Patents by Inventor Madan Dubey
Madan Dubey 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: 10541340Abstract: A method for controlling any of a responsivity, response time, and trap characteristics of a two-dimensional (2D) material on a self-assembled monolayers (SAMs) device, the method including modifying a surface of an oxide substrate, in an atomic scale, to create the 2D material, wherein the modifying the surface includes modifying a level of impurities trapped in the surface and a doping level of the surface, and forming charge carrier traps at the surface, wherein a capture rate and an emission rate of the charge carrier is influenced by an exposure to a light signal, and wherein the exposure to the light signal further changes the doping level of the surface.Type: GrantFiled: July 24, 2017Date of Patent: January 21, 2020Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Sina Najmaei, Madan Dubey
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Publication number: 20190027623Abstract: A method for controlling any of a responsivity, response time, and trap characteristics of a two-dimensional (2D) material on a self-assembled monolayers (SAMs) device, the method including modifying a surface of an oxide substrate, in an atomic scale, to create the 2D material, wherein the modifying the surface includes modifying a level of impurities trapped in the surface and a doping level of the surface, and forming charge carrier traps at the surface, wherein a capture rate and an emission rate of the charge carrier is influenced by an exposure to a light signal, and wherein the exposure to the light signal further changes the doping level of the surface.Type: ApplicationFiled: July 24, 2017Publication date: January 24, 2019Inventors: SINA NAJMAEI, MADAN DUBEY
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Patent number: 9573856Abstract: A micro-explosive material is provided. The micro-explosive material can include a carbon nanotube and a solid oxidizer attached to the carbon nanotube. The carbon nanotube with the solid oxidizer attached thereto is operable to burn per an exothermic chemical reaction between the carbon nanotube and the solid oxidizer such that a controlled burn and/or an explosive burn is provided. The micro-explosive material can be used as a heat generator, a gas generator, a micro-thruster, a primer for use with a larger explosive material, and the like.Type: GrantFiled: February 14, 2012Date of Patent: February 21, 2017Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Luke M. Currano, Madan Dubey, Ronald G. Polcawich
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Patent number: 9297746Abstract: A reaction characteristic detector comprising a ladder assembly including a plurality of rungs, where each rung in the plurality of rungs comprises a reaction passage determiner spaced a distance from a point of an energetic material reaction initiation. Each reaction passage determiner has at least one characteristic that is configured to change in response to the reaction occurring proximate to the reaction passage determiner.Type: GrantFiled: December 1, 2011Date of Patent: March 29, 2016Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Steven J. Apperson, Christopher J. Morris, Luke J. Currano, Collin R. Becker, Madan Dubey
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Patent number: 9272426Abstract: According to embodiments, an optically-actuated mechanical device comprises at least one deformable section formed of: an element including an intrinsic stress differential or gradient, the stress tending to urge deformation of one portion relative to another portion; and an optically-sensitive material which is configured to (i) initially prevent deformation of the device, and (ii) upon sufficient heating by absorbing optical energy allows the element to deform. The devices may be incorporated into various devices and apparatuses for select, non-contact actuation using only optical energy, for example, via light, from one or more lasers. Methods for fabricating and actuating such devices are also disclosed.Type: GrantFiled: June 25, 2014Date of Patent: March 1, 2016Assignee: The Uniteed States of America as represented by the Secretary of the ArmyInventors: Christopher J. Morris, Kate E. Malachowski, David H. Gracias, Madan Dubey
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Publication number: 20150298322Abstract: According to embodiments, an optically-actuated mechanical device comprises at least one deformable section formed of: an element including an intrinsic stress differential or gradient, the stress tending to urge deformation of one portion relative to another portion; and an optically-sensitive material which is configured to (i) initially prevent deformation of the device, and (ii) upon sufficient heating by absorbing optical energy allows the element to deform. The devices may be incorporated into various devices and apparatuses for select, non-contact actuation using only optical energy, for example, via light, from one or more lasers. Methods for fabricating and actuating such devices are also disclosed.Type: ApplicationFiled: June 25, 2014Publication date: October 22, 2015Inventors: Christopher J. Morris, Kate E. Malachowski, David H. Gracias, Madan Dubey
