Patents by Inventor Arunava Majumdar
Arunava Majumdar 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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Patent number: 11926783Abstract: A method of electrochemical redox refrigeration includes inducing a flow of an electrochemical refrigerant that is in contact with a first electrode to a second electrode; applying an electrical potential difference between the first electrode and the second electrode, wherein the electrochemical refrigerant is oxidized at one of the first electrode and second electrode and reduced at another of the first electrode and second electrode; wherein the first electrode is at least partially thermally isolated from Joule heating in the electrochemical refrigerant and from activation losses in the second electrode by an action of the flow of the electrochemical refrigerant.Type: GrantFiled: April 13, 2020Date of Patent: March 12, 2024Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Arunava Majumdar, Ian S. McKay
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Publication number: 20220165905Abstract: In certain examples, methods and photo-responsive structures are directed to devices involving a diamond-based photoconductive switch having a doped diamond-grown material in the switch. The doped diamond-grown material may be formed from different gases combined on a diamond seed, such that as grown, the diamond-based material manifests a controlled dopant concentration level of a polarity type and over a depth of optical absorption sufficient to ionize the dopants in response to an optical signal.Type: ApplicationFiled: November 19, 2021Publication date: May 26, 2022Inventors: Srabanti Chowdhury, Kelly Woo, Arunava Majumdar
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Publication number: 20210374484Abstract: Pattern recognition by receiving a set multi-variable data records, each record including a plurality of variables, representing at least two of the plurality of variables as geometric shapes, defining a boundary enclosing the geometric shapes, configuring at least one geometric shape to move within the boundary, capturing a location of each of the geometric shapes within the boundary as a system state, one or more times, combining one or more system states as a system signature, providing a model trained to recognize patterns in system signatures, and recognizing a pattern in the system signature.Type: ApplicationFiled: May 29, 2020Publication date: December 2, 2021Inventors: David Bacarella, Arunava Majumdar, Stephan Joseph Roorda, Sumit Patel
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Patent number: 11101102Abstract: A method for chemical identification of a sample having nanostructures includes the steps of irradiating the surface at wavelengths for each of a first and a second of the nanostructures that are uniquely absorbed by each of the first nanostructure and the second nanostructure such that each is excited to modulate at a first or a second nanostructure frequency, respectively. The method continues with the steps of irradiating the surface with electron beams incident on each of the first and second nanostructure, wherein at least one of secondary electrons, backscattered electrons and transmitted electrons are modulated at the frequency corresponding to each of the first and second nanostructure frequencies. A chemical map of the sample at an atomic scale is then created. A microscope is provided to carry out the method.Type: GrantFiled: August 25, 2020Date of Patent: August 24, 2021Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Arunava Majumdar, Ze Zhang, Joel Martis
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Patent number: 11024474Abstract: Methods, systems, and apparatus for circuit breakers with integrated safety, control, monitoring, and protection features. In one aspect, a circuit breaker includes, an input and an output, a switch coupled between the input and the output, a sensor configured to measure the current flowing from the input to the output, and a control system coupled to the sensor and the switch, wherein the control system is configured to perform operations including comparing a rate of change of the current measured by the sensor to a threshold rate of change of current, determining that the rate of change of the current measured by the sensor exceeds the threshold rate of change of current for at least a predetermined period of time, and as a consequence of determining that the rate of change of current exceeds the threshold rate of change, opening the switch, thereby disconnecting the input from the output.Type: GrantFiled: January 14, 2019Date of Patent: June 1, 2021Assignee: Google LLCInventors: Jyoti Sastry, Anand Ramesh, Gregory E. Leyh, Ronald Scott Collyer, Arunava Majumdar, Ankit Somani
