Patents by Inventor Stefan-Dan Costea

Stefan-Dan Costea 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: 10585058
    Abstract: An illustrative humidity sensor may include a substrate having a source and a drain, wherein the drain is laterally spaced from the source. A gate stack is provided in the space between the source and the drain to form a transistor. The gate stack may include a gate insulator situated on the substrate to form a gate insulator/substrate interface. The gate stack may further include a barrier layer above the gate insulator. The barrier layer may be configured to act as a barrier to mobile charge, humidity and/or other contaminates, and may help prevent such contaminates from reaching the gate insulator/substrate interface. The gate stack may further include a humidity sensing layer above the barrier layer. The humidity sensing layer, when exposed to humidity, may modulate the conduction channel in the substrate under the gate insulator and between the source and the drain. In some cases, the humidity level may be determined by monitoring the current flowing between the source and drain.
    Type: Grant
    Filed: May 12, 2017
    Date of Patent: March 10, 2020
    Assignee: Honeywell International Inc.
    Inventors: Cornel Cobianu, Alisa Stratulat, Bogdan Serban, Octavian Buiu, Cazimir Gabriel Bostan, Mihai Brezeanu, Stefan Dan Costea, Richard Davis
  • Publication number: 20170328855
    Abstract: An illustrative humidity sensor may include a substrate having a source and a drain, wherein the drain is laterally spaced from the source. A gate stack is provided in the space between the source and the drain to form a transistor. The gate stack may include a gate insulator situated on the substrate to form a gate insulator/substrate interface. The gate stack may further include a barrier layer above the gate insulator. The barrier layer may be configured to act as a barrier to mobile charge, humidity and/or other contaminates, and may help prevent such contaminates from reaching the gate insulator/substrate interface. The gate stack may further include a humidity sensing layer above the barrier layer. The humidity sensing layer, when exposed to humidity, may modulate the conduction channel in the substrate under the gate insulator and between the source and the drain. In some cases, the humidity level may be determined by monitoring the current flowing between the source and drain.
    Type: Application
    Filed: May 12, 2017
    Publication date: November 16, 2017
    Inventors: Cornel Cobianu, Alisa Stratulat, Bogdan Serban, Octavian Buiu, Cazimir Gabriel Bostan, Mihai Brezeanu, Stefan Dan Costea, Richard Davis
  • Patent number: 9557229
    Abstract: A dynamic strain sensor includes a strain sensitive transistor and a light emitting diode coupled to the strain sensitive transistor. The dynamic strain sensor can include a piezoelectric layer incorporated into the structure of the strain sensitive transistor. The dynamic strain sensor can sense dynamic strain and can measure and monitor the dynamic strain wirelessly.
    Type: Grant
    Filed: December 9, 2014
    Date of Patent: January 31, 2017
    Assignee: Honeywell Romania s.r.l.
    Inventors: Viorel Georgel Dumitru, Stefan Dan Costea, Ion Georgescu, Mihai Brezeanu
  • Patent number: 9448655
    Abstract: The present disclosure relates to a touch sensor and touch sensitive display having a plurality of first and second conductive lines arranged substantially orthogonally with a sensing material to sense a change in capacitance between them. The first and second conductive lines and the sensing material defining an array of sensitive transistors.
    Type: Grant
    Filed: July 16, 2014
    Date of Patent: September 20, 2016
    Assignee: Honeywell International Inc.
    Inventors: Viorel Georgel Dumitru, Stefan Dan Costea, Ion Georgescu, Mihai Brezeanu, Bogdan-Catalin Serban
  • Publication number: 20150177078
    Abstract: A dynamic strain sensor includes a strain sensitive transistor and a light emitting diode coupled to the strain sensitive transistor. The dynamic strain sensor can include a piezoelectric layer incorporated into the structure of the strain sensitive transistor. The dynamic strain sensor can sense dynamic strain and can measure and monitor the dynamic strain wirelessly.
    Type: Application
    Filed: December 9, 2014
    Publication date: June 25, 2015
    Inventors: Viorel Georgel DUMITRU, Stefan Dan COSTEA, Ion GEORGESCU, Mihai BREZEANU
  • Publication number: 20150022491
    Abstract: The present disclosure relates to a touch sensor and touch sensitive display having a plurality of first and second conductive lines arranged substantially orthogonally with a sensing material to sense a change in capacitance between them. The first and second conductive lines and the sensing material defining an array of sensitive transistors.
