Devices, systems, and methods for sensing moisture
View Patent ↗Various exemplary embodiments, devices, systems, and methods for sensing moisture are disclosed, including at least one moisture sensor that comprises an optical fiber, a long period grating formed in at least a portion of the optical fiber, and a layer of PEI bonded to the long period grating. One exemplary embodiment comprises a system for measuring humidity, the system comprising an optical fiber moisture sensor having a mono-layer of PEI covalently-bonded to an outer surface of said optical fiber, a processor coupled to said optical fiber moisture sensor, and a moisture indicator coupled to said processor.
1. A moisture sensor comprising:
an optical fiber;
a long period grating formed in at least a portion of said optical fiber; and
a layer of polyethylenimine (PEI) bonded to said long period grating.
2. A fiber optic moisture sensor having a covalently-bonded polyethylenimine (PEI) mono-layer.
3. An optical fiber moisture sensor having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber.
4. A mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of an optical fiber moisture sensor.
5. A moisture sensor comprising:
an optical fiber; and
a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber.
6. The moisture sensor of claim 5 , wherein a molecular weight of said polyethylenimine (PEI) is within a range of approximately 7500 to approximately 1,000,000.
7. The moisture sensor of claim 5 , wherein a molecular weight of said polyethylenimine (PEI) is above 7500.
8. The moisture sensor of claim 5 , wherein a molecular weight of said polyethylenimine (PEI) is less than 1,000,000.
9. A moisture sensor embedded in a building material, said moisture sensor comprising an optical fiber having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber.
10. A moisture sensor attached to a building material, said moisture sensor comprising an optical fiber having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber.
11. A moisture sensor associated with a structure, said moisture sensor comprising an optical fiber having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber.
12. The moisture sensor of claim 11 , wherein said structure is a building.
13. The moisture sensor of claim 11 , wherein said structure is a machine.
14. The moisture sensor of claim 11 , wherein said structure is an equipment.
15. The moisture sensor of claim 11 , wherein said structure is an aircraft.
16. The moisture sensor of claim 11 , wherein said structure is a ship.
17. The moisture sensor of claim 11 , wherein said structure is a vehicle.
18. The moisture sensor of claim 11 , wherein said structure is a military equipment.
19. The moisture sensor of claim 11 , wherein said structure is a storage vessel.
20. The moisture sensor of claim 11 , wherein said structure is a pipeline.
21. The moisture sensor of claim 11 , wherein said structure is a bridge.
22. The moisture sensor of claim 11 , wherein said structure is an electrical conduit.
23. A system for measuring humidity, comprising:
optical fiber moisture sensor having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber;
a processor coupled to said optical fiber moisture sensor; and
a moisture indicator coupled to said processor.
24. A system for predicting mold growth, comprising:
optical fiber moisture sensor having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber;
a processor coupled to said optical fiber moisture sensor; and
a mold growth indicator coupled to said processor.
25. A system for predicting corrosion, comprising:
optical fiber moisture sensor having a mono-layer of polyethylenimine (PEI) covalently-bonded to an outer surface of said optical fiber;
a processor coupled to said optical fiber moisture sensor; and
a corrosion indicator coupled to said processor.
26. A method for fabricating a moisture sensor, comprising:
forming a long period grating in a core of an optical fiber; and
covalently-bonding a mono-layer of polyethylenimine (PEI) to an outer surface of a cladding of the optical fiber.
27. The method of claim 26 , further comprising:
stripping a covering from the cladding in the vicinity of the long period grating.
28. The method of claim 26 , further comprising:
saturating the core with hydrogen.
29. The method of claim 26 , further comprising:
applying a mask to a portion of the core.
30. The method of claim 26 , further comprising:
exposing an unmasked portion of the core to a refraction index-changing source of light.
31. The method of claim 26 , further comprising:
exposing an unmasked portion the core to a source of ultraviolet light.
32. The method of claim 26 , further comprising:
imprinting the long period grating onto the core.
33. The method of claim 26 , further comprising:
forming the mono-layer of polyethylenimine (PEI).
34. The method of claim 26 , further comprising:
annealing the core to remove excess hydrogen.
35. The method of claim 26 , further comprising:
identifying a loss band of light transmitted past the long period grating.
36. The method of claim 26 , further comprising:
exposing the moisture sensor to a variation in ambient humidity.
37. The method of claim 26 , further comprising:
monitoring a loss band of light transmitted past the long period grating.
38. The method of claim 26 , further comprising:
quantifying a change in a loss band of light transmitted past the long period grating.
39. The method of claim 26 , further comprising:
correlating a change in a loss band of light transmitted past the long period grating with a moisture level.
40. The method of claim 26 , further comprising:
indicating a moisture level.