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Publication number: 20140216288Abstract: Embodiments of energetic devices are provided herein. In some embodiments, an energetic device may include a substrate having a plurality of pores formed in a portion of the substrate; a plurality of carbon nanotubes disposed proximate the plurality of pores such that a reaction within one of the plurality of pores or the plurality of carbon nanotubes initiates a reaction within the other of the plurality of pores or the plurality of carbon nanotubes; a solid oxidizer disposed in the plurality of pores and the carbon nanotubes; and an initiator to initiate a reaction within one of the plurality of pores or the plurality of carbon nanotubes.Type: ApplicationFiled: February 6, 2013Publication date: August 7, 2014Applicant: U.S. Army Research Laboratory ATTN: RDRL-LOC-IInventors: Luke Currano, Madan Dubey, Ronald G. Polcawich
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Patent number: 8629480Abstract: A hetero-junction tunneling transistor having a first layer of p++ silicon germanium which forms a source for the transistor at one end. A second layer of n+ silicon material is deposited so that a portion of the second layer overlies the first layer and forms the drain for the transistor. An insulating layer and metallic gate for the transistor is deposited on top of the second layer so that the gate is aligned with the overlying portions of the first and second layers. The gate voltage controls the conduction between the source and the drain and the conduction between the first and second layers occurs by vertical tunneling between the layers.Type: GrantFiled: May 24, 2012Date of Patent: January 14, 2014Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Osama M. Nayfeh, Madan Dubey
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Publication number: 20130206290Abstract: A micro-explosive material is provided. The micro-explosive material can include a carbon nanotube and a solid oxidizer attached to the carbon nanotube. The carbon nanotube with the solid oxidizer attached thereto is operable to burn per an exothermic chemical reaction between the carbon nanotube and the solid oxidizer such that a controlled burn and/or an explosive burn is provided. The micro-explosive material can be used as a heat generator, a gas generator, a micro-thruster, a primer for use with a larger explosive material, and the like.Type: ApplicationFiled: February 14, 2012Publication date: August 15, 2013Inventors: Luke M. Currano, Madan Dubey, Ronald G. Polcawich
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Publication number: 20130143330Abstract: A reaction characteristic detector comprising a ladder assembly including a plurality of rungs, where each rung in the plurality of rungs comprises a reaction passage determiner spaced a distance from a point of an energetic material reaction initiation. Each reaction passage determiner has at least one characteristic that is configured to change in response to the reaction occurring proximate to the reaction passage determiner.Type: ApplicationFiled: December 1, 2011Publication date: June 6, 2013Inventors: Steven J. Apperson, Christopher J. Morris, Luke J. Currano, Collin R. Becker, Madan Dubey
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Publication number: 20120305891Abstract: Embodiments of graphene channel transistors and methods for producing same are provided herein. In some embodiments, a graphene channel transistor may include a substrate a having a source region, a drain region, and a dielectric material disposed between the source and drain regions; a channel region comprising a graphene layer disposed atop the dielectric material and partially atop the source and drain regions; and a composite gate electrode comprising an insulator layer disposed atop the graphene layer and a conductive layer disposed atop the insulator layer.Type: ApplicationFiled: May 24, 2012Publication date: December 6, 2012Inventors: Osama M. Nayfeh, Madan Dubey
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Publication number: 20120298960Abstract: A hetero-junction tunneling transistor having a first layer of p++ silicon germanium which forms a source for the transistor at one end. A second layer of n+ silicon material is deposited so that a portion of the second layer overlies the first layer and forms the drain for the transistor. An insulating layer and metallic gate for the transistor is deposited on top of the second layer so that the gate is aligned with the overlying portions of the first and second layers. The gate voltage controls the conduction between the source and the drain and the conduction between the first and second layers occurs by vertical tunneling between the layers.Type: ApplicationFiled: May 24, 2012Publication date: November 29, 2012Inventors: Osama M. Nayfeh, Madan Dubey
