Patents by Inventor Timothy P. Weihs

Timothy P. Weihs 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: 7297626
    Abstract: A Ni2Si-nSiC Ohmic contact is formed by pulsed laser ablation deposition (PLD) of Ni2Si source target deposited on a n-SiC substrate or SiC substrate wafer with SiC epilayer. The Ni2Si Ohmic contact on n-SiC was rapid thermal annealed at 950° C. for 30 s in a N2 ambient. The resultant Ohmic contact is characterized by excellent current-voltage (I-V) characteristics, an abrupt void free contact-SiC interface, retention of the PLD as-deposited contact layer width, smooth surface morphology, and absence of residual carbon within the contact layer or at the interface. The detrimental effects of contact delamination due to stress associated with interfacial voiding; and wire bond failure, non-uniformity of current flow and SiC polytype alteration due to extreme surface roughness; have been eliminated as has electrical instability associated with carbon inclusions at the contact-SiC interface, after prolonged high temperature and power device operation.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: November 20, 2007
    Assignee: United States of America as Represented by the Secretary of the Army
    Inventors: Melanie W. Cole, Timothy P. Weihs
  • Patent number: 7143568
    Abstract: Embodiments of the invention include a method for sealing a container. The method includes, providing at least two components of the container, positioning a crushable material between the at least two components, positioning a reactive multilayer material between the at least two components, deforming the crushable material so as to form a seal between the at least two components, chemically transforming the reactive multilayer material so as to join the at least two components.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: December 5, 2006
    Assignee: Reactive Nano Technologies, Inc.
    Inventors: David Peter Van Heerden, Dale Deger, Timothy P. Weihs, Omar M. Knio
  • Patent number: 7121402
    Abstract: Embodiments of the invention include a method for sealing a container. The method includes, providing at least two components of the container, positioning a crushable material between the at least two components, positioning a reactive multilayer material between the at least two components, deforming the crushable material so as to form a seal between the at least two components, chemically transforming the reactive multilayer material so as to join the at least two components.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: October 17, 2006
    Assignee: Reactive Nano Technologies, Inc
    Inventors: David Peter Van Heerden, Dale Deger, Timothy P. Weihs, Omar M. Knio
  • Patent number: 6991856
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt or soften the joining material, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: January 31, 2006
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Michael Reiss, Omar Knio, Albert Joseph Swiston, Jr., David van Heerden, Todd Hufnagel
  • Patent number: 6991855
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: January 31, 2006
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Omar Knio, Michael Reiss, David van Heerden
  • Patent number: 6863992
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: March 8, 2005
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Omar Knio, Michael Reiss, David van Heerden
  • Publication number: 20040247931
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: December 9, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20040247930
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: December 9, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20040200736
    Abstract: Embodiments of the invention include a method for sealing a container. The method includes, providing at least two components of the container, positioning a crushable material between the at least two components, positioning a reactive multilayer material between the at least two components, deforming the crushable material so as to form a seal between the at least two components, chemically transforming the reactive multilayer material so as to join the at least two components.
    Type: Application
    Filed: April 1, 2004
    Publication date: October 14, 2004
    Inventors: David Peter Van Heerden, Dale Deger, Timothy P. Weihs, Omar M. Knio
  • Publication number: 20040149813
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 5, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20040151939
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 5, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20040149373
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 5, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20040149372
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 5, 2004
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Patent number: 6736942
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Grant
    Filed: May 1, 2001
    Date of Patent: May 18, 2004
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20030164289
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt or soften the joining material, which upon cooling will form a strong bond, joining two or more bulk materials.
    Type: Application
    Filed: September 20, 2002
    Publication date: September 4, 2003
    Applicant: JOHNS HOPKINS UNIVERSITY
    Inventors: Timothy P. Weihs, Michael Reiss, Omar Knio, Albert Joseph Swiston, David van Heerden, Howard Feldmesser, Todd Hufnagel
  • Patent number: 6596101
    Abstract: Preferred embodiments of the invention provide new nanostructured materials and methods for preparing nanostructured materials having increased tensile strength and ductility, increased hardness, and very fine grain sizes making such materials useful for a variety of applications such as rotors, electric generators, magnetic bearings, aerospace and many other structural and nonstructural applications. The preferred nanostructured materials have a tensile yield strength from at least about 1.9 to about 2.3 GPa and a tensile ductility from at least 1%. Preferred embodiments of the invention also provide a method of making a nanostructured material comprising melting a metallic material, solidifying the material, deforming the material, forming a plurality of dislocation cell structures, annealing the deformed material at a temperature from about 0.30 to about 0.70 of its absolute melting temperature, and cooling the material.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: July 22, 2003
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Robert Cammarata, Chia-Ling Chien, Changhe Shang
  • Patent number: 6534194
    Abstract: In accordance with the invention a reactive multilayer foil is fabricated by providing an assembly (stack or multilayer) of reactive layers, inserting the assembly into a jacket, deforming the jacketed assembly to reduce its cross sectional area, flattening the jacketed assembly into a sheet, and then removing the jacket. Advantageously, the assembly is wound into a cylinder before insertion into the jacket, and the jacketed assembly is cooled to a temperature below 100° C. during deforming. The resulting multilayer foil is advantageous as a freestanding reactive foil for use in bonding, ignition or propulsion.
    Type: Grant
    Filed: May 1, 2001
    Date of Patent: March 18, 2003
    Assignee: Johns Hopkins University
    Inventors: Timothy P. Weihs, Michael Reiss
  • Publication number: 20030019096
    Abstract: In accordance with the invention, a magnetic device is made by providing magnetic sheet layers with reactive joining materials that will react to join the layers into a unitary body. The joining materials are reacted, and the device is formed. In a preferred embodiment, the magnetic material is a soft magnetic material such as FeCo alloy, and the reactive joining materials are aluminum and FeCoOx which react to form nonconducting alumina layers between magnetic regions.
    Type: Application
    Filed: June 24, 2002
    Publication date: January 30, 2003
    Inventor: Timothy P. Weihs
  • Publication number: 20020182436
    Abstract: Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt the joining materials, which upon cooling will form a strong bond, joining two or more bulk materials. If no joining material is used, the foil reaction supplies heat directly to at least two bulk materials, melting a portion of each bulk, which upon cooling, form a strong bond.
    Type: Application
    Filed: April 18, 2002
    Publication date: December 5, 2002
    Inventors: Timothy P. Weihs, Todd Hufnagel, Omar Knio, Michael Reiss, David van Heerden, Howard Feldmesser
  • Publication number: 20020069944
    Abstract: Preferred embodiments of the invention provide new nanostructured materials and methods for preparing nanostructured materials having increased tensile strength and ductility, increased hardness, and very fine grain sizes making such materials useful for a variety of applications such as rotors, electric generators, magnetic bearings, aerospace and many other structural and nonstructural applications. The preferred nanostructured materials have a tensile yield strength from at least about 1.9 to about 2.3 GPa and a tensile ductility from at least 1%. Preferred embodiments of the invention also provide a method of making a nanostructured material comprising melting a metallic material, solidifying the material, deforming the material, forming a plurality of dislocation cell structures, annealing the deformed material at a temperature from about 0.30 to about 0.70 of its absolute melting temperature, and cooling the material.
    Type: Application
    Filed: October 3, 2001
    Publication date: June 13, 2002
    Inventors: Timothy P. Weihs, Robert Cammarata, Chia-Ling Chien, Changhe Shang