Moisture sensor, diaper with such a sensor, and method for detecting the presence and/or the intactness of the moisture sensor

• US 20040095247A1
• Filed: 06/20/2003
• Published: 05/20/2004
• Est. Priority Date: 08/15/2000
• Status: Abandoned Application

• Current Assignee: Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek
• Original Assignee: Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek
• Inventors: Van Heck, Gerardus Titus, De Haan, Peter Hillebrand
• Application Number:
  US10/344,817
• Publication Number:
  US 20040095247A1
• Time in Patent Office: Days
• US Class Current: 340/573.5
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 2013/424 having an electronic device
• CPC Class Codes: G01N 27/225 by using hygroscopic materials

Abstract

The moisture sensor for detecting moisture comprises at least one first electrode provided with at least one IGP, at least one second electrode and a dielectric included between the first and the second electrode. The dielectric is of a type that can absorb moisture, so that the presence of moisture can be detected on the basis of an electric voltage difference between the first and the second electrode. The first electrode is provided with a ribbon-shaped carrier, to which the at least one IGP is applied.

Claims

1. A moisture sensor for detecting moisture, comprising at least one first electrode provided with an IGP, at least one second electrode and at least one dielectric included between the first and the second electrode, which dielectric is of a type that can absorb moisture, so that the presence of moisture can be detected on the basis of an electric voltage difference between the first and the second electrode, characterized in that the first electrode is provided with a ribbon-shaped carrier, to which the at least one IGP is applied.

2. A moisture sensor according to claim 1, characterized in that the ribbon-shaped carrier of the first electrode is provided with a thread, to which the at least one IGP is applied or a ribbon-shaped fabric, to which the at least one IGP is applied.

3. A moisture sensor according to claim 2, characterized in that the thread or the ribbon-shaped fabric of the first electrode comprises polyester.

4. A moisture sensor according to any one of the preceding claims, characterized in that the thread or the ribbon-shaped fabric of the first electrode is coated with the at least one IGP.

5. A moisture sensor according to any one of the preceding claims, characterized in that the at least one IGP comprises polypyrrole.

6. A moisture sensor according to any one of the preceding claims, characterized in that the second electrode has an elongated form, while the second electrode extends parallel to the first electrode.

7. A moisture sensor according to claim 6, characterized in that the second electrode is provided with a ribbon-shaped carrier, to which a current-conducting material is applied.

8. A moisture sensor according to any one of the preceding claims, characterized in that the moisture sensor is, at least substantially, of ribbon-shaped design.

9. A moisture sensor according to any one of the preceding claims, characterized in that the dielectric comprises a fabric.

10. A moisture sensor according to claim 9, characterized in that the fabric of the dielectric comprises cotton.

11. A moisture sensor according to claim 10, characterized in that the dielectric is treated with an acid buffer solution.

12. A moisture sensor according to any one of claims 9-11, characterized in that the fabric of the dielectric is wound around the first electrode.

13. A moisture sensor according to claim 12, characterized in that a moisture-proof coating is locally applied to an exterior of the fabric of the dielectric for designing the moisture sensor so as to be sensitive to moisture in dependence on the place thereof.

14. A moisture sensor according to any one of the preceding claims 9-13, characterized in that the second electrode is applied to the fabric of the dielectric.

15. A moisture sensor according to claims 8, 12 and 14, characterized in that the second electrode extends in a longitudinal direction of the moisture sensor.

16. A moisture sensor according to claim 15, characterized in that the second electrode is arranged at an edge of the fabric of the dielectric located on an exterior of the moisture sensor.

17. A moisture sensor according to any one of the preceding claims, characterized in that the second electrode comprises a material different from the first electrode.

18. A moisture sensor according to claim 17, characterized in that the second electrode is provided with graphite.

19. A moisture sensor according to any one of the preceding claims, characterized in that the second electrode is provided with at least one IGP different from the at least one IGP of the first electrode.

20. A diaper provided with a moisture sensor according to any one of the preceding claims.

21. A diaper provided with a moisture sensor according to any one of the preceding claims 1-5, characterized in that the first electrode extends around an area of the diaper where the presence of moisture should be detected, while the second electrode is arranged on at least part of the fluff of the diaper in the area or on the coating foil of the diaper in the area, so that the fluff of the area functions as the dielectric.

22. A diaper according to claim 21, characterized in that the second electrode comprises graphite.

23. A diaper according to claim 22, characterized in that the graphite is applied to the fluff in the form of a colloidal suspension.

24. A diaper according to claim 21, characterized in that the second electrode is provided with at least one IGP.

25. A method for detecting the presence and/or the intactness of a moisture sensor according to any one of claims 1-19, in which the resistance of the two electrodes individually, the direct-current resistance between the electrodes and/or the alternating-current resistance between the electrodes and/or the current through a predetermined resistance included between the first and the second electrode is measured.

26. A method for determining, by means of the moisture sensor according to any one of the preceding claims 1-19, the amount of moisture and/or determining the sum of the lengths of parts of the first electrode of the moisture sensor that are moist, by measuring the internal resistance between the first and the second electrode, in particular by measuring a short-circuit current between the first and the second electrode.

27. A method for determining, by means of a moisture sensor according to any one of the preceding claims 1-19, the place of the moisture on the sensor, by determining the ratio between the short-circuit currents measured respectively at two ends of the sensor between the first and the second electrode.