    Type: Application
    Filed: July 16, 2014
    Publication date: January 22, 2015
    Inventors: Viorel Georgel Dumitru, Stefan Dan Costea, Ion Georgescu, Mihai Brezeanu, Bogdan-Catalin Serban
  • Patent number: 8546817
    Abstract: An example sensor that includes a first Schottky diode, a second Schottky diode and an integrated circuit. The sensor further includes a voltage generator that generates a first voltage across the first Schottky diode and a second voltage across the second Schottky diode. When the first Schottky diode and the second Schottky diode are subjected to different strain, the integrated circuit measures the values of the currents flowing through the first Schottky diode and the second Schottky diode to determine the strain on an element where the first Schottky diode and the second Schottky diode are attached.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: October 1, 2013
    Assignee: Honeywell International Inc.
    Inventors: Viorel Georgel Dumitru, Mihai Brezeanu, Stefan Dan Costea, Ion Georgescu, Viorel Avramescu, Bogdan Catalin Serban
  • Patent number: 8519449
    Abstract: A piezoelectric strain sensor and method thereof for detecting strain, vibration, and/or pressure. The sensor incorporates a sequence of piezoelectric and semiconductor layers in a thin-film transistor structure. The thin-film transistor structure can be configured on a flexible substrate via a low-cost fabrication technique. The piezoelectric layer generates an electric charge resulting in a modulation of a transistor current, which is a measure of external strain. The sensor can be formed as a single gate field-effect piezoelectric sensor and a dual gate field-effect piezoelectric sensor. The semiconductor layer can be configured from a nanowire array resulting in a metal-piezoelectric-nanowire field effect transistor. The single and dual gate field-effect piezoelectric sensor offer increased sensitivity and device control due to the presence of the piezoelectric layer in the transistor structure and low cost manufacturability on large area flexible substrates.
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: August 27, 2013
    Assignee: Honeywell International Inc.
    Inventors: Viorel-Georgel Dumitru, Cornel Cobianu, Stefan-Dan Costea, Bogdan-Catalin Serban
  • Publication number: 20130171027
    Abstract: A fluorescence quenching oxygen sensor (100) comprises a support (102) having coated thereon; a compound having hard or soft acid groups (104); and one or more pyrene compounds (106) represented by Y—R-Pyrene??(I) attached to the compound having hard or soft basic groups; wherein Y is a hard or soft basic group and R is an aliphatic linking group having 1 to 19 carbon atoms. The sensor can be used to prepare a fluorescence quenching oxygen detector.
    Type: Application
    Filed: December 28, 2012
    Publication date: July 4, 2013
    Applicant: Honeywell International Inc.
    Inventors: Bogdan Catalin Serban, Mihai N. Mihaila, Octavian Buiu, Stefan Dan Costea
  • Patent number: 8317998
    Abstract: A method of operating an electrochemical gas sensor includes: a) exposing, for a first predetermined duration, the electrochemical gas sensor to an atmosphere containing a target gas while the gas reaction capability of the electrode assembly is substantially reduced from a working level, such that target gas is collected within the housing; b) increasing the gas reaction capability of the electrode assembly to a level at which it consumes collected target gas and thereby outputs a signal to the sensing circuit, including an initial transient decay signal; c) monitoring the transient decay signal; and d) analysing the rate of decay of the transient decay signal to determine whether the performance of at least one component of the electrochemical gas sensor is within acceptable limits. An apparatus for operating an electrochemical gas sensor, adapted for connection to an electrochemical gas sensor via a sensing circuit for control thereof, can carry out the disclosed method(s).