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Patent number: 10995005Abstract: A two-step thermochemical gas reduction process based on poly-cation oxides includes repeatedly cycling a thermal reduction step and a gas reduction step. In the thermal reduction the poly-cation oxide is heated to produce a reduced poly-cation oxide and oxygen. In the gas reduction step, the reduced poly-cation oxide is reacted with a gas to reduce the gas, while reoxidizing the poly-cation oxide. The poly-cation oxide has at least two distinct crystal structures at two distinct temperatures and is capable of undergoing a reversible phase transformation between the two distinct crystal structures. For example, the poly-cation oxide may be an entropy tuned mixed metal oxide, such as an entropy stabilized mixed metal oxide, where the entropy-tuning is achieved via change in crystal structure of one of more of the compounds involved. The gas reduction process may be used for water splitting, CO2 splitting, NOx reduction, and other gas reduction processes.Type: GrantFiled: October 28, 2017Date of Patent: May 4, 2021Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Nadia L. Ahlborg, William C. Chueh, Hyungyu Jin, Arunava Majumdar, Shang Zhai, Jimmy A. Rojas Herrera
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Publication number: 20210066030Abstract: A method for chemical identification of a sample having nanostructures includes the steps of irradiating the surface at wavelengths for each of a first and a second of the nanostructures that are uniquely absorbed by each of the first nanostructure and the second nanostructure such that each is excited to modulate at a first or a second nanostructure frequency, respectively. The method continues with the steps of irradiating the surface with electron beams incident on each of the first and second nanostructure, wherein at least one of secondary electrons, backscattered electrons and transmitted electrons are modulated at the frequency corresponding to each of the first and second nanostructure frequencies. A chemical map of the sample at an atomic scale is then created. A microscope is provided to carry out the method.Type: ApplicationFiled: August 25, 2020Publication date: March 4, 2021Inventors: Arunava MAJUMDAR, Ze ZHANG, Joel MARTIS
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Publication number: 20200325379Abstract: A method of electrochemical redox refrigeration includes inducing a flow of an electrochemical refrigerant that is in contact with a first electrode to a second electrode; applying an electrical potential difference between the first electrode and the second electrode, wherein the electrochemical refrigerant is oxidized at one of the first electrode and second electrode and reduced at another of the first electrode and second electrode; wherein the first electrode is at least partially thermally isolated from Joule heating in the electrochemical refrigerant and from activation losses in the second electrode by an action of the flow of the electrochemical refrigerant.Type: ApplicationFiled: April 13, 2020Publication date: October 15, 2020Inventors: Arunava Majumdar, Ian S. McKay
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Patent number: 10615111Abstract: An interposer for vertically separating device die is disclosed. The interposer includes a compliant layer comprising a plurality of thermally conductive plugs that are physically disconnected within the plane of the compliant layer, where the space between the plugs is filled with a compliant medium. In some embodiments, at least one of the top and bottom surfaces of the compliant layer is coated with a thin layer of electrically insulating material.Type: GrantFiled: November 2, 2015Date of Patent: April 7, 2020Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Arunava Majumdar, Seid H. Sadat, Dusan Coso
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Publication number: 20190296382Abstract: A direct thermoelectrochemical heat-to-electricity converter includes two electrochemical cells at hot and cold temperatures, each having a gas-impermeable, electron-blocking membrane capable of transporting an ion I, and a pair of electrodes on opposite sides of the membrane. Two closed-circuit chambers A and B each includes a working fluid, a pump, and a counter-flow heat exchanger. The chambers are connected to opposite sides of the electrochemical cells and carry their respective working fluids between the two cells. The working fluids are each capable of undergoing a reversible redox half-reaction of the general form R?O+I+e?, where R is a reduced form of an active species in a working fluid and O is the oxidized forms of the active species. One of the first pair of electrodes is electrically connected to one the second pair of electrodes via an electrical load to produce electricity.Type: ApplicationFiled: June 5, 2019Publication date: September 26, 2019Inventors: William C. Chueh, Andrey D. Poletayev, Ian S. McKay, Arunava Majumdar
