Patents by Inventor Shriram Ramanathan

Shriram Ramanathan 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: 20210255518
    Abstract: An electrochromic system is disclosed which includes a first glass layer having a bottom side and a top side, the top side coated with a first transparent conductor layer, an electrolyte layer formed adjacent to the first transparent conductor layer, an electrochromic layer formed adjacent to the electrolyte layer, and a second glass layer having a top side and a bottom side, the bottom side coated with a second transparent conductor layer and coupled to the electrochromic layer.
    Type: Application
    Filed: August 7, 2019
    Publication date: August 19, 2021
    Applicant: Purdue Research Foundation
    Inventors: YIFEI SUN, Shriram Ramanathan
  • Patent number: 10600959
    Abstract: Reversible phase transitions of exceptional magnitude may be induced in correlated metal oxides by altering their chemical compositions through reversible introduction of dopant ions and electronic carriers into the correlated metal oxides. One or more catalyst electrodes may be deposited onto a surface of a film of a correlated metal oxide such as a perovskite or a transition metal oxide. Dopant ions and electronic carriers may be electrochemically introduced into the catalyst-deposited correlated metal oxide, for example by annealing the catalyst-deposited film of correlated metal oxide in a chamber containing the dopant molecules. In this way, a reversible phase transition of about five to eight orders of magnitude may be induced.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: March 24, 2020
    Assignee: President and Fellows of Harvard College
    Inventors: Jian Shi, You Zhou, Shriram Ramanathan
  • Publication number: 20200025966
    Abstract: An electric field sensing device. The device includes a substrate, a sensing medium capable of experiencing a change in its electrical resistivity in response to an electric field, and electrodes for use in measuring the change. A method of making an electric field sensing device. The method includes depositing on a substrate a sensing medium capable of experiencing a change in its electrical resistivity in response to an electric field emitted by an object; and placing electrodes for use in measuring the change. An electric field sensing system. The system contains a plurality electric field sensing devices, an arrangement of the plurality sensing devices in a way to detect spatial variation of electric field emitted by objects in an environment; a computer system capable of monitoring the sensing devices, and detecting and comparing differences between the electrical fields sensed by individual devices.
    Type: Application
    Filed: October 8, 2018
    Publication date: January 23, 2020
    Applicant: Purdue Research Foundation
    Inventors: Shriram Ramanathan, Zhen Zhang, Derek Karl Schwanz
  • Publication number: 20190140312
    Abstract: A solid-state ionic conductor. The solid-state ionic conductor contains a correlated perovskite into which ions and electrons are inserted giving rise to ionic conductivity. The inserted ions occupy interstitial lattice sites of the correlated perovskite, reduce the electronic conductivity of the correlated perovskite. A method of producing a solid-state ionic conductor. The method includes forming a thin film containing a transition metal X, a rare earth element R and oxygen (O) by co-depositing the transition metal and the rare earth element on a substrate in an oxygen-containing atmosphere. The thin film is then annealed at an annealing temperature for a period of time in an oxygen containing atmosphere, resulting in formation of a crystalline film of RXO3. Ions and electrons from an ion source are then inserted into the crystalline film of RXO3, resulting in a solid-state ionic conductor.
    Type: Application
    Filed: November 1, 2018
    Publication date: May 9, 2019
    Applicant: Purdue Research Foundation
    Inventors: Shriram Ramanathan, Yifei Sun
  • Publication number: 20180190436
    Abstract: Phase change materials such as correlated oxides (e.g., such as NbO2, V2O3 and VO2) enable wide tuning of dielectric properties via control of temperature, electric fields, optical fields or disorder. The distinct dielectric states can be volatile or non-volatile depending on how the phase is created. Possible fabrication techniques for oxide and insulating matrix composites may include sequential/co-deposition routes as well as local controlled disorder. By combining the distinct insulating and metallic states in these systems and by control of the ground state via induced defects, artificial electronic composites, whose properties can be tuned, could be manufactured. The composites can be integral components of coplanar waveguide devices and microwave switches. More broadly, tunable electronic composites using oxide systems that undergo insulator-metal transitions may have wide usage in frequency tunable devices, including microwave devices.
