# US 10,481,090 B2 · Plasmonic non-dispersive infrared gas sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,090 B2 - Document ID: US10481090B2 - Status: Granted - Kind: B2 - Application number: 15/918,638 - Filed: 2018-03-12 - Published: 2019-09-12 - Granted: 2019-11-19 - Earliest claimed: 2018-03-12 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Abram L. Falk; Damon B. Farmer; Shu-Jen Han - Web page: https://patentgrep.com/patent/US10481090B2 ## CPC - G01N 21/554: {detecting the surface plasmon resonance of nanostructured metals, e.g. localised surface plasmon resonance} - G01N 21/3504: for analysing gases, e.g. multi-gas analysis - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Differential, plasmonic, non-dispersive infrared gas sensors are provided. In one aspect, a gas sensor includes: a plasmonic resonance detector including a differential plasmon resonator array that is resonant at different wavelengths of light; and a light source incident on the plasmonic resonance detector. The differential plasmon resonator array can include: at least one first set of plasmonic resonators interwoven with at least one second set of plasmonic resonators, wherein the at least one first set of plasmonic resonators is configured to be resonant with light at a first wavelength, and wherein the at least one second set of plasmonic resonators is configured to be resonant with light at a second wavelength. A method for analyzing a target gas and a method for forming a plasmonic resonance detector are also provided. ## Claims ### Claim 1 A gas sensor, comprising: a plasmonic resonance detector comprising a differential plasmon resonator array that is resonant at different wavelengths of light; and a light source incident on the plasmonic resonance detector, wherein the light source comprises: a first electrode; a second electrode; a plurality of plasmonic resonators between the first electrode and the second electrode; and a voltage source configured to apply a voltage across the first electrode and the second electrode causing current to pass through the plasmonic resonators. ### Claim 2 (depends on 1) The gas sensor of claim 1, further comprising: an enclosure, wherein the plasmonic resonance detector and the light source are housed within the enclosure. ### Claim 3 (depends on 1) The gas sensor of claim 1, wherein the enclosure comprises: an air inlet; and an air outlet. ### Claim 4 (depends on 1) The gas sensor of claim 1, wherein the plurality of plasmonic resonators comprise aligned carbon nanotubes. ### Claim 5 (depends on 1) The gas sensor of claim 1, wherein the differential plasmon resonator array comprises: at least one first set of plasmonic resonators interwoven with at least one second set of plasmonic resonators, wherein the at least one first set of plasmonic resonators is configured to be resonant with light at a first wavelength, and wherein the at least one second set of plasmonic resonators is configured to be resonant with light at a second wavelength. ### Claim 6 (depends on 5) The gas sensor of claim 5, wherein the differential plasmon resonator array further comprises: at least one third set of resonators interwoven with the at least one first set of plasmonic resonators and the at least one second set of plasmonic resonators, wherein the at least one third set of plasmonic resonators is configured to be resonant with light at a third wavelength. ### Claim 7 (depends on 6) The gas sensor of claim 6, wherein the first wavelength corresponds to a peak absorption wavelength of a first target gas, and wherein the second wavelength corresponds to a reference wavelength. ### Claim 8 (depends on 7) The gas sensor of claim 7, wherein the third wavelength corresponds to a peak absorption wavelength of a second target gas. ### Claim 9 (depends on 5) The gas sensor of claim 5, wherein the differential plasmon resonator array comprises: a first set of ribbons of carbon nanotubes having a length L1 interwoven with a second set of ribbons of carbon nanotubes having a length L2, wherein the carbon nanotubes of the length L1 are configured to be resonant with light at the first wavelength, and wherein the carbon nanotubes of the length L2 are configured to be resonant with light at the second wavelength. ### Claim 10 (depends on 9) The gas sensor of claim 9, further comprising: first metal contacts to the first set of ribbons of carbon nanotubes having the length L1; and second metal contacts to the second set of ribbons of carbon nanotubes having the length L2. ### Claim 11 (depends on 5) The gas sensor of claim 5, wherein the differential plasmon resonator array comprises: a first set of split-ring resonators having a diameter D1 interwoven with a second set of split-ring resonators having a diameter D2, wherein the split-ring resonators having the diameter D1 are configured to be resonant with light at the first wavelength, and wherein the split-ring resonators having the diameter D2 are configured to be resonant with light at the second wavelength. ### Claim 12 (depends on 11) The gas sensor of claim 11, wherein the first set of split-ring resonators and the second set of split-ring resonators are each formed from a material selected from the group consisting of: gold (Au), titanium nitride (TiN), graphene, and combinations thereof. ### Claim 13 A method for analyzing a target gas, comprising the steps of: illuminating the target gas with light from a light source, wherein the light is incident on a plasmonic resonance detector comprising a differential plasmon resonator array having at least one first set of plasmonic resonators interwoven with at least one second set of plasmonic resonators, wherein the at least one first set of plasmonic resonators is configured to be resonant with the light at a first wavelength corresponding to a peak absorption wavelength of the target gas, wherein the at least one second set of plasmonic resonators is configured to be resonant with the light at a second wavelength corresponding to a reference wavelength, wherein the differential plasmon resonator array comprises a first set of ribbons of carbon nanotubes having a length L1 interwoven with a second set of ribbons of carbon nanotubes having a length L2, wherein the carbon nanotubes of the length L1 are configured to be resonant with the light at the first wavelength, and wherein the carbon nanotubes of the length L2 are configured to be resonant with the light at the second wavelength; absorbing the light by the at least one first set of plasmonic resonators and the at least one second set of plasmonic resonators, wherein the light at the first wavelength incident on the at least one first set of plasmonic resonators is dependent on an amount of the light at the first wavelength absorbed by the target gas; generating a photocurrent signal I1 in the at least one first set of plasmonic resonators and a photocurrent signal I2 in the at least one second set of plasmonic resonators; and determining a concentration of the target gas using I1-I2. ### Claim 14 A method for forming a plasmonic resonance detector, comprising the step of: forming at least one first set of plasmonic resonators interwoven with at least one second set of plasmonic resonators, wherein the at least one first set of plasmonic resonators is configured to be resonant with light at a first wavelength corresponding to a peak absorption wavelength of a target gas, and wherein the at least one second set of plasmonic resonators is configured to be resonant with light at a second wavelength corresponding to a reference wavelength, wherein the method further comprises the steps of: forming a film of aligned carbon nanotubes on a substrate; patterning the film of aligned carbon nanotubes into a first set of ribbons of carbon nanotubes having a length L1 interwoven with a second set of ribbons of carbon nanotubes having a length L2, wherein the carbon nanotubes of the length L1 are configured to be resonant with light at the first wavelength, and wherein the carbon nanotubes of the length L2 are configured to be resonant with light at the second wavelength; and forming contacts to the first set of ribbons of carbon nanotubes and the second set of ribbons of carbon nanotubes.