Patents by Inventor Apparao M. Rao

Apparao M. Rao 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: 11840454
    Abstract: Methods for synthesis of high surface area porous silicon-based materials and structures that can be formed according to the methods are described. Methods are scalable and capable of producing large quantities of the high surface area materials with high efficiency. The high surface area products can be in the form of a 3D network of interconnected arms or quills with multimodal porosity including high level pores between and among arms, hollow cores of the arms of the network, and pores through the walls of the arms of the network.
    Type: Grant
    Filed: November 12, 2021
    Date of Patent: December 12, 2023
    Assignee: CLEMSON UNIVERSITY
    Inventors: Srikanth Pilla, Morteza Sabet, Apparao M. Rao, Nancy Chen
  • Patent number: 11630007
    Abstract: Pressure/strain piezoresistive are described that include a poled piezoelectric polymer such as PVDF or P(VDF-TrFE) and graphene. The poled piezoelectric polymer and the graphene are electronically coupled to form a heterojunction and provide an ultra-high sensitivity pressure/strain sensor. The sensors can be carried on a flexible supporting substrate such as PDMS or PET to exhibit high flexibility. The materials of formation can be biocompatible and the sensors can be wearable or implantable.
    Type: Grant
    Filed: June 23, 2020
    Date of Patent: April 18, 2023
    Assignee: Clemson University
    Inventors: Soaram Kim, Goutam Koley, Yongchang Dong, Apparao M. Rao
  • Publication number: 20220153597
    Abstract: Methods for synthesis of high surface area porous silicon-based materials and structures that can be formed according to the methods are described. Methods are scalable and capable of producing large quantities of the high surface area materials with high efficiency. The high surface area products can be in the form of a 3D network of interconnected arms or quills with multimodal porosity including high level pores between and among arms, hollow cores of the arms of the network, and pores through the walls of the arms of the network.
    Type: Application
    Filed: November 12, 2021
    Publication date: May 19, 2022
    Inventors: SRIKANTH PILLA, MORTEZA SABET, APPARAO M. RAO, NANCY CHEN
  • Patent number: 11114955
    Abstract: Devices and methods relate to a portable self-powered wireless sensor and transmitter providing a tactile driven electric generator, using a 3D printed nano carbon and polymer electrodes. The device has two electrodes capable of producing greater than 2000 V, which when connected to a metal conductor is sufficient to create an electric field that can be used to wirelessly communicate a signal over a range of a few tens of meters. The sensor is completely self-powered and requires no motors or additional power such as active power supplies, batteries, or capacitors. The sensor generated waveform can be modulated by mechanical action such as hand tapping in a given sequence, which is preserved in the wireless signal (akin to Morse coding) and can be detected by existing compatible commercial electronic receivers. Resulting devices are suitable for security applications requiring wireless transmission of codes.
    Type: Grant
    Filed: November 16, 2018
    Date of Patent: September 7, 2021
    Assignee: Clemson University
    Inventors: Sai Sunil Kumar Mallineni, Herbert W. Behlow, Yongchang Dong, Ramakrishna Podila, Apparao M. Rao
  • Publication number: 20200400514
    Abstract: Pressure/strain piezoresistive are described that include a poled piezoelectric polymer such as PVDF or P(VDF-TrFE) and graphene. The poled piezoelectric polymer and the graphene are electronically coupled to form a heterojunction and provide an ultra-high sensitivity pressure/strain sensor. The sensors can be carried on a flexible supporting substrate such as PDMS or PET to exhibit high flexibility. The materials of formation can be biocompatible and the sensors can be wearable or implantable.
    Type: Application
    Filed: June 23, 2020
    Publication date: December 24, 2020
    Inventors: SOARAM KIM, GOUTAM KOLEY, YONGCHANG DONG, APPARAO M. RAO
  • Publication number: 20190157992
    Abstract: Devices and methods relate to a portable self-powered wireless sensor and transmitter providing a tactile driven electric generator, using a 3D printed nano carbon and polymer electrodes. The device has two electrodes capable of producing greater than 2000 V, which when connected to a metal conductor is sufficient to create an electric field that can be used to wirelessly communicate a signal over a range of a few tens of meters. The sensor is completely self-powered and requires no motors or additional power such as active power supplies, batteries, or capacitors. The sensor generated waveform can be modulated by mechanical action such as hand tapping in a given sequence, which is preserved in the wireless signal (akin to Morse coding) and can be detected by existing compatible commercial electronic receivers. Resulting devices are suitable for security applications requiring wireless transmission of codes.
    Type: Application
    Filed: November 16, 2018
    Publication date: May 23, 2019
    Inventors: SAI SUNIL KUMAR MALLINENI, HERBERT W. BEHLOW, YONGCHANG DONG, RAMAKRISHNA PODILA, APPARAO M. RAO
  • Patent number: 9552929
    Abstract: Embodiments of the present disclosure, in one aspect, relate to composites including a carbon nanomaterial having a redox-active material, such as a polymer containing redox groups, disposed on the carbon nanomaterial, methods of making the composite, methods of storing energy, and the like.
