Patents Represented by Attorney Hillary T. Womack
  • Patent number: 5986036
    Abstract: A new holographic substrate utilizing flexible, optically transparent fluorinated polyimides. Said substrates have extremely low birefringence which results in a high signal to noise ratio in subsequent holograms. Specific examples of said fluorinated polyimides include 6FDA+APB and 6FDA+4BDAF.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: November 16, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul A. Gierow, William R. Clayton, Anne K. St. Clair
  • Patent number: 5948965
    Abstract: A means for detecting carbon monoxide which utilizes an un-heated catalytic material to oxidize carbon monoxide at ambient temperatures. Because this reaction is exothermic, a thermistor in contact with the catalytic material is used as a sensing element to detect the heat evolved as carbon monoxide is oxidized to carbon dioxide at the catalyst surface, without any heaters or external heating elements for the ambient air or catalytic element material. Upon comparison to a reference thermistor, relative increases in the temperature of the sensing thermistor correspond positively with an increased concentration of carbon monoxide in the ambient medium and are thus used as an indicator of the presence of carbon monoxide.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: September 7, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Billy T. Upchurch, George M. Wood, David R. Schryer, Bradley D. Leighty, Donald M. Oglesby, Erik J. Kielin, Kenneth G. Brown, Christine M. D'Ambrosia
  • Patent number: 5909905
    Abstract: A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors, weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 100.degree. C.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: June 8, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Joycelyn O. Simpson, Terry L. St. Clair
  • Patent number: 5891581
    Abstract: A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors, weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 100.degree. C.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: April 6, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Joycelyn O. Simpson, Terry L. St. Clair
  • Patent number: 5889139
    Abstract: Novel polyimide copolymers containing ether linkages were prepared by the reaction of an equimolar amount of dianhydride and a combination of diamines. The polyimide copolymers described herein possess the unique features of low moisture uptake, dimensional stability, good mechanical properties, and moderate glass transition temperatures. These materials have potential application as encapsulants and interlayer dielectrics.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: March 30, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Catharine C. Fay, Anne K. St. Clair
  • Patent number: 5840828
    Abstract: A polyimide fiber having textile physical property characteristics and the process of melt extruding same from a polyimide powder. Polyimide powder formed as the reaction product of the monomers 3,4'-ODA and ODPA, and endcapped with phthalic anhydride to control the molecular weight thereof, is melt extruded in the temperature range of 340.degree. C. to 360.degree. C. and at heights of 100.5 inches, 209 inches and 364.5 inches. The fibers obtained have a diameter in the range of 0.0068 inch to 0.0147 inch; a mean tensile strength in the range of 15.6 to 23.1 ksi; a mean modulus of 406 to 465 ksi; and a mean elongation in the range of 14 to 103%.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: November 24, 1998
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Terry L. St. Clair, Catharine C. Fay, Dennis C. Working
  • Patent number: 5753306
    Abstract: A method for creating a composite form of coating from a sprayable solution of soluble polyimides and particle materials that are uniformly dispersed within the solution is described. The coating is formed by adding a soluble polyimide to a solvent, then stirring particle materials into the solution. The composite solution is sprayed onto a substrate and heated in an oven for a period of time in order to partially remove the solvent. The process may be repeated until the desired thickness or characteristic of the coating is obtained. The polyimide is then heated to at least 495.degree. F. so that it is no longer soluble.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: May 19, 1998
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Sang Q. Tran