Abstract: Methods, systems and a self-sensing valve assembly are described for monitoring seal life. The method includes providing a valve assembly movable from an open position to a closed position and including a seal seated within the valve and in contact with a surface of the valve assembly, wherein when the seal is in operation it is subject to degradation. At least one sensor is placed for measuring micro strain on a surface of the valve assembly or within the valve assembly. The valve assembly is placed in an operation wherein the seal is subject to degradation and the operation of the valve assembly is initiated.

Abstract: Temperature measurements are critical in gas turbine engine design but difficult to obtain due to the extreme environment. Temperature indicating paints (thermal paints) have been used for decades to map maximum temperature fields on superalloy components but have numerous weaknesses. Disclosed herein are novel glass ceramic thermal paints that undergo viscous flow sintering to indicate temperatures up to 1000° C., with high resolution (±5° C.), by an optical transition. Disclosed paint formulations are designed to adhere to Nickel-based superalloys or SiC—SiC ceramic matrix composites (CMC) by closely matching coefficients of thermal expansion and may function for times above 60 hours. By utilizing automation and a UV:VIS spectrometer, quantitative temperature maps can be generated for easy comparison to theoretical models. A transient sintering energy model is disclosed to recover full thermal history information.

Abstract: Methods and apparatuses for highly sensitive detection of analytes using redox reactions. A library of heat reactions of analytes of interest with a variety of catalysts at a variety of temperatures is prepared. An array of sensors with low thermal mass heating elements is prepared, depositing the same or different catalysts, such as metal oxide catalysts that have multiple oxidation states, on each heating element. The low thermal mass heating elements are preferably not in thermal contact with a substrate, or a low mass substrate is used. The array is exposed to a sample at various temperatures. The sign and magnitude of the heat effect of the redox reaction of compounds in the sample or their decomposition products with each catalyst is measured and compared with the library. The catalysts and temperatures are chosen so that the desired analytes have a unique pattern of heat effect signs and magnitudes when reacted with those catalysts at those temperatures.

Abstract: Ultrasensitive, ultrathin thermodynamic sensing platforms for the detection of chemical compounds at trace levels are disclosed. Embodiments of the ultrathin sensor comprise substrate, adhesion, microheater, and catalyst layers. A sensor array may include a plurality of sensors each having a different catalyst. When a sensor array exposed to an analyte, each of the various sensors of the array may experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously-obtained reaction results may be used to determine information on the analyte. Advantageously, these ultrathin vapor sensors utilize less power and provide greater sensitivity, and may be used to detect and identify analytes at the PPT level. Specialized sensors configured to detect analytes falling into a certain category (e.g., explosives, drugs and narcotics, biomarkers, etc.

Abstract: Ultrasensitive, decoupled thermodynamic sensing platforms for the molecular-level detection of target analytes are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other-known systems, and may be used to detect and identify a single molecule of an analyte.

Abstract: Ultrasensitive, ultrathin thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed. Embodiments of the ultrathin vapor sensor comprise a substrate layer, an adhesion layer, a metallic microheater layer, and a catalyst layer. A sensor array may be provided including a plurality of sensors each having a different catalyst. When a sensor array exposed to an analyte, each of the various ultrathin vapor sensors of the array may experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously-obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, these ultrathin vapor sensors utilize less power and provide greater sensitivity than known systems, and may be used to detect and identify analytes at the parts per trillion level. Specialized sensors configured to detect analytes falling into a certain category (e.g.

Abstract: Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.

Abstract: Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.

Abstract: Methods, systems and a self-sensing valve assembly are described for monitoring seal life. The method includes providing a valve assembly movable from an open position to a closed position and including a seal seated within the valve and in contact with a surface of the valve assembly, wherein when the seal is in operation it is subject to degradation. At least one sensor is placed for measuring micro strain on a surface of the valve assembly or within the valve assembly. The valve assembly is placed in an operation wherein the seal is subject to degradation and the operation of the valve assembly is initiated.