    Type: Grant
    Filed: July 15, 2014
    Date of Patent: January 24, 2017
    Assignee: CLEMSON UNIVERSITY
    Inventors: Mark E. Roberts, Apparao M. Rao, Ramakrishna Podila, Robert Emmett
  • Publication number: 20150017528
    Abstract: Embodiments of the present disclosure, in one aspect, relate to composites including a carbon nanomaterial having a redox-active material, such as a polymer containing redox groups, disposed on the carbon nanomaterial, methods of making the composite, methods of storing energy, and the like.
    Type: Application
    Filed: July 15, 2014
    Publication date: January 15, 2015
    Inventors: Mark E. Roberts, Apparao M. Rao, Ramakrishna Podila, Robert Emmett
  • Patent number: 8384372
    Abstract: A method and system is disclosed to detect and analyze an electric signal based on movement between an element and a counter electrode influenced by a nonlinear electric field produced by an electrical signal impressed between the element and counter electrode. Through detection of changes in the distance between the element and the counter electrode characteristics of the element and/or the environment of the element may be ascertained. Changes in the distance between the element and the counter electrode may be monitored based on changes in the value of capacitance between the element and counter electrode. The disclosed devices and methods may be employed to detect, for instance, presence of chemical/biological species in a sample or measure physical parameters of a sample such as pressure/acceleration, density, viscosity, magnetic force, temperature, and/or extremely small masses.
    Type: Grant
    Filed: October 5, 2009
    Date of Patent: February 26, 2013
    Assignee: Clemson University
    Inventors: Herbert W. Behlow, Jr., Bevan C. Elliott, Gayatri D. Keskar, Doyl E. Dickel, Malcolm J. Skove, Apparao M. Rao
  • Patent number: 7818816
    Abstract: Disclosed are methods and devices for patterning micro- and/or nano-sized pattern elements on a substrate using field emitted electrons from an element. Disclosed methods and devices can also be utilized to form nano- and micron-sized depressions in a substrate according to a more economical process than as has been utilized in the past. Methods include single-step methods by which structures can be simultaneously created and located at desired locations on a substrate. Methods include the application of a bias voltage between a probe tip and a substrate held at a relatively close gap distance. The applied voltage can promote current flow between the probe and the substrate via field emissions. During a voltage pulse, and within predetermined energy levels and tip-to-surface gap distances, three dimensional formations can be developed on the substrate surface.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: October 19, 2010
    Assignee: Clemson University Research Foundation
    Inventors: Jason B. Reppert, Jay B. Gaillard, Bevan C. Elliott, Doyl E. Dickel, M. Pinar Mengüc, Apparao M. Rao
  • Patent number: 7754183
    Abstract: The present invention discloses a relatively simple CVD method for forming specifically tailored carbon-based nanostructures. In general, the method is a chemical vapor deposition method in which at least a portion of the precursor materials are provided as a liquid at atmospheric conditions. The precursor materials include at least one carbon source and at least one catalyst source. Optionally, the precursor materials can also include one or more dopant sources. The carbon source and the optional dopant source can be injected as liquids into the system, and the liquid catalyst source can be either injected into the system or located on a substrate in the reactor prior to the process. Very high yield of nanostructures exhibiting particular characteristics can be attained by the process.
    Type: Grant
    Filed: May 20, 2005
    Date of Patent: July 13, 2010
    Assignee: Clemson University Research Foundation
    Inventors: Gayatri D. Keskar, Wei Wang, Apparao M. Rao
  • Publication number: 20100015033
    Abstract: The present invention discloses a relatively simple CVD method for forming specifically tailored carbon-based nanostructures. In general, the method is a chemical vapor deposition method in which at least a portion of the precursor materials are provided as a liquid at atmospheric conditions. The precursor materials include at least one carbon source and at least one catalyst source. Optionally, the precursor materials can also include one or more dopant sources. The carbon source and the optional dopant source can be injected as liquids into the system, and the liquid catalyst source can be either injected into the system or located on a substrate in the reactor prior to the process. Very high yield of nanostructures exhibiting particular characteristics can be attained by the process.
    Type: Application
    Filed: May 20, 2005
    Publication date: January 21, 2010
    Inventors: Gayatri D. Keskar, Wei Wang, Apparao M. Rao
  • Patent number: 7598723
    Abstract: A method and system is disclosed that can be used to directly detect and analyze an electric signal electrostatically induced a semi-conductive or conductive element at resonance. Through detection of the changes in the characteristics of the signal from the element, the disclosed devices can detect, for instance, presence of chemical/biological species in a sample or measure physical parameters of a sample such as pressure/acceleration, magnetic force, temperature, and/or extremely small masses. The disclosed systems include one or more micro- or nano-sized elements. Through modulation of an electric charge on a counter-electrode that is located at a pre-determined distance from the element, a modulating charge can be induced upon the element. Resonance can be directly detected via electronic monitoring of the induced signal for the higher harmonics of the natural resonant frequency.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: October 6, 2009
    Inventors: Jay Gaillard, Razvan Marian Ciocan, Malcolm Skove, Apparao M. Rao
  • Publication number: 20090162277
    Abstract: Lipophilic compounds extracted from cell growth mediums, particularly lysophospholipids are used to solubilize single-walled nanotubes. The naturally occurring lysophospholipids were found to readily bond to the exterior wall of the single-walled nanotubes to enhance the biocompatibility of the single-walled nanotubes in therapeutic and diagnostic conditions. The solubilization protocol is simple, highly efficient, and results in a population of coated single-walled nanotubes which are highly stable.