    Type: Application
    Filed: December 29, 2017
    Publication date: July 5, 2018
    Inventors: Amy Elizabeth Duwel, Douglas W. White, Shriram Ramanathan, Jacob P. Treadway
  • Patent number: 9755245
    Abstract: A method of forming a catalyst material includes coating agglomerates of catalyst support particles with an ionomer material. After coating the agglomerates of catalyst support particles, a catalyst metal precursor is deposited by chemical infiltration onto peripheral surfaces of the agglomerates of catalyst support particles. The catalyst metal precursor is then chemically reduced to form catalyst metal on the peripheral surfaces of the agglomerates of catalyst support particles.
    Type: Grant
    Filed: April 25, 2011
    Date of Patent: September 5, 2017
    Assignee: Audi AG
    Inventors: Shriram Ramanathan, Laura Roen Stolar
  • Patent number: 9620803
    Abstract: A solid oxide fuel cell has a reinforced membrane-electrode assembly. The solid oxide fuel cell includes a first electrode layer, a second electrode layer, and an electrolyte membrane disposed between the first and second electrode layers. The solid oxide fuel cell further includes a gas-permeable structure adjacent to one or both of the electrode layers, for mechanical stabilization.
    Type: Grant
    Filed: March 11, 2015
    Date of Patent: April 11, 2017
    Assignee: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Shriram Ramanathan, Alexander C. Johnson
  • Patent number: 9515256
    Abstract: Phase transition devices may include a functional layer made of functional material that can undergo a change in conductance in response to an external stimulus such as an electric or magnetic or optical field, or heat. The functional material transitions between a conducting state and a non-conducting state, upon application of the external stimulus. A capacitive device may include a functional layer between a top electrode and a bottom electrode, and a dielectric layer between the functional layer and the top electrode. A three terminal phase transition switch may include a functional layer, for example a conductive oxide channel, deposited between a source and a drain, and a gate dielectric layer and a gate electrode deposited on the functional layer. An array of phase transition switches and/or capacitive devices may be formed on a substrate, which may be made of inexpensive flexible material.
    Type: Grant
    Filed: August 3, 2015
    Date of Patent: December 6, 2016
    Assignee: PRESIDENTS AND FELLOWS OF HARVARD COLLEGE
    Inventors: Shriram Ramanathan, Dmitry Ruzmetov, Venkatesh Narayanamurti, Changhyun Ko
  • Patent number: 9508675
    Abstract: A method of fabricating a microelectronic package having a direct contact heat spreader, a package formed according to the method, a die-heat spreader combination formed according to the method, and a system incorporating the package. The method comprises metallizing a backside of a microelectronic die to form a heat spreader body directly contacting and fixed to the backside of the die thus yielding a die-heat spreader combination. The package includes the die-heat spreader combination and a substrate bonded to the die.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: November 29, 2016
    Assignee: Intel Corporation
    Inventors: Daoqiang Lu, Chuan Hu, Gilroy J. Vandentop, Shriram Ramanathan, Rajashree Baskaran, Valery M. Dubin
  • Publication number: 20160248006
    Abstract: Reversible phase transitions of exceptional magnitude may be induced in correlated metal oxides by altering their chemical compositions through reversible introduction of dopant ions and electronic carriers into the correlated metal oxides. One or more catalyst electrodes may be deposited onto a surface of a film of a correlated metal oxide such as a perovskite or a transition metal oxide. Dopant ions and electronic carriers may be electrochemically introduced into the catalyst-deposited correlated metal oxide, for example by annealing the catalyst-deposited film of correlated metal oxide in a chamber containing the dopant molecules. In this way, a reversible phase transition of about five to eight orders of magnitude may be induced.