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Patent number: 10224155Abstract: Methods, systems, and apparatus for circuit breakers with integrated safety, control, monitoring, and protection features. In one aspect, a circuit breaker includes, an input and an output, a switch coupled between the input and the output, a sensor configured to measure the current flowing from the input to the output, and a control system coupled to the sensor and the switch, wherein the control system is configured to perform operations including comparing a rate of change of the current measured by the sensor to a threshold rate of change of current, determining that the rate of change of the current measured by the sensor exceeds the threshold rate of change of current for at least a predetermined period of time, and as a consequence of determining that the rate of change of current exceeds the threshold rate of change, opening the switch, thereby disconnecting the input from the output.Type: GrantFiled: April 14, 2017Date of Patent: March 5, 2019Assignee: Google LLCInventors: Jyoti Sastry, Anand Ramesh, Gregory E. Leyh, Ronald Scott Collyer, Arunava Majumdar, Ankit Somani
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Patent number: 9966761Abstract: In general, one innovative aspect of the subject matter described in this specification can be embodied in a load control system configured to perform load control operations comprising: measuring a voltage on an electrical grid at a plurality of times; determining, for each time of the plurality of times, a difference between a specified normal voltage and the respective measured voltage at that time; summing the differences between the specified normal voltage and the measured voltages to determine a curtailment level; determining whether the curtailment level exceeds a first threshold curtailment level; and in response to determining that the curtailment level exceeds the first threshold curtailment level, adjusting an amount of power drawn by a load.Type: GrantFiled: May 23, 2014Date of Patent: May 8, 2018Assignee: Google LLCInventors: Sangsun Kim, Anand Ramesh, Ronald Scott Collyer, Jyoti Sastry, Arunava Majumdar
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Publication number: 20180118576Abstract: A two-step thermochemical gas reduction process based on poly-cation oxides includes repeatedly cycling a thermal reduction step and a gas reduction step. In the thermal reduction the poly-cation oxide is heated to produce a reduced poly-cation oxide and oxygen. In the gas reduction step, the reduced poly-cation oxide is reacted with a gas to reduce the gas, while reoxidizing the poly-cation oxide. The poly-cation oxide has at least two distinct crystal structures at two distinct temperatures and is capable of undergoing a reversible phase transformation between the two distinct crystal structures. For example, the poly-cation oxide may be an entropy tuned mixed metal oxide, such as an entropy stabilized mixed metal oxide, where the entropy-tuning is achieved via change in crystal structure of one of more of the compounds involved. The gas reduction process may be used for water splitting, CO2 splitting, NOx reduction, and other gas reduction processes.Type: ApplicationFiled: October 28, 2017Publication date: May 3, 2018Inventors: Nadia L. Ahlborg, William C. Chueh, Hyungyu Jin, Arunava Majumdar, Shang Zhai, Jimmy A. Rojas Herrera
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Publication number: 20170288253Abstract: A direct thermoelectrochemical heat-to-electricity converter includes two electrochemical cells at hot and cold temperatures, each having a gas-impermeable, electron-blocking membrane capable of transporting an ion I, and a pair of electrodes on opposite sides of the membrane. Two closed-circuit chambers A and B each includes a working fluid, a pump, and a counter-flow heat exchanger. The chambers are connected to opposite sides of the electrochemical cells and carry their respective working fluids between the two cells. The working fluids are each capable of undergoing a reversible redox half-reaction of the general form R?O+I+e?, where R is a reduced form of an active species in a working fluid and O is the oxidized forms of the active species. One of the first pair of electrodes is electrically connected to one the second pair of electrodes via an electrical load to produce electricity.Type: ApplicationFiled: March 29, 2017Publication date: October 5, 2017Inventors: William C. Chueh, Andrey D. Poletayev, Ian S. McKay, Arunava Majumdar