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: November 27, 2012
    Assignee: Life Safety Distribution AG
    Inventors: Keith Francis Edwin Pratt, John Chapples, Martin Jones, Stefan Dan Costea, Mihai Gologanu
  • Patent number: 8299355
    Abstract: A solar cell including a quantum dot and an electron conductor, with a bifunctional ligand disposed between the quantum dot and the electron conductor. The bifunctional ligand molecule may include an electron conductor anchor that bonds to the electron conductor and a first quantum dot anchor that bonds to the quantum dot. A hole conductor such as a conductive polymer may include a second quantum dot anchor. In some instances, the first quantum dot may include selenium.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: October 30, 2012
    Assignee: Honeywell International Inc.
    Inventors: Bogdan Serban, Mihai N. Mihaila, Viorel Georgel Dumitru, Cazimir Bostan, Stefan Dan Costea
  • Patent number: 8283561
    Abstract: A solar cell including a quantum dot and an electron conductor, and a bifunctional ligand disposed between the quantum dot and the electron conductor. The bifunctional ligand molecule may include an electron conductor anchor that bonds to the electron conductor and a first quantum dot anchor that bonds to the quantum dot. A hole conductor such as a conductive polymer may include a second quantum dot anchor.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: October 9, 2012
    Assignee: Honeywell International Inc.
    Inventors: Bogdan Serban, Mihai N. Mihaila, Stefan Dan Costea, Viorel Georgel Dumitru
  • Publication number: 20120161147
    Abstract: An example sensor that includes a first Schottky diode, a second Schottky diode and an integrated circuit. The sensor further includes a voltage generator that generates a first voltage across the first Schottky diode and a second voltage across the second Schottky diode. When the first Schottky diode and the second Schottky diode are subjected to different strain, the integrated circuit measures the values of the currents flowing through the first Schottky diode and the second Schottky diode to determine the strain on an element where the first Schottky diode and the second Schottky diode are attached.
    Type: Application
    Filed: November 30, 2011
    Publication date: June 28, 2012
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: Viorel Georgel DUMITRU, Mihai Brezeanu, Stefan Dan Costea, Ion Georgescu, Viorel Avramescu, Bogdan-Catalin Serban
  • Publication number: 20110049579
    Abstract: A piezoelectric strain sensor and method thereof for detecting strain, vibration, and/or pressure. The sensor incorporates a sequence of piezoelectric and semiconductor layers in a thin-film transistor structure. The thin-film transistor structure can be configured on a flexible substrate via a low-cost fabrication technique. The piezoelectric layer generates an electric charge resulting in a modulation of a transistor current, which is a measure of external strain. The sensor can be formed as a single gate field-effect piezoelectric sensor and a dual gate field-effect piezoelectric sensor. The semiconductor layer can be configured from a nanowire array resulting in a metal-piezoelectric-nanowire field effect transistor. The single and dual gate field-effect piezoelectric sensor offer increased sensitivity and device control due to the presence of the piezoelectric layer in the transistor structure and low cost manufacturability on large area flexible substrates.
    Type: Application
    Filed: July 23, 2010
    Publication date: March 3, 2011
    Inventors: Viorel-Georgel Dumitru, Cornel Cobianu, Stefan-Dan Costea, Bogdan-Catalin Serban
  • Patent number: 7891252
    Abstract: A method includes forming multiple trenches in a first wafer, forming a sensor structure on a first surface of a second wafer, and bonding the first wafer and the second wafer. The method also includes etching a second surface of the second wafer to form a sensor diaphragm in the second wafer. The method further includes removing a portion of the first wafer by cutting the first wafer in multiple areas of the first wafer associated with the trenches. A sensor includes a substrate and a surface acoustic wave (SAW) resonator on a first surface of the substrate. The sensor also includes a bonding pad electrically coupled to the SAW resonator and a notch formed in a second surface of the substrate. The sensor further includes a cover separated from the first surface of the substrate by a spacer. The SAW resonator is located between the cover and the substrate.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: February 22, 2011
    Assignee: Honeywell International Inc.
    Inventors: Cornel Cobianu, Viorel Avramescu, Ion Georgescu, Stefan-Dan Costea
  • Patent number: 7867552
    Abstract: Methods can be adapted for design of a sensitive monolayer for detection of hydrogen sulphide at room temperature with SAW/BAW devices. The sensitive monolayer can be synthesized based on chemical compounds, which belongs to a class of thiacalix[n]arenas, mercapto halides, mercapto alcohols and chloromethylated thiacalix[n]arenas. The sensitive monolayer can be directly immobilized or anchored at the surface of a piezoelectric quartz substrate in a covalently bonded manner by means of direct printing process. The piezoelectric quartz substrate can be activated in basic medium or in acid medium before the immobilization of the sensitive monolayer in order to increase the population of OH groups. Thus, the synthesized sensitive monolayer exhibits a high site density, fast response and long-term stability for H2S sensing.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: January 11, 2011
    Assignee: Honeywell International Inc.