    Type: Application
    Filed: October 31, 2014
    Publication date: August 25, 2016
    Applicant: President and Fellows of Harvard College
    Inventors: Jian Shi, You Zhou, Shriram Ramanathan
  • Patent number: 9343206
    Abstract: A tunable resistance system includes a layer of a first functional material deposited on a component of the system. The first functional material undergoes a phase transition at a first critical voltage. An insulating layer is deposited upon the layer of first functional material. A layer of a second functional material deposited on the insulating layer. The second functional material undergoes a phase transition at a second critical voltage. The insulating layer is configured to induce a stress on the layer so as to change the first critical voltage. In this way, the resistance of the system is tunable, allowing the system to undergo multi-stage electrical switching of resistive states.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: May 17, 2016
    Assignee: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: You Zhou, Zheng Yang, Shriram Ramanathan
  • Publication number: 20150340607
    Abstract: Phase transition devices may include a functional layer made of functional material that can undergo a change in conductance in response to an external stimulus such as an electric or magnetic or optical field, or heat. The functional material transitions between a conducting state and a non-conducting state, upon application of the external stimulus. A capacitive device may include a functional layer between a top electrode and a bottom electrode, and a dielectric layer between the functional layer and the top electrode. A three terminal phase transition switch may include a functional layer, for example a conductive oxide channel, deposited between a source and a drain, and a gate dielectric layer and a gate electrode deposited on the functional layer. An array of phase transition switches and/or capacitive devices may be formed on a substrate, which may be made of inexpensive flexible material.
    Type: Application
    Filed: August 3, 2015
    Publication date: November 26, 2015
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Shriram RAMANATHAN, Dmitry RUZMETOV, Venkatesh NARAYANAMURTI, Changhyun KO
  • Publication number: 20150188176
    Abstract: A solid oxide fuel cell has a reinforced membrane-electrode assembly. The solid oxide fuel cell includes a first electrode layer, a second electrode layer, and an electrolyte membrane disposed between the first and second electrode layers. The solid oxide fuel cell further includes a gas-permeable structure adjacent to one or both of the electrode layers, for mechanical stabilization.
    Type: Application
    Filed: March 11, 2015
    Publication date: July 2, 2015
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Shriram RAMANATHAN, Alexander C. JOHNSON
  • Publication number: 20140375417
    Abstract: A tunable resistance system includes a layer of a first functional material deposited on a component of the system. The first functional material undergoes a phase transition at a first critical voltage. An insulating layer is deposited upon the layer of first functional material. A layer of a second functional material deposited on the insulating layer. The second functional material undergoes a phase transition at a second critical voltage. The insulating layer is configured to induce a stress on the layer so as to change the first critical voltage. In this way, the resistance of the system is tunable, allowing the system to undergo multi-stage electrical switching of resistive states.