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Patent number: 6311003Abstract: An optical electronic integrated circuit (OEIC) having optical waveguides as device interconnects. An optical waveguide is formed by depositing, in an oxygen-free atmosphere, a film of semiconductor material on a semiconductor substrate at a temperature that substantially diminishes the porosity of the film and the diffusion of material from the substrate into the film. The semiconductor film, which has an index of refraction greater than that of the substrate, is etched to form the optical waveguide on the substrate. The substrate also supports a plurality of active optical devices between which the optical waveguide extends. The substrate is preferably formed from gallium-arsenide and the waveguide from germanium. The active devices may also include these materials as well as aluminum-gallium-arsenide.Type: GrantFiled: February 24, 1999Date of Patent: October 30, 2001Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Madan Dubey, Kenneth A. Jones, Weiyu Han, Lawrence C. West
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Patent number: 6051445Abstract: An optical electronic integrated (circuit (OEIC) having optical waveguides s device interconnects. An optical waveguide is formed by depositing, in an oxygen-free atmosphere, a film of semiconductor material on a semiconductor substrate at a temperature that substantially diminishes the porosity of the film and the diffusion of material from the substrate into the film. The semiconductor film, which has an index of refraction greater than that of the substrate, is etched to form the optical waveguide on the substrate. The substrate also supports a plurality of active optical devices between which the optical waveguide extends. The substrate is preferably formed from gallium-arsenide and the waveguide from germanium. The active devices may also include these materials as well as aluminum-gallium-arsenide. When using these materials, the germanium film is deposited in an oxygen-free environment at about 100 degrees centigrade.Type: GrantFiled: February 24, 1999Date of Patent: April 18, 2000Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Madan Dubey, Kenneth A. Jones, Weiyu Han, Lawrence C. West
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Patent number: 5917967Abstract: An optical electronic integrated circuit (OEIC) having optical waveguides as device interconnects. An optical waveguide is formed by depositing, in an oxygen-free atmosphere, a film of semiconductor material on a semiconductor substrate at a temperature that substantially diminishes the porosity of the film and the diffusion of material from the substrate into the film. The semiconductor film, which has an index of refraction greater than that of the substrate, is etched to form the optical waveguide on the substrate. The substrate also supports a to plurality of active optical devices between which the optical waveguide extends. The substrate is preferably formed from gallium-arsenide and the waveguide from germanium. The active devices may also include these materials as well as aluminum-gallium-arsenide. When using these materials, the germanium film is deposited in an oxygen-free environment at about 100 degrees centigrade.Type: GrantFiled: May 21, 1997Date of Patent: June 29, 1999Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Madan Dubey, Kenneth A. Jones, Weiyu Han, Lawrence C. West
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Patent number: 5811830Abstract: The present invention is achieved by layering a dielectric slab between a ground plane and a two dimensional quasi quantum well heterostructure and by switching between an unbiased state and a negative potential which is established between the quantum well heterostructure and the ground plane. In the unbiased state, the device supports wave propagation in the dielectric with a phase velocity similar to that of a wave propagating in a parallel plate waveguide. Upon application of the bias voltage, that is establishing a negative potential difference between contacts based on either side of the quantum well heterostructure, the conductivity of the quantum well decreases. Therefore, as the carrier wave propagates the wave interacts with a boundary similar to that of a dielectric-air interface. This new boundary condition, in turn, produces a faster phase velocity. Hence, toggling the bias modulates the quantum well conductivity which changes the phase velocity of the carrier wave.Type: GrantFiled: June 8, 1995Date of Patent: September 22, 1998Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Madan Dubey, Hong Liang Cui, Charles D. Hechtman, Norman J. Horing, George F. McLane