guojun Liu, Uma Srinivasan, Shivkumar Chiruvolu
  • Publication number: 20140346436
    Abstract: Silicon based nanoparticle inks are formulated with viscous polycyclic alcohols to control the rheology of the inks. The inks can be formulated into pastes with non-Newtonian rheology and good screen printing properties. The inks can have low metal contamination such that they are suitable for forming semiconductor structures. The silicon based nanoparticles can be elemental silicon particles with or without dopant.
    Type: Application
    Filed: May 20, 2014
    Publication date: November 27, 2014
    Applicant: NanoGram Corporation
    Inventors: Weidong Li, Masaya Soeda, Gina Elizabeth Pengra-Leung, Shivkumar Chiruvolu
  • Patent number: 8895962
    Abstract: Laser pyrolysis reactor designs and corresponding reactant inlet nozzles are described to provide desirable particle quenching that is particularly suitable for the synthesis of elemental silicon particles. In particular, the nozzles can have a design to encourage nucleation and quenching with inert gas based on a significant flow of inert gas surrounding the reactant precursor flow and with a large inert entrainment flow effectively surrounding the reactant precursor and quench gas flows. Improved silicon nanoparticle inks are described that has silicon nanoparticles without any surface modification with organic compounds. The silicon ink properties can be engineered for particular printing applications, such as inkjet printing, gravure printing or screen printing. Appropriate processing methods are described to provide flexibility for ink designs without surface modifying the silicon nanoparticles.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: November 25, 2014
    Assignee: NanoGram Corporation
    Inventors: Shivkumar Chiruvolu, Igor Altman, Bernard M. Frey, Weidong Li, Guojun Liu, Robert B. Lynch, Gina Elizabeth Pengra-Leung, Uma Srinivasan
  • Publication number: 20140162445
    Abstract: The use of doped silicon nanoparticle inks and other liquid dopant sources can provide suitable dopant sources for driving dopant elements into a crystalline silicon substrate using a thermal process if a suitable cap is provided. Suitable caps include, for example, a capping slab, a cover that may or may not rest on the surface of the substrate and a cover layer. Desirable dopant profiled can be achieved. The doped nanoparticles can be delivered using a silicon ink. The residual silicon ink can be removed after the dopant drive-in or at least partially densified into a silicon material that is incorporated into the product device. The silicon doping is suitable for the introduction of dopants into crystalline silicon for the formation of solar cells.
    Type: Application
    Filed: February 14, 2014
    Publication date: June 12, 2014
    Applicant: NanoGram Corporation
    Inventors: Guojun Liu, Uma Srinivasan, Shivkumar Chiruvolu
  • Publication number: 20140151706
    Abstract: Silicon nanoparticle inks provide a basis for the formation of desirable materials. Specifically, composites have been formed in thin layers comprising silicon nanoparticles embedded in an amorphous silicon matrix, which can be formed at relatively low temperatures. The composite material can be heated to form a nanocrystalline material having crystals that are non-rod shaped. The nanocrystalline material can have desirable electrical conductive properties, and the materials can be formed with a high dopant level. Also, nanocrystalline silicon pellets can be formed from silicon nanoparticles deposited form an ink in which the pellets can be relatively dense although less dense than bulk silicon. The pellets can be formed from the application of pressure and heat to a silicon nanoparticle layer.
    Type: Application
    Filed: February 7, 2014
    Publication date: June 5, 2014
    Applicant: NanoGram Corporation
    Inventors: Guojun Liu, Shivkumar Chiruvolu, Weidong Li, Uma Srinivasan
  • Publication number: 20140138135
    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: December 31, 2013
    Publication date: May 22, 2014
    Applicant: NanoGram Corporation
    Inventors: Henry Hieslmair, Vladimir K. Dioumaev, Shivkumar Chiruvolu, Hui Du
  • Patent number: 8673407
    Abstract: Three dimensional optical structures are described that can have various integrations between optical devices within and between layers of the optical structure. Optical turning elements can provide optical pathways between layers of optical devices. Methods are described that provide for great versatility on contouring optical materials throughout the optical structure. Various new optical devices are enabled by the improved optical processing approaches.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: March 18, 2014
    Assignee: NeoPhotonics Corporation
    Inventors: Xiangxin Bi, Elizabeth Anne Nevis, Ronald J. Mosso, Michael Edward Chapin, Shivkumar Chiruvolu, Sardar Hyat Khan, Sujeet Kumar, Herman Adrian Lopez, Nguyen Tran The Huy, Craig Richard Horne, Michael A. Bryan, Eric Euvrard
  • Patent number: 8658726
    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: Grant
    Filed: March 18, 2013
    Date of Patent: February 25, 2014
    Assignee: NanoGram Corporation
    Inventors: Hui Du, Shivkumar Chiruvolu, Ang-Ling Chu
  • Patent number: 8632702
    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: Grant
    Filed: January 2, 2008
    Date of Patent: January 21, 2014
    Assignee: NanoGram Corporation
    Inventors: Henry Hieslmair, Vladimir K. Dioumaev, Shivkumar Chiruvolu, Hui Du
  • Patent number: 8568684
    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: Grant
    Filed: January 13, 2010
    Date of Patent: October 29, 2013
    Assignee: NanoGram Corporation
    Inventors: Xiangxin Bi, Nobuyuki Kambe, James T. Gardner, Ronald J. Mosso, Shivkumar Chiruvolu, Sujeet Kumar, William E. McGovern
  • Publication number: 20130189831
    Abstract: Improved silicon/germanium nanoparticle inks are described that have silicon/germanium nanoparticles well distributed within a stable dispersion. In particular the inks are formulated with a centrifugation step to remove contaminants as well as less well dispersed portions of the dispersion. A sonication step can be used after the centrifugation, which is observed to result in a synergistic improvement to the quality of some of the inks. The silicon/germanium ink properties can be engineered for particular deposition applications, such as spin coating or screen printing. Appropriate processing methods are described to provide flexibility for ink designs without surface modifying the silicon/germanium nanoparticles. The silicon/germanium nanoparticles are well suited for forming semiconductor components, such as components for thin film transistors or solar cell contacts.
    Type: Application
    Filed: January 19, 2012
    Publication date: July 25, 2013
    Inventors: Weidong Li, Gina Elizabeth Pengra-Leung, Uma Srinivasan, Shivkumar Chiruvolu, Masaya Soeda, Guojon Liu