Abstract: A resistance temperature detector (RTD) that uses a ceramic matrix composite (CMC), such as a silicon carbide fiber-reinforced silicon carbide matrix, as an active temperature sensing element, which can operate at temperatures greater than 1000° C. or even 1600° C. Conductive indium tin oxide or a single elemental metal such as platinum is deposited on a dielectric or insulating layer such as mullite or an environmental barrier coating (EBC) on the substrate. Openings in the layer allow etching of the CMC surface in order to make high quality ohmic contacts with the conductive material, either directly or through a silicide diffusion barrier such as ITO. The RTD can measure both temperature and strain of the CMC. The use of an EBC, which typically is deposited on the CMC by the manufacturer, as the insulating or dielectric layer can be extended to other devices such as strain gages and thermocouples that use the CMC as a sensing element. The EBC can be masked and etched to form the openings.

Abstract: A gas sensor system is disclosed for detection of a compound that decomposes upon exposure to a metal oxide catalyst. The gas sensor system includes a sensor which includes a microheater, and a metal oxide catalyst that covers the microheater. The gas sensor system includes a pre-concentrator upstream from the sensor that lowers the limit of the detection of a compound.

Abstract: A temperature measurement system capable of operating in harsh environments including a temperature sensor having an antenna, diode, and dielectric layer disposed on the object of interest is provided, wherein the antenna includes a buried portion that extends through and is electrically coupled to the object of interest, and an exposed portion disposed upon an outer surface of the dielectric layer and the diode is coupled between the object of interest and the exposed portion of the antenna. The antenna is configured to receive interrogating signals from a transmitter, and to transmit response signals corresponding to the resonant frequency of the temperature sensor and its harmonics, which are indicative of the measured temperature of the object of interest. A receiver detects the response signals and correlates the frequency to a known temperature response of the dielectric material. Methods of making and using the temperature measurement system are also provided.

Abstract: A temperature measurement system capable of operating in harsh environments including a temperature sensor having an antenna, diode, and dielectric layer disposed on the object of interest is provided, wherein the antenna includes a buried portion that extends through and is electrically coupled to the object of interest, and an exposed portion disposed upon an outer surface of the dielectric layer and the diode is coupled between the object of interest and the exposed portion of the antenna. The antenna is configured to receive interrogating signals from a transmitter, and to transmit response signals corresponding to the resonant frequency of the temperature sensor and its harmonics, which are indicative of the measured temperature of the object of interest. A receiver detects the response signals and correlates the frequency to a known temperature response of the dielectric material. Methods of making and using the temperature measurement system are also provided.

Abstract: A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400° C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.

Abstract: A temperature measurement system capable of operating in harsh environments including a temperature sensor having an antenna, diode, and dielectric layer disposed on the object of interest is provided, wherein the antenna includes a buried portion that extends through and is electrically coupled to the object of interest, and an exposed portion disposed upon an outer surface of the dielectric layer and the diode is coupled between the object of interest and the exposed portion of the antenna. The antenna is configured to receive interrogating signals from a transmitter, and to transmit response signals corresponding to the resonant frequency of the temperature sensor and its harmonics, which are indicative of the measured temperature of the object of interest. A receiver detects the response signals and correlates the frequency to a known temperature response of the dielectric material. Methods of making and using the temperature measurement system are also provided.

Abstract: A superalloy article which comprises a substrate comprised of a superalloy, a bond coat comprised of MCrAlY wherein M is a metal selected from the group consisting of cobalt, nickel and mixtures thereof applied onto at least a portion of the substrate and a ceramic top coat applied over at least a portion of the bond coat. The bond coat is exposed to a temperature of within the range of between about 1600-1800° F. subsequent to its application onto the substrate.

Abstract: A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500° C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.

Abstract: A superalloy article which comprises a substrate comprised of a superalloy, a bond coat comprised of MCrAlY wherein M is a metal selected from the group consisting of cobalt, nickel and mixtures thereof applied onto at least a portion of the substrate and a ceramic top coat applied over at least a portion of the bond coat. The bond coat is exposed to a temperature of within the range of between about 1600-1800° F. subsequent to its application onto the substrate.

Abstract: A nano-composite material having a high electrical conductivity and a high Seebeck coefficient and low thermal conductivity. The nano-composite material is capable of withstanding high temperatures and harsh conditions. These properties make it suitable for use as both a thermal barrier coating for turbine blades and vanes and a thermoelectric generator to power high temperature electronics, high temperature wireless transmitters, and high temperature sensors. Unique to these applications is that the thermal barrier coatings can act as a temperature sensor and/or a source of power for other sensors or high temperature electronics and wireless transmitters.

Abstract: A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500° C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.