    Inventors: Bogdan-Catalin Serban, Viorel-Georgel Dumitru, Cornel P. Cobianu, Stefan-Dan Costea, Nicolae Varachiu, Stefan I. Voicu
  • Publication number: 20100252455
    Abstract: A method of operating an electrochemical gas sensor includes: a) exposing, for a first predetermined duration, the electrochemical gas sensor to an atmosphere containing a target gas whilst the gas reaction capability of the electrode assembly is substantially reduced from a working level, such that target gas is collected within the housing; b) increasing the gas reaction capability of the electrode assembly to a level at which it consumes collected target gas and thereby outputs a signal to the sensing circuit, including an initial transient decay signal; c) monitoring the transient decay signal; and d) analysing the rate of decay of the transient decay signal to determine whether the performance of at least one component of the electrochemical gas sensor is within acceptable limits. An apparatus for operating an electrochemical gas sensor, adapted for connection to an electrochemical gas sensor via a sensing circuit for control thereof, can carry out the disclosed method(s).
    Type: Application
    Filed: April 5, 2010
    Publication date: October 7, 2010
    Inventors: Keith Francis Edwin Pratt, John Chapples, Martin Jones, Stefan Dan Costea, Mihai Gologanu
  • Publication number: 20100193026
    Abstract: A solar cell is disclosed that may include a quantum dot, an electron conductor, and a bifunctional ligand disposed between the quantum dot and the electron conductor. The bifunctional ligand may include a first anchor group that bonds to the quantum dot and a second anchor group that bonds to the electron conductor. The solar cell may include a hole conductor that is configured to reduce the quantum dot once the quantum dot absorbs a photon and ejects an electron through the bifunctional ligand and into the electron conductor. The hole conductor may be a p-type polymer.
    Type: Application
    Filed: January 28, 2010
    Publication date: August 5, 2010
    Applicant: Honeywell International Inc.
    Inventors: Bogdan Serban, Mihai N. Mihaila, Stefan Dan Costea, Octavian Buiu
  • Publication number: 20100193025
    Abstract: A solar cell is disclosed that may include a quantum dot, an electron conductor, and a bifunctional ligand disposed between the quantum dot and the electron conductor. The bifunctional ligand may include a first anchor group that bonds to the quantum dot and a second anchor group that bonds to the electron conductor. The solar cell may include a hole conductor that is configured to reduce the quantum dot once the quantum dot absorbs a photon and ejects an electron through the bifunctional ligand and into the electron conductor. The hole conductor may be a p-type polymer.
    Type: Application
    Filed: January 28, 2010
    Publication date: August 5, 2010
    Applicant: Honeywell International Inc.
    Inventors: Bogdan Serban, Mihai N. Mihaila, Stefan Dan Costea, Mircea Bercu
  • Publication number: 20100141087
    Abstract: A SAW based sensor apparatus utilizing semi-synchronous SAW resonator having a single resonance at Bragg frequency with very high quality factor is disclosed. The semi-synchronous SAW resonator includes at least one inter-digital transducer, which generates and receives surface acoustic wave and a number of grating reflectors, which reflect the surface acoustic wave and generate a standing wave between the reflectors, The interdigital transducer and the grating reflectors can be fabricated on a substrate (e.g., quartz) by photolithographic process. The resonance condition is independent of transducer directivity and reflection coefficient per finger. Such a SAW based sensor apparatus having three semi-synchronous SAW resonators can be utilized for measuring pressure and temperature for a wireless tire-pressure monitoring system.
    Type: Application
    Filed: December 10, 2008
    Publication date: June 10, 2010
    Inventors: Cazimir Bostan, Stefan Dan Costea, Viorel Avramescu, Cornel Cobianu