The United States of America As Represented by the United States

The United States of America As Represented by the Administrator of the

United States of America As Represented by the Administrator of Nasa

Purnell Hopson, Jr

Vincent B Cruz

Mark Sheplak

Ralph M Stephens

Eric F Spina

Catherine B McGinley

Allan J Zuckerwar

Nancy M Holloway

Frank W Cuomo

John J Chapman

Sang Q Tran

William E Robbins

A miniature, multi-channel, electronically scanned pressure measuring device uses electrostatically bonded silicon dies in a multi-element array. These dies are bonded at specific sites on a glass, pre-patterned substrate. Thermal data is multiplexed and recorded on each individual pressure measuring diaphragm. The device functions in a cryogenic environment without the need of heaters to keep the sensor at constant temperatures.

Multi-channel electronically scanned cryogenic pressure sensor and method for making same

A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

Method of forming micro-sensor thin-film anemometer

Micro-sensor thin-film anemometer

The invention comprises a method of forming a multi-element, thin hot film sensor on a polyimide film. The sensor is formed by first cleaning one surface of the polyimide. Then, under a continuous vacuum, the surface is simultaneously cleaned by ion bombardment while nickel is deposited by evaporation. The ion beam cleaning is discontinued and copper is then deposited to an initial thickness by evaporation without a break in the vacuum. The vacuum is then removed and a final thickness of copper is deposited by plating. Sensor patterns are then defined in the nickel and copper layers using conventional photolithography and etching techniques.

Method of forming multi-element thin hot film sensors on polyimide film

The invention is a method of forming a multiple layer dielectric for use in a hot-film laminar separation sensor 21. The multiple layer dielectric substrate is formed by depositing a first layer 22 of a thermoplastic polymer such as on an electrically conductive substrate such as the metal surface 23 of a model 24 to be tested under cryogenic conditions and high Reynolds numbers. Next, a second dielectric layer 26 of fused silica is formed on the first dielectric layer 22 of thermoplastic polymer. A resistive metal film is deposited on selected areas of the multiple layer dielectric substrate to form one or more hot-film sensor elements 27 to which aluminum electrical circuits 28 deposited upon the multiple layered dielectric substrate are connected.

Method of forming a multiple layer dielectric and a hot film sensor

A fiber optic microphone is provided for measuring fluctuating pressures. An optical fiber probe having at least one transmitting fiber for transmitting light to a pressure-sensing membrane and at least one receiving fiber for receiving light reflected from a stretched membrane is provided. The pressure-sensing membrane may be stretched for high frequency response. Further, a reflecting surface of the pressure-sensing membrane may have dimensions which substantially correspond to dimensions of a cross section of the optical fiber probe. Further, the fiber optic microphone can be made of materials for use in high temperature environments, for example greater than 1000.degree. F. A fiber optic probe is also provided with a backplate for damping membrane motion. The backplate further provides a means for on-line calibration of the microphone.

High temperature fiber optic microphone having a pressure-sensing

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Seaford, VA, United States of America

Purnell Hopson, Jr