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).
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Publication number: 20250118810Abstract: Described herein are thermoelectrochemical cells which have high Seebeck coefficients, as well as various implementations for said thermoelectrochemical cells. For instance, in some embodiments, the presently described thermoelectrochemical cell may be used to convert low grade heat into electrical energy. In some embodiments, the output electrical energy may have an oscillatory nature. The magnitude of the output energy and the characteristics of the oscillations may be tuned by adjusting electrode pore sizes, thermoelectrochemical cell temperature gradient and the material of at least one of the electrode, electrolyte and separator.Type: ApplicationFiled: October 4, 2024Publication date: April 10, 2025Inventors: Apparao M. Rao, Basanta Ghimire, Mihir Parekh, Nawraj Sapkota, Morteza Sabet, Herbert Behlow, Sriparna Bhattacharya, Abha Misra, Pankaj Singh Chauhan
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Patent number: 11840454Abstract: 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: GrantFiled: November 12, 2021Date of Patent: December 12, 2023Assignee: CLEMSON UNIVERSITYInventors: Srikanth Pilla, Morteza Sabet, Apparao M. Rao, Nancy Chen
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Patent number: 11630007Abstract: 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: GrantFiled: June 23, 2020Date of Patent: April 18, 2023Assignee: Clemson UniversityInventors: Soaram Kim, Goutam Koley, Yongchang Dong, Apparao M. Rao
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Publication number: 20220153597Abstract: 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: ApplicationFiled: November 12, 2021Publication date: May 19, 2022Inventors: SRIKANTH PILLA, MORTEZA SABET, APPARAO M. RAO, NANCY CHEN
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Patent number: 11114955Abstract: 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: GrantFiled: November 16, 2018Date of Patent: September 7, 2021Assignee: Clemson UniversityInventors: Sai Sunil Kumar Mallineni, Herbert W. Behlow, Yongchang Dong, Ramakrishna Podila, Apparao M. Rao
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Publication number: 20200400514Abstract: 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: ApplicationFiled: June 23, 2020Publication date: December 24, 2020Inventors: SOARAM KIM, GOUTAM KOLEY, YONGCHANG DONG, APPARAO M. RAO
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Publication number: 20190157992Abstract: 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: ApplicationFiled: November 16, 2018Publication date: May 23, 2019Inventors: SAI SUNIL KUMAR MALLINENI, HERBERT W. BEHLOW, YONGCHANG DONG, RAMAKRISHNA PODILA, APPARAO M. RAO
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Patent number: 9552929Abstract: 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: GrantFiled: July 15, 2014Date of Patent: January 24, 2017Assignee: CLEMSON UNIVERSITYInventors: Mark E. Roberts, Apparao M. Rao, Ramakrishna Podila, Robert Emmett
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Publication number: 20150017528Abstract: 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: ApplicationFiled: July 15, 2014Publication date: January 15, 2015Inventors: Mark E. Roberts, Apparao M. Rao, Ramakrishna Podila, Robert Emmett
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Patent number: 8384372Abstract: 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: GrantFiled: October 5, 2009Date of Patent: February 26, 2013Assignee: Clemson UniversityInventors: Herbert W. Behlow, Jr., Bevan C. Elliott, Gayatri D. Keskar, Doyl E. Dickel, Malcolm J. Skove, Apparao M. Rao
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Patent number: 7818816Abstract: 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: GrantFiled: October 1, 2008Date of Patent: October 19, 2010Assignee: Clemson University Research FoundationInventors: Jason B. Reppert, Jay B. Gaillard, Bevan C. Elliott, Doyl E. Dickel, M. Pinar Mengüc, Apparao M. Rao
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Patent number: 7754183Abstract: 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: GrantFiled: May 20, 2005Date of Patent: July 13, 2010Assignee: Clemson University Research FoundationInventors: Gayatri D. Keskar, Wei Wang, Apparao M. Rao
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Publication number: 20100015033Abstract: 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: ApplicationFiled: May 20, 2005Publication date: January 21, 2010Inventors: Gayatri D. Keskar, Wei Wang, Apparao M. Rao
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Patent number: 7598723Abstract: 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: GrantFiled: February 14, 2006Date of Patent: October 6, 2009Inventors: Jay Gaillard, Razvan Marian Ciocan, Malcolm Skove, Apparao M. Rao
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Publication number: 20090162277Abstract: 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: ApplicationFiled: November 3, 2006Publication date: June 25, 2009Applicant: Clemson UniversityInventors: Pu-Chun Ke, Yonnie Wu, Apparao M. Rao
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Patent number: 7456972Abstract: 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: GrantFiled: January 13, 2006Date of Patent: November 25, 2008Assignee: Clemson UniversityInventors: Pu-Chun Ke, Francesco Stellacci, Apparao M. Rao
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Publication number: 20080088845Abstract: 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: ApplicationFiled: January 13, 2006Publication date: April 17, 2008Inventors: Pu-Chun Ke, Francesco Stellacci, Apparao M. Rao
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Patent number: 7241479Abstract: 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: GrantFiled: August 22, 2003Date of Patent: July 10, 2007Assignee: Clemson UniversityInventors: Apparao M. Rao, Rahul Rao
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Patent number: 7153452Abstract: 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: GrantFiled: September 12, 2003Date of Patent: December 26, 2006Assignee: Clemson UniversityInventors: Amod A. Ogale, Dan D Edie, Apparao M. Rao
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Patent number: 7144563Abstract: 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: GrantFiled: April 22, 2004Date of Patent: December 5, 2006Assignee: Clemson UniversityInventors: Apparao M. Rao, Nicholas W. Gothard, Jay B. Gaillard