Piezoelectric composite apparatus and related methods

• US 7,696,676 B2
• Filed: 12/18/2006
• Issued: 04/13/2010
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: General Electric Company, Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Gruber, Nanette Judith, Hays, David Cecil, Berkcan, Ertugrul, Kapusta, Christopher James, Delgado, Eladio Clemente, Andarawis, Emad Andarawis, Seeley, Charles Erklin, Sealing, Charles Scott, Wojnarowski, Robert John
• Primary Examiner(s): SAN MARTIN, JAYDI A
• Application Number:
  US11/640,803
• Publication Number:
  US 20080143216A1
• Time in Patent Office: 1,212 Days
• Field of Search: 310363-366
• US Class Current: 310/364
• CPC Class Codes: G01M 5/00 Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings G01M9/00 takes precedence
• CPC Class Codes: G01N 2291/0231 Composite or layered materials
• CPC Class Codes: G01N 29/245 Ceramic probes, e.g. lead zirconate titanate [PZT] probes
• CPC Class Codes: G01N 29/2475 Embedded probes, i.e. probes incorporated in objects to be inspected
• CPC Class Codes: H10N 30/302 Sensors
• CPC Class Codes: H10N 30/87 Electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 39/00 Integrated devices, or assemblies of multiple devices, comprising at least one piezoelectric, electrostrictive or magnetostrictive element covered by groups H10N30/00 – H10N35/00

Abstract

A piezoelectric planar composite apparatus to provide health monitoring of a structure and associated methods are provided. The piezoelectric planar composite apparatus includes a piezoelectric electric material layer, multiple electrodes positioned in electrical contact with the piezoelectric material layer, and multiple sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the electrodes and positioned to form multiple complementary electrode patterns. Each of the complementary electrode patterns is positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns. The interconnect conductors can be distributed over several electrode interconnect conductor carrying layers to enhance formation of the different complementary electrode patterns.

Claims

1. A piezoelectric planar composite apparatus comprising:

a piezoelectric material layer;

a plurality of electrodes positioned in electrical contact with the piezoelectric material layer;

a plurality of sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the plurality of electrodes and positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns; and

a first electrode interconnect conductor carrying layer and a second electrode interconnect conductor carrying layer each carrying a different one of the plurality of sets of electrode interconnect conductors, the first electrode interconnect conductor carrying layer positioned between the piezoelectric material layer and the second electrode interconnect conductor carrying layer.

2. The apparatus as defined in claim 1, further comprising:

a third electrode interconnect conductor carrying layer; and

wherein the first electrode interconnect conductor carrying layer, the second electrode interconnect conductor carrying layer, and the third electrode interconnect conductor carrying layer each carrying a different one of the plurality of sets of electrode interconnect conductors, the second electrode interconnect conductor carrying layer positioned between the first electrode interconnect conductor carrying layer and the third electrode interconnect conductor carrying layer.

3. The apparatus as defined in claim 1, wherein the piezoelectric material layer includes a first and second side, the second side opposite the first side, and wherein the apparatus further comprises:

a third electrode interconnect conductor carrying layer; and

wherein the first electrode interconnect conductor carrying layer, the second electrode interconnect conductor carrying layer, and the third electrode interconnect conductor carrying layer each carrying a different one of the plurality of sets of electrode interconnect conductors, the third electrode interconnect conductor carrying layer positioned adjacent the first side of the piezoelectric material layer, the first and the second electrode interconnect conductor carrying layers positioned adjacent the second side of the piezoelectric material layer, and the first electrode interconnect conductor carrying layer positioned between the second side of the piezoelectric material layer and the second electrode interconnect conductor carrying layer.

