Flexible diagnostic patches for structural health monitoring

• US 20070261493A1
• Filed: 07/18/2007
• Published: 11/15/2007
• Est. Priority Date: 09/22/2003
• Status: Active Grant

• Current Assignee: Hyeung-Yun Kim
• Original Assignee: Hyeung-Yun Kim
• Inventors: Kim, Hyeung-Yun
• Granted Patent: US 7,536,912 B2
• Time in Patent Office: Days
• US Class Current: 73/594
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

Devices for monitoring structural health conditions of structures. A device includes a bottom substrate layer and an electrical connection layer disposed on the bottom substrate layer. The electrical connection layer includes a middle layer and a pair of generally comb-shaped electrodes disposed beneath the bottom surface of the middle layer. The device also includes one or more piezo-ceramic transducers sandwiched between the bottom substrate layer and the electrical connection layer, wherein the transducers are electrically coupled to the comb-shaped electrodes. The device also includes a top cover layer disposed on the electrical connection layer and means for communicating electrical signals to the piezo-ceramic transducers.

Claims

1. A device for monitoring structural health conditions of an object, comprising:

a bottom substrate layer;

an electrical connection layer disposed on said bottom substrate layer and including a middle layer, a pair of generally comb-shaped electrodes disposed beneath a bottom surface of the middle layer;

one or more piezo-ceramic transducers sandwiched between said bottom substrate layer and said electrical connection layer and electrically coupled to said comb-shaped electrodes;

a top cover layer disposed on said electrical connection layer; and

means for communicating electrical signals to said piezo-ceramic transducers.

2. The device of claim 1, wherein each said piezo-ceramic transducer is able to operate as at least one of a transmitter patch for generating a wave and a sensor patch for generating electrical signal in response to the wave.

3. The device of claim 1, wherein each said piezo-ceramic transducer includes a piezo-electric ceramic and first and second conductive flakes disposed on a top surface of said ceramic and electrically coupled to said pair of comb-shaped electrodes, said first flake extending to a bottom surface of said ceramic.

4. The device of claim 1, wherein each said piezo-ceramic transducer has a thickness of less than 0.1 inch.

5. The device of claim 1, further comprising:

one or more filler blocks disposed between said piezo-ceramic transducers.

6. The device of claim 1, wherein said top cover layer, electrical connection layer, and bottom substrate layer have a shape selected from the group consisting of a rectangle, oval, and circle.

7. The device of claim 6, wherein each said piezo-electric transducer has a shape of a generally elongated rectangular cylinder.

8. The device of claim 1, wherein said top cover layer, electrical connection layer, and bottom substrate layer have a fan-shape.

9. The device of claim 8, wherein each said piezo-electric transducer has a generally wedge shape.

10. The device of claim 1, wherein said electrical connection layer includes:

a pair of electrical connectors disposed on an upper surface of said middle layer and coupled to said means for communicating; and

a pair of vias for electrically connecting said pair of electrical connectors to said pair of comb-shaped electrodes.

11. The deice of claim 1, wherein said means for communicating includes a pair of electrical wires.

12. The device of claim 1, wherein said top cover layer and bottom substrate layer are formed of dielectric material.

13. The device of claim 1, wherein said middle layer is formed of electrically insulating material.

14. The device of claim 1, wherein said pair of comb-shaped electrodes include patterned thin metal coatings.

15. The device of claim 1, wherein said piezo-ceramic transducers are secured to the bottom substrate by thermo-setting adhesive.

16. A device for monitoring structural health conditions of an object, comprising:

a bottom substrate layer;

an electrical connection layer disposed on said bottom substrate layer and including a middle layer, a pair of electrode arrays disposed beneath a bottom surface of said middle layer;

one or more piezo-ceramic transducers sandwiched between said bottom substrate layer and said electrical connection layer and electrically coupled to said pair of electrode arrays;

a top cover layer disposed on said electrical connection layer; and

means for communicating electrical signals to said piezo-ceramic transducers.

17. The device of claim 16, wherein each said piezo-ceramic transducer includes a piezo-electric ceramic and first and second conductive flakes disposed on a top surface of said ceramic and electrically coupled to said pair of comb-shaped electrodes, said first flake extending to a bottom surface of said ceramic.

18. The device of claim 16, wherein each said piezo-ceramic transducer has a thickness of less than 0.1 inch.

19. The device of claim 16, wherein each said piezo-electric transducer has a shape of a generally elongated rectangular cylinder.

20. The device of claim 16, wherein said means for communicating includes a pair of electrical wires and wherein said electrical connection layer includes:

two sets of electrical wires disposed on an upper surface of said middle layer, each of said sets of wires being coupled to one of said pair of electrical wires; and

a plurality of vias for electrically connecting said two sets of electrical wires to said arrays of electrode arrays.

21. The device of claim 16, wherein said top cover layer and bottom substrate layer are formed of dielectric material.

22. The device of claim 16, wherein said middle layer is formed of electrically insulating material.

23. The device of claim 16, wherein said comb-shaped electrodes include patterned thin metal coatings.

24. The device of claim 16, wherein said piezo-ceramic transducers are secured to the bottom substrate by thermo-setting adhesive.