Humidity sensor and sensor element

• US 9,562,872 B2
• Filed: 05/13/2013
• Issued: 02/07/2017
• Est. Priority Date: 05/29/2012
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Gryska, Stefan H., Lewinski, Krzysztof A., Palazzotto, Michael C.
• Primary Examiner(s): Tankersley, Blake A
• Application Number:
  US14/399,381
• Publication Number:
  US 20150153296A1
• Time in Patent Office: 1,366 Days
• US Class Current: 1/1
• CPC Class Codes: G01N 27/121 for determining moisture content, e.g. humidity, of the fluid moisture content of the tested material G01N27/048
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: G01N 27/225 by using hygroscopic materials

Abstract

A humidity sensor element includes a dielectric substrate, a nonporous conductive electrode disposed on the dielectric substrate, a permeable conductive electrode having a thickness in a range of from 4 to 10 nanometers and permeable by water vapor, and a detection layer disposed between the nonporous conductive electrode and the permeable conductive electrode. Both conductive electrodes have respective conductive leads attached thereto. The detection layer includes a sulfonated copolymer including monomeric units comprising (I) and (II), Wherein x and y are independently integers in the range of from 2 to 6, and wherein each M independently represents H or an alkali metal. A humidity sensor including the humidity sensor element is also disclosed.

Claims

1. A humidity sensor element comprising:

a dielectric substrate;

a nonporous conductive electrode having a first conductive member electrically coupled thereto, wherein the nonporous conductive electrode is disposed on the dielectric substrate;

a permeable conductive electrode having a second conductive member electrically coupled thereto, wherein the permeable conductive electrode has a thickness in a range of from 4 to 10 nanometers, and wherein the permeable conductive electrode is permeable by water vapor;

a detection layer disposed between the nonporous conductive electrode and the permeable conductive electrode, wherein the detection layer comprises a sulfonated copolymer including monomeric units comprising

2. The humidity sensor element of claim 1, wherein the dielectric substrate is nonporous.

3. The humidity sensor element of claim 1, wherein the dielectric substrate comprises a glass plate.

4. The humidity sensor element of claim 1, wherein the permeable conductive electrode comprises gold.

5. The humidity sensor element of claim 1, wherein the nonporous conductive electrode comprises gold.

6. The humidity sensor element of claim 1, wherein the sulfonated copolymer is a random copolymer including a segment represented by the stoichiometric formula

7. The humidity sensor element of claim 1, wherein the sulfonated copolymer has a sulfonate equivalent weight in a range of from 660 to 2000 grams per sulfonate equivalent.

8. A humidity sensor comprising:

a sensor chamber having an inlet opening;

a humidity sensor element according to claim 1 and having a capacitance, wherein the humidity sensor element is disposed within the sensor chamber in fluid communication with the inlet opening; and

an operating circuit in electrical communication with the first and second conductive leads of the humidity sensor element, whereby if the humidity sensor element is connected to a source of electrical power, the operating circuit measures the capacitance of the sensor element.

9. The humidity sensor of claim 8, wherein the sensor chamber further comprises an outlet opening in fluid communication with the inlet opening.

10. The humidity sensor of claim 8, further comprising a display device communicatively coupled with the operating circuit.