    Type: Application
    Filed: February 6, 2013
    Publication date: December 25, 2014
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: You Zhou, Zheng Yang, Shriram Ramanathan
  • Patent number: 8864957
    Abstract: Thin films of vanadium oxide having exceptionally high metal-insulator transition properties are synthesized by RF sputtering. An Al2O3 substrate is placed in a sputtering chamber and heated to a temperature up to about 550 degrees Celsius. Ar and O2 gases are introduced into the sputtering chamber at the flow values of about 92.2 sccm and about 7.8 sccm respectively. A voltage is applied to create a plasma in the chamber. A sputtering gun with vanadium target material is ignited and kept at a power of about 250 W. The phase transition parameters of vanadium dioxide thin films, synthesized by RF sputtering, are modulated by exposing the vanadium dioxide thin film to UV (ultraviolet) radiation so as to induce a change in oxygen incorporation of the vanadium dioxide thin film.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: October 21, 2014
    Assignee: President and Fellows of Harvard College
    Inventors: Shriram Ramanathan, Dmitry Ruzmetov, Venkatesh Narayanamurti, Changhyun Ko
  • Patent number: 8815466
    Abstract: In various aspects, provided are solid oxide fuel cells with an operational temperature of less than about 500° C. that can provide, in various embodiments, a power density of greater than about 0.1 W/cm2 and/or have an ionic conductivity of greater than about 0.00001 ohm?1 cm?1. In various embodiments, provided are solid oxide fuel cells comprising a solid oxide electrolyte layer that is both an electronic and ionic conductor. In various aspects, provided are methods of making solid oxide fuel cells. In various aspects, provided are solid oxide materials comprising a polycrystalline ceramic layer less than about 100 nm thick having a ionic conductivity of greater than about 0.00001 ohm?1 cm?1 at a temperature less than about 500° C.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: August 26, 2014
    Assignee: President and Fellows of Harvard College
    Inventors: Shriram Ramanathan, Alexander C. Johnson
  • Publication number: 20140051008
    Abstract: A method of forming a catalyst material includes coating agglomerates of catalyst support particles with an ionomer material. After coating the agglomerates of catalyst support particles, a catalyst metal precursor is deposited by chemical infiltration onto peripheral surfaces of the agglomerates of catalyst support particles. The catalyst metal precursor is then chemically reduced to form catalyst metal on the peripheral surfaces of the agglomerates of catalyst support particles.
    Type: Application
    Filed: April 25, 2011
    Publication date: February 20, 2014
    Inventors: Shriram Ramanathan, Laura Roen Stolar
  • Publication number: 20140008281
    Abstract: Embodiments of the invention relate to device, method, and system for separation and/or detection of biological cells and biomolecules using micro-channels, magnetic interactions, and magnetic tunnel junctions. The micro-channels can be integrated into a microfluidic device that may be part of an integrated circuit. Magnetic interactions used for the separation are created, in part, by magnetic stripes associated with the micro-channels. Detection of biological cells and biomolecules is effectuated by a magnetic tunnel junction sensor that comprises two ferromagnetic layers separated by a thin insulating layer. The magnetic tunnel junction sensor can be integrated into a silicon based device, such a microfluidic device, an integrated circuit, or a microarray to achieve rapid and specific separation and/or detection of biomolecules and cells.
    Type: Application
    Filed: July 31, 2013
    Publication date: January 9, 2014
    Applicant: Intel Corporation
    Inventors: Shriram RAMANATHAN, Chang-Min PARK
  • Publication number: 20130344659
    Abstract: A method of fabricating a microelectronic package having a direct contact heat spreader, a package formed according to the method, a die-heat spreader combination formed according to the method, and a system incorporating the package. The method comprises metallizing a backside of a microelectronic die to form a heat spreader body directly contacting and fixed to the backside of the die thus yielding a die-heat spreader combination. The package includes the die-heat spreader combination and a substrate bonded to the die.
    Type: Application
    Filed: August 22, 2013
    Publication date: December 26, 2013
    Inventors: Daoqiang Lu, Chuan Hu, Gilroy J. Vandentop, Shriram Ramanathan, Rajashree Baskaran, Valery M. Dubin
  • Publication number: 20130256122
    Abstract: A system includes an electrochemically functional membrane, and a support structure constructed and arranged so as to support the membrane while leaving within the membrane a chemically active area having an area utilization of at least about 50%. In some embodiments, the support structure may include a plurality of grids that are sized and shaped so that the contact area between the grids and the membrane is reduced to less than about 40%. In some embodiments, the support structure may include aerogels, for example PVA-reinforced CNT aerogels having a conductivity that is increased by pyrolysis. The system may be a gas separation system; a gas production system; a gas purification system; or an energy generation system such as an SOFC.
    Type: Application
    Filed: August 31, 2011
    Publication date: October 3, 2013
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Shriram Ramanathan, Daniel V. Harburg, Masaru Tsuchiya, Alexander C. Johnson