Integrated electronic device for monitoring humidity and/or corrosion

• US 10,001,453 B2
• Filed: 03/28/2014
• Issued: 06/19/2018
• Est. Priority Date: 03/29/2013
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Pagani, Alberto, Murari, Bruno
• Primary Examiner(s): Reisner, Noam
• Application Number:
  US14/781,104
• Publication Number:
  US 20160041113A1
• Time in Patent Office: 1,544 Days
• CPC Class Codes: G01N 17/04 Corrosion probes
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825

Abstract

An integrated electronic device 1 for detecting at least one parameter related to humidity and/or presence of water and/or acidity/basicity of an environment surrounding the device is described. Such device 1 comprises a separation layer 14 from the surrounding environment, comprising at least one portion of insulating material 14, and further comprises a first conductive member 11 and a second conductive member 12, made of an electrically conductive material, arranged inside the separation layer 14, with respect to the surrounding environment, and separated from the surrounding environment by the separation layer 14. The device 1 also comprises a measurement module 15, having two measurement terminals 151, 152, electrically connected with the first 11 and the second 12 conductive members, respectively; the measurement module 15 is configured to provide an electric potential difference between the first 11 and the second 12 conductive members. The device 1 further comprises electrode means 13, configured to act as an electrode, arranged outside of the separation layer 14, with respect to the first 11 and the second 12 conductive members; the electrode means 13 are arranged so as to form, with the first 11 and the second 12 conductive members, an electromagnetic circuit having an electromagnetic circuit overall impedance variable based upon the exposure to environmental conditions with a variable level of humidity and/or acidity/basicity. The measurement module 15 is configured to measure the electromagnetic circuit overall impedance, which is present between the measurement terminals 151, 152, and to determine the at least one parameter to be detected, based on the overall impedance measured.

Claims

1. An integrated electronic device for detecting changes in a parameter related to an environment surrounding the device, the device comprising:

first and second conductive members;

a measurement module comprising first and second measurement terminals respectively coupled to the first and the second conductive members, and configured to provide an electrical potential difference between the first and second conductive members;

a separation layer comprising an insulating material and configured to enclose the first and second conductive members and the measurement module so as to be separated from the surrounding environment; and

an electrode assembly on the separation layer and exposed to the surrounding environment and adjacent the first and the second conductive members, the electrode assembly forming with the first and second conductive members an electromagnetic circuit having an impedance that varies based upon exposure to the surrounding environment; and

wherein the measurement module is configured to measure the impedance between the first and second measurement terminals to detect changes in the environmental parameter based on changes of the measured impedance, wherein the impedance is a complex number, wherein the device determines that an increase in a level of humidity of the surrounding environment has occurred in response to a decrease in an imaginary part of the impedance, wherein the device determines that an increase in the presence of water within the surrounding environment has occurred in response to a decrease in a real part of the impedance, and wherein the device determines that corrosion of a metal structure present within the surrounding environment has occurred in response to an increase in the real part of the impedance.

2. The device according to claim 1, wherein the insulating material comprises a passivation and galvanic insulation material.

3. The device according to claim 1, wherein the electrode assembly comprises a third conductive member to form with the first conductive member a first capacitor having a first capacitance, and to form with the second conductive member a second capacitor having a second capacitance so that the electromagnetic circuit comprises the first capacitor, the third conductive member and the second capacitor coupled in series, with the third conductive member having an external impedance associated therewith, and with the impedance of the electromagnetic circuit being defined by the first capacitance, the external impedance, and the second capacitance.

4. The device according to claim 2, wherein the third conductive member comprises a plurality of stripes comprising an electrically conductive material arranged on the separation layer so as to form a stripe geometric pattern comprising the plurality of stripes and a plurality of interstitial spaces between the plurality of stripes;

wherein the stripe geometric pattern has a first portion overlapping the first conductive member and spaced apart therefrom by the separation layer; and

wherein the stripe geometric pattern has a second portion overlapping the second conductive member and spaced apart therefrom by the separation layer.

5. The device according to claim 1, wherein the environment surrounding the device is solid material that includes metal structures.

6. The device according to claim 5, wherein the electrode assembly comprises a third conductive member comprising a plurality of stripes comprising an electrically conductive material arranged on the separation layer so as to form a stripe geometric pattern comprising the plurality of stripes and a plurality of interstitial spaces between the plurality of stripes, with the interstitial spaces to be filled by the solid material.

7. The device according to claim 5, wherein the solid material comprises concrete and the metal structures comprise metal rods within the concrete.

8. The device according to claim 1, further comprising an absorbing material on the electrode assembly exposed to the surrounding environment, the absorbing material comprising a dielectric and polymeric absorbing material to absorb humidity and/or water from the surrounding environment.

9. The device according to claim 8, wherein the electrode assembly comprises a third conductive member comprising a plurality of stripes comprising an electrically conductive material arranged on the separation layer so as to form a stripe geometric pattern comprising the plurality of stripes and a plurality of interstitial spaces between the plurality of stripes, with the absorbing material contacting both the separation layer and the third conductive member so as to fill interstitial spaces.

10. The device according to claim 1, wherein the first and second conductive members comprise conductive segments arranged in a shape of a double comb.

11. The device according to claim 1, wherein the first and second conductive members are separated by an internal insulating material that is not exposed to the surrounding environment.

12. The device according to claim 1, wherein the measurement module is configured to generate an alternating voltage with a preset frequency.

13. The device according to claim 1, wherein the measurement module comprises a processor configured to store initial calibration data, to perform measurements, to store the measurements, and to correlate differences between the stored initial calibration data and the measurements with changes in the environmental parameter.

16. The device according to claim 1, wherein changes in the impedance of the electromagnetic circuit result from changes in the electrode assembly caused by exposure to the surrounding environment.

14. A method for detecting changes in a parameter related to a surrounding environment, the method comprising:

providing a device comprising;

a measurement module comprising first and second measurement terminals respectively coupled to first and second conductive members respectively, and configured to provide an electrical potential difference between the first and second conductive members;

a separation layer comprising an insulating material and configured to enclose the first and second conductive members and the measurement module so as to be separated from the surrounding environment; and

an electrode assembly over the separation layer and exposed to the surrounding environment and adjacent the first and the second conductive members, the electrode assembly forming with the first and second conductive members an electromagnetic circuit having an impedance that varies based upon changes in the electrode assembly caused by exposure to the surrounding environment;

operating the device so that the measurement module measures a reference impedance between the first and second measurement terminals;

positioning the device within the surrounding environment;

operating the device so that the measurement module measures an overall impedance between the first and second measurement terminals; and

correlating deviation of the measured overall impedance from the measured reference impedance with changes in the environmental parameter, wherein the overall impedance is a complex number, and wherein correlating deviation of the measured overall impedance comprises;

determining that an increase in a level of humidity of the surrounding environment has occurred in response to a decrease in an imaginary part of the overall impedance;

determining that an increase in the presence of water within the surrounding environment has occurred in response to a decrease in a real part of the overall impedance; and

determining that corrosion of a metal structure present within the surrounding environment has occurred in response to an increase in the real part of the overall impedance.

15. The method according to claim 14, wherein the electrode assembly comprises a third conductive member to form with the first conductive member a first capacitor having a first capacitance, and to form with the second conductive member a second capacitor having a second capacitance so that the electromagnetic circuit comprises the first capacitor, the third conductive member and the second capacitor coupled in series, wherein the third conductive member has an external impedance associated therewith, and wherein the overall impedance of the electromagnetic circuit is defined by the first capacitance, the external impedance, and the second capacitance.