# US 2018/0024089 A1 · Nanoparticle-Based Gas Sensors and Methods of Using the Same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2018/0024089 A1
- Document ID: US20180024089A1
- Status: Published application
- Kind: A1
- Application number: 15/703,752
- Filed: 2017-09-13
- Published: 2018-01-25
- Earliest claimed: 2012-10-05
- Assignees: The Regents of the University of California
- Applicants: The Regents of the University of California
- Inventors: William Mickelson; Alex K. Zettl
- Web page: https://patentgrep.com/patent/US20180024089A1

## CPC

- G01N 27/403: Cells and electrode assemblies
- G01N 27/127: {comprising nanoparticles}
- G01N 33/0044: {Sulphides, e.g. H2S}
- 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

Gas sensors are provided. The gas sensors include a gas sensing element having metal oxide nanoparticles and a thin-film heating element. Systems that include the gas sensors, as well as methods of using the gas sensors, are also provided. Embodiments of the present disclosure find use in a variety of different applications, including detecting whether an analyte is present in a gaseous sample.

## Claims

### Claim 1

A gas sensor comprising:
a gas sensing element comprising metal oxide nanoparticles;
a thin-film heating element; and
a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element.

### Claim 2 (depends on 1)

The gas sensor of claim 1, wherein the gas sensing element comprises a first electrode and a second electrode with the metal oxide nanoparticles disposed between the first electrode and the second electrode.

### Claim 3 (depends on 1)

The gas sensor of claim 1, wherein the metal oxide nanoparticles comprise tungsten oxide nanoparticles and the gas sensor is configured to detect hydrogen sulfide.

### Claim 4 (depends on 3)

The gas sensor of claim 3, wherein the metal oxide nanoparticles have an average diameter of 100 nm or less.

### Claim 5 (depends on 1)

The gas sensor of claim 1, wherein the thin-film heating element comprises polysilicon.

### Claim 6 (depends on 1)

The gas sensor of claim 1, further comprising an insulation layer between the gas sensing element and the thin-film heating element.

### Claim 7 (depends on 6)

The gas sensor of claim 6, wherein the insulation layer comprises silicon nitride.

### Claim 8 (depends on 1)

The gas sensor of claim 1, wherein the gas sensor is configured to have a thermal efficiency ranging from 30° C./mW to 200° C./mW.

### Claim 9 (depends on 1)

The gas sensor of claim 1, wherein the gas sensor is configured to have a limit of detection of 1 ppm or less.

### Claim 10

A gas sensor system comprising:
one or more gas sensors, wherein each gas sensor comprises:
gas sensing element comprising metal oxide nanoparticles;
a thin-film heating element; and
a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element.

### Claim 11 (depends on 10)

The gas sensor system of claim 10, wherein the gas sensor system comprises an array of 6 or more gas sensors.

### Claim 12

(canceled)

### Claim 13 (depends on 11)

The gas sensor system of claim 11, wherein the array has a length of 3 mm or less and a width of 3 mm or less.

### Claim 14 (depends on 10)

The gas sensor system of claim 10, further comprising a controller configured to repeatedly activate and deactivate the thin-film heating element over a period of time.

### Claim 15 (depends on 14)

The gas sensor system of claim 14, wherein the controller is configured to activate the thin-film heating element with a duty cycle of 20% or less.

### Claim 16 (depends on 14)

The gas sensor system of claim 14, wherein the controller is configured to activate the thin-film heating element with a frequency of 0.1 Hz or more.

### Claim 17

A method of detecting whether an analyte is present in a gaseous sample, the method comprising:
contacting a gaseous sample to a gas sensor to produce a signal, the gas sensor comprising:
a gas sensing element comprising metal oxide nanoparticles;
a thin-film heating element; and
a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element; and
analyzing the signal to determine whether the analyte is present in the gaseous sample.

### Claim 18 (depends on 17)

The method of claim 17, further comprising heating the gas sensing element with the thin-film heating element during the contacting.

### Claim 19 (depends on 18)

The method of claim 18, wherein the heating comprises repeatedly activating and deactivating the thin-film heating element over a period of time.

### Claim 20 (depends on 17)

The method of claim 17, further comprising determining the concentration of the analyte in the gaseous sample based on the signal.

### Claim 21 (depends on 20)

The method of claim 20, further comprising activating an alarm if the concentration of the analyte is greater than a threshold value.