Hughes Aircraft Company

Hrl Laboratories, LLC

Hughes Electronics Corporation

Hughes Aircraft

Camille I Van Ast

Leroy J Miller

Frederick G Yamagishi

Chan S Bak

Thomas B Stanford

Thomas B Stanford, Jr

A sensor and method for detecting biological and chemical agents comprising metal interdigitized electrodes coated with hybrid polymer-based conducting film and an instrument for applying electrical voltage to the electrodes and registering the change in electrical current. The hybrid film also comprises indicator biomolecules encapsulated within the film or attached to it. The bioindicator molecules preferably comprise enzyme acetylcholinesterase. When these indicator biomolecules come in a contact with a pathogen, chemical and/or morphological changes occur in the film and electrical current flowing through the electrodes is modulated. The pathogen comprise inhibitors of enzymes, preferably organophosphates, thiophosphates or phosphonates. The change in current indicates the presence of a biological and chemical agent and is registered.

Sensors with variable response behavior

A sensor and method for detecting biological and chemical agents comprising metal interdigitized electrodes coated with hybrid polymer-based conducting film and an instrument for applying electrical voltage to the electrodes and registering the change in voltage. The hybrid film also comprises indicator biomolecules encapsulated within the film or attached to it. When these indicator biomolecules come in a contact with a biological and chemical agent, morphological changes occur in the film and electrical current flowing through the electrodes is modulated. The change in current indicates the presence of a biological and chemical agent and is registered.

Sensor for chemical and biological materials

A novel, inexpensive sensor and method for detecting volatile compounds in the gas phase at concentrations of less than about 500 ppm in ambient air are provided. The sensor comprises (a) a dielectric substrate having a major surface; (b) a pair of electrically conductive electrodes disposed on the major surface of the substrate; and (c) a conductive polymer covering the pair of electrically conductive electrodes, with the conductive polymer doped with appropriate dopants in measurable excess of that stoichiometrically required to change the conductive polymer from a neutral state to a charged state to provide requisite conductivity. A method for making the sensor is provided, as is a method of use of the sensor which relates to its use in a monitoring system comprising a means for measuring the conductivity of the sensor connected to a warning means for providing an indication when the conductivity reaches a predetermined level. Contemplated specific methods of use include the detection of fugitive emissions in chemical plant environments; the detection of certain pollutants in vehicle exhaust; and the detection of certain pollutants near chemical handling operations, such as painting operations.

Volatile organic compound sensors

A method is provided for preparing the surface of a cyanate ester polymer or composite for metal plating. The surface is treated with a preheated solution containing a compound selected from the group consisting of at least one quaternary ammonium hydroxide and at least one primary amine. The method of the invention operates to improve adhesion between the treated surface and a subsequently plated metal, such that the resulting cyanate ester polymer or composite may replace certain metallic components in such applications as aircraft, spacecraft, and automobiles given its highly conductive metallic coating.

Preparation of cyanate ester polymers and composites for metal plating

A novel, inexpensive sensor (10) for detecting volatile hydrocarbons and other solvent vapors detects leaks in the fittings and valves of petroleum refineries and chemical manufacturing and processing plants. The sensor comprises (a) a dielectric substrate (12) having a major surface; (b) a pair of interdigitated, electrically conductive electrodes (14a, 14b) disposed on the major surface of the substrate; and (c) a composite coating (16) covering the interdigitated electrodes and comprising (1) a conductive polymer, and (2) a dielectric polymer with an affinity for the solvent vapors to be detected.

Method for detecting fugitive emissions

Reversible sensor for detecting solvent vapors

A grating (22) of narrow parallel ridges (24) is formed in the surface (26) of a substrate (20) made of a hard material such as silicon dioxide. Metal (40) is deposited onto the grating (22) perpendicular to the ridges (24) at an angle of approximately 45.degree. to the surface (26) of the grating such that the metal (40) is deposited onto the top (24a) and one of the sides (24b) of the each of the ridges (24) to form generally L-shaped metal strips (12') thereon. The metal strips (12') are cut at periodic intervals along the ridges (24) to produce anisometric metal needles (12). The substrate (20) is immersed in a dielectric fluid (14), and ultrasonic energy is applied to cause the needles (12) to release from the substrate (20) into suspension in the fluid (14). The L-shape of the needles (12) makes them resistant to bending. The suspension (10) has birefringent properties similar to liquid crystals, but may be electrically switched at much higher speed. The index of refraction of the suspension (10) varies in accordance with the alignment of the needles (12), thereby enabling the direction and phase of an electromagnetic wave propagating through the suspension (10) to be controlled by varying the magnitude of the applied electric field.

