Patents by Inventor Sreeram Vaddiraju

Sreeram Vaddiraju 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: 20100255303
    Abstract: Processing of nanostructures, composite materials comprising nanostructures, and related systems and methods are described. In some embodiments, conformal coatings are applied to nanostructures.
    Type: Application
    Filed: December 3, 2009
    Publication date: October 7, 2010
    Applicant: Massachusetts Institute of Technology
    Inventors: Brian L. Wardle, Hulya Cebeci, Sreeram Vaddiraju, Karen K. Gleason
  • Patent number: 7713352
    Abstract: A process is provided to produce bulk quantities of nanowires in a variety of semiconductor materials. Thin films and droplets of low-melting metals such as gallium, indium, bismuth, and aluminum are used to dissolve and to produce nanowires. The dissolution of solutes can be achieved by using a solid source of solute and low-melting metal, or using a vapor phase source of solute and low-melting metal. The resulting nanowires range in size from 1 nanometer up to 1 micron in diameter and lengths ranging from 1 nanometer to several hundred nanometers or microns. This process does not require the use of metals such as gold and iron in the form of clusters whose size determines the resulting nanowire size. In addition, the process allows for a lower growth temperature, better control over size and size distribution, and better control over the composition and purity of the nanowire produced therefrom.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: May 11, 2010
    Assignee: University of Louisville Research Foundation, Inc.
    Inventors: Mahendra Kumar Sunkara, Shashank Sharma, Hari Chandrasekaran, Hongwei Li, Sreeram Vaddiraju
  • Patent number: 7591897
    Abstract: A process for the rapid synthesis of metal oxide nanoparticles at low temperatures and methods which facilitate the fabrication of long metal oxide nanowires. The method is based on treatment of metals with oxygen plasma. Using oxygen plasma at low temperatures allows for rapid growth unlike other synthesis methods where nanomaterials take a long time to grow. Density of neutral oxygen atoms in plasma is a controlling factor for the yield of nanowires. The oxygen atom density window differs for different materials. By selecting the optimal oxygen atom density for various materials the yield can be maximized for nanowire synthesis of the metal.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: September 22, 2009
    Assignee: University of Louisville Research Foundation, Inc.
    Inventors: Mahendra Kumar Sunkara, Sreeram Vaddiraju, Miran Mozetic, Uros Cvelbar
  • Publication number: 20070118938
    Abstract: A process for the rapid synthesis of metal oxide nanoparticles at low temperatures and methods which facilitate the fabrication of long metal oxide nanowires. The method is based on treatment of metals with oxygen plasma. Using oxygen plasma at low temperatures allows for rapid growth unlike other synthesis methods where nanomaterials take a long time to grow. Density of neutral oxygen atoms in plasma is a controlling factor for the yield of nanowires. The oxygen atom density window differs for different materials. By selecting the optimal oxygen atom density for various materials the yield can be maximized for nanowire synthesis of the metal.
    Type: Application
    Filed: March 20, 2006
    Publication date: May 24, 2007
    Inventors: Mahendra Sunkara, Sreeram Vaddiraju, Miran Mozetic, Uros Cvelbar
  • Publication number: 20070095276
    Abstract: A process is provided to produce bulk quantities of nanowires in a variety of semiconductor materials. Thin films and droplets of low-melting metals such as gallium, indium, bismuth, and aluminum are used to dissolve and to produce nanowires. The dissolution of solutes can be achieved by using a solid source of solute and low-melting metal, or using a vapor phase source of solute and low-melting metal. The resulting nanowires range in size from 1 nanometer up to 1 micron in diameter and lengths ranging from 1 nanometer to several hundred nanometers or microns. This process does not require the use of metals such as gold and iron in the form of clusters whose size determines the resulting nanowire size. In addition, the process allows for a lower growth temperature, better control over size and size distribution, and better control over the composition and purity of the nanowire produced therefrom.
    Type: Application
    Filed: September 14, 2006
    Publication date: May 3, 2007
    Inventors: Mahendra Sunkara, Shashank Sharma, Hari Chandrasekaran, Hongwei Li, Sreeram Vaddiraju
  • Publication number: 20070087470
    Abstract: Vapor phase methods for synthesizing metal nanowires directly without the help of templates. A vapor phase method in which nucleation and growth of metal oxides at temperatures higher than the oxide decomposition temperatures lead to the respective metal nanowires. The chemical vapor transport of tungsten in the presence of oxygen onto substrates kept at temperatures higher than the tungsten oxide decomposition temperature (˜1450° C.) led to nucleation and growth of pure metallic tungsten nanowires. In a similar procedure, tungsten oxide nanowires were synthesized by maintaining the substrates at a temperature lower than the decomposition temperature of tungsten oxide. The vapor transport of low-melting metal oxides provides a procedure for synthesizing metal and metal oxide nanowires.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 19, 2007
    Inventors: Mahendra Sunkara, Sreeram Vaddiraju, Biswapriya Deb, Jyothish Thangala