    Type: Application
    Filed: November 3, 2006
    Publication date: June 25, 2009
    Applicant: Clemson University
    Inventors: Pu-Chun Ke, Yonnie Wu, Apparao M. Rao
  • Patent number: 7456972
    Abstract: Disclosed are optical devices including one or more carbon nanotubes that can function as plasmon waveguides. The presently disclosed devices advantageously utilize the existence of surface plasmons on carbon nanotubes through the generation and transport of surface plasmon polaritons across the nanotubes. Also disclosed are methods for tuning the devices through particular formation parameters for the nanotubes and/or selection of particular substrate materials. Systems of the present invention can provide optical data concerning a sample, for instance via construction of an NSOM image, as well as topological date concerning a sample via construction of an AFM image. In one embodiment, the disclosed systems can provide simultaneous acquisition of optical images and topological images.
    Type: Grant
    Filed: January 13, 2006
    Date of Patent: November 25, 2008
    Assignee: Clemson University
    Inventors: Pu-Chun Ke, Francesco Stellacci, Apparao M. Rao
  • Publication number: 20080088845
    Abstract: Disclosed are optical devices including one or more carbon nanotubes that can function as plasmon waveguides. The presently disclosed devices advantageously utilize the existence of surface plasmons on carbon nanotubes through the generation and transport of surface plasmon polaritons across the nanotubes. Also disclosed are methods for tuning the devices through particular formation parameters for the nanotubes and/or selection of particular substrate materials. Systems of the present invention can provide optical data concerning a sample, for instance via construction of an NSOM image, as well as topological date concerning a sample via construction of an AFM image. In one embodiment, the disclosed systems can provide simultaneous acquisition of optical images and topological images.
    Type: Application
    Filed: January 13, 2006
    Publication date: April 17, 2008
    Inventors: Pu-Chun Ke, Francesco Stellacci, Apparao M. Rao
  • Patent number: 7241479
    Abstract: The present invention is generally directed to a novel process for the production of nanowires and nanobelts and the novel nanostructures which can be produced according to the disclosed processes. The process can be carried out at ambient pressure and includes locating a metal in a reaction chamber, heating the chamber to a temperature at which the metal becomes molten, and flowing a vapor-phase reactant through the chamber. The vapor-phase reactant and the molten metal can react through a thermal CVD process, and nanostructures can form on the surface of the molten metal. Dimensions of the nanostructures can be controlled by reaction temperature.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: July 10, 2007
    Assignee: Clemson University
    Inventors: Apparao M. Rao, Rahul Rao
  • Patent number: 7153452
    Abstract: A modified, mesophase pitch-based carbon fiber is disclosed which includes carbon nanotube reinforcements in an amount ranging from about 0.01 percent to about 1.0 percent by weight. Although the reinforcements actually decrease the excellent tensile modulus of the unmodified fiber, they provide a random microstructure, which can decrease brittle failure of the fiber caused by propagation of a flaw.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: December 26, 2006
    Assignee: Clemson University
    Inventors: Amod A. Ogale, Dan D Edie, Apparao M. Rao
  • Patent number: 7144563
    Abstract: The present invention discloses a relatively simple CVD method for forming branched carbon nanotubes. In general, the method includes adding a dopant to the precursor materials. The dopant can be a material that has a thermodynamically more favorable carbide-forming reaction at the reactor conditions than does the catalyst that is provided to the reactor by a second precursor material. The doped nanoparticles formed in the reactor can adhere to the walls of the developing nanotubes and provide a nucleation site for the development of one or more branches on the nanotube. The nanotubes formed according to the invention can be recognized as such due to the presence of the doped nanoparticles adhered along the walls of the branched nanotubes.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: December 5, 2006
    Assignee: Clemson University
    Inventors: Apparao M. Rao, Nicholas W. Gothard, Jay B. Gaillard
  • Patent number: 6997039
    Abstract: Disclosed are resonant gas sensors and methods for forming and using the disclosed sensors. The sensors include a resonator including a layer comprising adsorptive nanostructures, for example carbon nanotubes, activated carbon fibers, or adsorptive nanowires. The dielectric of the resonator is in electrical communication with the layer comprising adsorptive nanostructures such that the effective resonant frequency of the resonator depends on both the dielectric constant of the dielectric as well as the dielectric constant of the adsorptive layer. In some embodiments, the nanostructures can be degassed. The sensors can detect the presence of polar gases, non-polar gases, organic vapors, and mixtures of materials with both high sensitivity and high selectivity.
    Type: Grant
    Filed: February 24, 2004
    Date of Patent: February 14, 2006
    Assignee: Clemson University
    Inventors: Apparao M. Rao, Saurabh Chopra