Anisometric metal needles with L-shaped cross-section

A sensor for monitoring the water content and the acid content in the presence of water in nonaqueous media can be incorporated into a monitoring system for monitoring the quality of nonaqueous fluids in equipment or vehicles. The sensor comprises an insulating substrate; electrodes formed on the substrate in an interdigitated pattern; and a conductive polymer deposited over the interdigitated electrodes which bridges between adjacent digits of the electrodes. The monitoring system incorporating the sensor comprises a control module for measuring the conductivity of the sensor. The control module is preprogrammed to compare the measured conductivity to a predetermined level indicative of an unacceptable level of degradation. The sensor is made by depositing electrodes on an insulating substrate; depositing a conductive polymer over the electrodes in an amount sufficient to bridge between the electrodes; and neutralizing the conductive polymer to an insulating form. A method of sensing water and acid in the presence of water in nonaqueous media exposes an insulating form of a conductive polymer to a nonaqueous medium and monitors the conductivity of said conductive polymer, as the nonaqueous medium is used. The conductive polymer reversibly increases conductivity in measurable amounts with increasing acid and/or water content due to protonation by the acid or hydration by the water.

Device and method for sensing water and/or acid in the presence of water

A grating (22) of narrow parallel ridges (24) is formed in the surface (26) of a substrate (20) made of a hard material such as silicon dioxide. Metal (40) is deposited onto the grating (22) perpendicular to the ridges (24) at an angle of approximately 45.degree. to the surface (26) of the grating such that the metal (40) is deposited onto the top (24a) and one of the sides (24b) of the each of the ridges (24) to form generally L-shaped metal strips (12') thereon. The metal strips (12') are cut at periodic intervals along the ridges (24) to produce anisometric metal needles (12). The substrate (20) is immersed in a dielectric fluid (14), and ultrasonic energy is applied to cause the needles (12) to release from the substrate (20) into suspension in the fluid (14). The L-shape of the needles (12) makes them resistant to bending. The suspension ( 10) has birefringent properties similar to liquid crystals, but may be electrically switched at much higher speed. The index of refraction of the suspension (10) varies in accordance with the alignment of the needles (12), thereby enabling the direction and phase of an electromagnetic wave propagating through the suspension (1) to be controlled by varying the magnitude of the applied electric field.

Method of fabricating anisometric metal needles and birefringent

A grating (22) of narrow parallel ridges (24) is formed in the surface (26) of a substrate (20) made of a hard material such as silicon dioxide. Metal (40) is deposited onto the grating (22) perpendicular to the ridges (24) at an angle of approximately 45.degree. to the surface (26) of the grating such that the metal (40) is deposited onto the top (24a) and one of the sides (24b) of the each of the ridges (24) to form generally L-shaped metal strips (12') thereon. The metal strips (12') are cut at periodic intervals along the ridges (24) to produce anisometric metal needles (12). The substrate (20) is immersed in a dielectric fluid (14), and ultrasonic energy is applied to cause the needles (12) to release from the substrate (20) into suspension in the fluid (14). The L-shape of the needles (12) makes them resistant to bending. The suspension ( 10) has birefringent properties similar to liquid crystals, but may be electrically switched at much higher speed. The index of refraction of the suspension (10) varies in accordance with the alignment of the needles (12), thereby enabling the direction and phase of an electromagnetic wave propagating through the suspension (10) to be controlled by varying the magnitude of the applied electric field.

A composite material having droplets of a liquid crystal material in a matrix of a coploymer of a multifunctional acrylate, or a mixture of different multifunctional acrylates, and a multifunctional mercaptan is prepared by photopolymerization. The liquid crystal material is initially mixed with a multifunctional acrylate monomer, a multifunctional mercaptan, and a photoinitiator to form a solution. The solution is exposed to ultraviolet light, whereupon the multifunctional acrylate monomer and multifunctional mercaptan copolymerize in a step reaction, and the liquid crystal separates from the copolymer as droplets dispersed throughout the copolymer matrix. The resulting material is placed between transparent, electrically conducting plates to form an electro-optic display device.

Growing community of inventors

Newbury Park, CA, United States of America

Camille I Van Ast