# US 10,871,405 B2 · Indicator device and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,405 B2 - Document ID: US10871405B2 - Status: Granted - Kind: B2 - Application number: 15/607,858 - Filed: 2017-05-30 - Published: 2018-12-06 - Granted: 2020-12-22 - Earliest claimed: 2017-05-30 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Paul G. Vahey - Web page: https://patentgrep.com/patent/US10871405B2 ## CPC - G01K 11/16: of organic materials - G01J 5/0887: {Integrating cavities mimicking black bodies, wherein the heat propagation between the black body and the measuring element does not occur within a solid; Use of bodies placed inside the fluid stream for measurement of the temperature of gases; Use of the reemission from a surface, e.g. reflective surface; Emissivity enhancement by multiple reflections} - G01J 5/58: using absorption; using extinction effect - G01J 5/601: {using spectral scanning} - G01K 3/04: in respect of time - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) ## Abstract An indicator device including a protective layer, an optically reflective layer, a polymeric material layer disposed between and coupling the protective layer to the optically reflective layer, and a dye disposed within the polymeric material layer, the dye being sensitive to external stimuli. ## Claims ### Claim 1 An indicator device for non-destructive evaluation of external stimuli on a part, the indicator device comprising: a protective layer; an optically reflective layer; a polymeric material layer disposed between and coupling the protective layer to the optically reflective layer; and a dye disposed within the polymeric material layer, the dye being sensitive to external stimuli; wherein the optically reflective layer is configured to optically isolate the dye and remove background noise generated by the part so as to improve a signal-to-noise ratio of the indicator device. ### Claim 2 (depends on 1) The indicator device of claim 1 wherein, the polymeric material layer comprises a pressure sensitive adhesive. ### Claim 3 (depends on 1) The indicator device of claim 1, wherein the optically reflective layer includes a first side and a second side opposite the first side, and the polymeric material layer is disposed on the first side, the indicator device further comprising a second polymeric material layer coupled to the second side of the optically reflective layer. ### Claim 4 (depends on 1) The indicator device of claim 1, wherein the protective layer comprises a fluoropolymer layer. ### Claim 5 (depends on 1) The indicator device of claim 1, wherein the protective layer comprises a film. ### Claim 6 (depends on 1) The indicator device of claim 1, wherein the optically reflective layer comprises a film. ### Claim 7 An indicator device comprising: an optically reflective layer; and a plurality of sensor elements disposed on the optically reflective layer, at least one of the plurality of sensor elements including a protective layer; a polymeric material layer disposed between and coupling the protective layer to the optically reflective layer; and a dye disposed within the polymeric material layer, the dye being sensitive to external stimuli; wherein the plurality of sensor elements are arranged on the optically reflective layer in a repeating pattern of sensor elements. ### Claim 8 (depends on 7) The indicator device of claim 7, wherein the at least one of the plurality of sensor elements includes: a first sensor element, the dye of the first sensor element having a first predetermined dye characteristic, and a second sensor element, the dye of the second sensor element having a second predetermined dye characteristic different than the first predetermined dye characteristic. ### Claim 9 (depends on 7) The indicator device of claim 7 wherein, the polymeric material layer comprises a pressure sensitive adhesive. ### Claim 10 (depends on 7) The indicator device of claim 7, wherein the optically reflective layer includes a first side and a second side opposite the first side, and the polymeric material layer is disposed on the first side, the indicator device further comprising a second polymeric material layer coupled to the second side of the optically reflective layer. ### Claim 11 (depends on 10) The indicator device of claim 10, wherein the second polymeric material layer comprises a pressure sensitive adhesive. ### Claim 12 (depends on 7) The indicator device of claim 7, wherein the plurality of sensor elements are discrete sensor elements. ### Claim 13 (depends on 7) The indicator device of claim 7, wherein the protective layer comprises a film. ### Claim 14 (depends on 7) The indicator device of claim 7, wherein the optically reflective layer comprises a film. ### Claim 15 (depends on 7) The indicator device of claim 7, wherein the protective layer comprises a fluoropolymer layer. ### Claim 16 (depends on 15) The indicator device of claim 15, wherein the fluoropolymer layer comprises ethylene tetrafluoroethylene. ### Claim 17 (depends on 7) The indicator device of claim 7, wherein: the dye is a thermally sensitive dye and the indicator device comprises a temperature indicator; or the dye is sensitive to mechanical forces and the indicator device comprises one of an impact force indicator, a stress indicator, or a strain indicator. ### Claim 18 A method for measuring a determinable quantity, the method comprising: coupling an indicator device to a surface of a part, where the indicator device includes at least one sensor element having a protective layer, an optically reflective layer that removes background noise generated by the part, a polymeric material layer disposed between and coupling the protective layer to the optically reflective layer, and a dye disposed within the polymeric material layer, the dye being sensitive to external stimuli; and interrogating the indicator device in a visible spectrum with one or more of absorbance spectroscopy, fluorescence spectroscopy, reflectance spectroscopy, transmission spectroscopy, and Raman spectroscopy to determine a value of the determinable quantity affecting the part. ### Claim 19 (depends on 18) The method of claim 18, wherein the dye is a thermally sensitive dye and the determinable quantity affecting the part comprises a maximum temperature to which the part was exposed. ### Claim 20 (depends on 18) The method of claim 18, wherein the dye is sensitive to mechanical forces and the determinable quantity affecting the part comprises an impact force, a stress, or a strain.