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Patent number: 9659721Abstract: Methods, systems, and apparatus for circuit breakers with integrated safety, control, monitoring, and protection features. In one aspect, a circuit breaker includes, an input and an output, a switch coupled between the input and the output, a sensor configured to measure the current flowing from the input to the output, and a control system coupled to the sensor and the switch, wherein the control system is configured to perform operations including comparing a rate of change of the current measured by the sensor to a threshold rate of change of current, determining that the rate of change of the current measured by the sensor exceeds the threshold rate of change of current for at least a predetermined period of time, and as a consequence of determining that the rate of change of current exceeds the threshold rate of change, opening the switch, thereby disconnecting the input from the output.Type: GrantFiled: May 6, 2015Date of Patent: May 23, 2017Assignee: Google Inc.Inventors: Jyoti Sastry, Anand Ramesh, Gregory E. Leyh, Ronald Scott Collyer, Arunava Majumdar, Ankit Somani
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Publication number: 20160358247Abstract: In one embodiment, a method for displaying an electronic message with a networked electronically programmable dynamic display (NEPDD) includes executing on a processor the step of receiving at least one bid from one or more display bidders for display space on an NEPDD device to display an electronic message. The method includes the step of notifying one or more NEPDD displayers of the bid. The method includes the step of receiving a bid selection from the one or more NEPDD displayers. The method includes the step of communicating the electronic message along with display instructions to each NEPDD management application of the one or more NEPDD displayers.Type: ApplicationFiled: December 11, 2015Publication date: December 8, 2016Inventor: ARUNAVA MAJUMDAR
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Patent number: 9385065Abstract: Thermal rectifiers using linear nanostructures as core thermal conductors have been fabricated. A high mass density material is added preferentially to one end of the nanostructures to produce an axially non-uniform mass distribution. The resulting nanoscale system conducts heat asymmetrically with greatest heat flow in the direction of decreasing mass density. Thermal rectification has been demonstrated for linear nanostructures that are electrical insulators, such as boron nitride nanotubes, and for nanostructures that are conductive, such as carbon nanotubes.Type: GrantFiled: October 2, 2007Date of Patent: July 5, 2016Assignee: The Regents of the University of CaliforniaInventors: Chih-Wei Chang, Arunava Majumdar, Alexander K. Zettl
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Publication number: 20160126159Abstract: An interposer for vertically separating device die is disclosed. The interposer includes a compliant layer comprising a plurality of thermally conductive plugs that are physically disconnected within the plane of the compliant layer, where the space between the plugs is filled with a compliant medium. In some embodiments, at least one of the top and bottom surfaces of the compliant layer is coated with a thin layer of electrically insulating material.Type: ApplicationFiled: November 2, 2015Publication date: May 5, 2016Inventors: Arunava Majumdar, Seid H. Sadat, Dusan Coso
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Patent number: 9219215Abstract: The invention provides for a nanostructure, or an array of such nanostructures, each comprising a rough surface, and a doped or undoped semiconductor. The nanostructure is an one-dimensional (1-D) nanostructure, such a nanowire, or a two-dimensional (2-D) nanostructure. The nanostructure can be placed between two electrodes and used for thermoelectric power generation or thermoelectric cooling.Type: GrantFiled: March 26, 2014Date of Patent: December 22, 2015Assignee: The Regents of The University of CaliforniaInventors: Peidong Yang, Arunava Majumdar, Allon I. Hochbaum, Renkun Chen, Raul Diaz Delgado
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Patent number: 8957013Abstract: The invention provides for a receptor, capable of binding to a target molecule, linked to a hygroscopic polymer or hydrogel; and the use of this receptor in a device for detecting the target molecule in a gaseous and/or liquid phase. The invention also provides for a method for detecting the presence of a target molecule in the gas phase using the device. In particular, the receptor can be a peptide capable of binding a 2,4,6-trinitrotoluene (TNT) or 2,4,-dinitrotoluene (DNT).Type: GrantFiled: October 13, 2009Date of Patent: February 17, 2015Assignee: The Regents of the University of CaliforniaInventors: Justyn W. Jaworski, Seung-Wuk Lee, Arunava Majumdar, Digvijay A. Raorane