4. The apparatus as defined in claim 1,

wherein the plurality of electrodes are positioned in the same plane to define a plurality of in-plane electrodes;

wherein the plurality of in-plane electrodes include a first set of in-plane electrodes and a second set of in-plane electrodes, the first set of in-plane electrodes positioned spaced apart from the second set of in-plane electrodes;

wherein the plurality of sets of electrode interconnected conductors include a first set of electrode interconnect conductors electrically connected to the first set of in-plane electrodes carried on the first electrode interconnect conductor carrying layer and a second set of electrode interconnect conductors electrically connected to the second set of in-plane electrodes carried on the first electrode interconnect conductor carrying layer;

wherein the first set of in-plane electrodes and the first set of electrode interconnect conductors form a first one of the plurality of complementary electrode patterns; and

wherein the second set of in-plane electrodes and the second set of electrode interconnect conductors form a second of the plurality of complementary electrode patterns.

5. The apparatus as defined in claim 1,

wherein the piezoelectric material layer when operatively positioned includes an axis of usable strain;

and

wherein the apparatus is configured so that when operably positioned each of the plurality of complementary electrode patterns are separately selectable by a user to allow the user to select the electrode pattern providing an electric field axis most closely matching the axis of usable strain.

6. The apparatus as defined in claim 5, wherein the axis of usable strain varies over time, and wherein the apparatus further comprises a switch positioned to allow user electrode pattern selection to correspondingly be varied over time.

7. The apparatus as defined in claim 1, wherein the apparatus is configured so that when operably positioned each of the plurality of complementary electrode patterns are separately selectable by a user to allow the user to align a major piezoelectric polling axis of the apparatus with a separate selected direction of strain.

8. A piezoelectric planar composite apparatus comprising:

a piezoelectric material layer;

a plurality of electrodes positioned in electrical contact with the piezoelectric material layer;

a plurality of sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the plurality of electrodes and positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns; and

an apparatus interconnected layer positioned to connect the apparatus with a carbon fiber structure or carbon epoxy, the interconnect layer comprising an addition-type polyimide resin to enable the piezoelectric planar composite apparatus to withstand a temperature of at least approximately 190°

C. for approximately six hours without failure during interlamination within a composite structure during formation thereof.

9. A piezoelectric planar composite apparatus comprising:

a plurality of piezoelectric materials layers;

a plurality of electrodes each positioned in electrical contact with at least one of the plurality of piezoelectric material layers;

a plurality of sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the plurality of electrodes and positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns; and

a plurality of electrode interconnect conductor carrying layers, the plurality of electrode interconnect conductor carrying layers and the plurality of piezoelectric material layers together forming a planar stack of a plurality of pairs of alternating electrode interconnect conductor carrying layers and piezoelectric material layers defining a sandwich forming a plurality of interlinked electrode patterns selectable to align a user selected one of the electric field axes with a separate selected direction of strain.

10. A piezoelectric planar composite apparatus comprising:

a piezoelectric composite material layer including a plurality of piezoelectric fibers and a plurality of strips of an interconnect material separately positioned to bond each one of the plurality of piezoelectric fibers to at least one of the other of the plurality of piezoelectric fibers to define a piezoelectric fiber matrix, the interconnect material including an addition-type polyimide resin to enable the piezoelectric planar composite apparatus to withstand a pressure of at least approximately 90 to 100 PSI at a temperature of at least approximately 190°

C. for approximately six hours without failure during interlamination within a composite structure during formation thereof;

a plurality of electrodes positioned in electrical contact with the piezoelectric material layer;

a plurality of sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the plurality of electrodes and positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns.

11. A piezoelectric planar composite apparatus comprising:

a piezoelectric material;

a first plurality of in-plane electrodes in electrical contact with the piezoelectric material;

a first electrode interconnect conductor carrying layer positioned adjacent the piezoelectric material and carrying a first set of electrode interconnect conductors positioned in electrical contact with the first plurality of electrodes;

a second plurality of in-plane electrodes in electrical contact with the piezoelectric material and positioned in the same plane as the first plurality of electrodes;

a second electrode interconnect conductor carrying layer positioned adjacent the piezoelectric material and carrying a second set of electrode interconnect conductors positioned in electrical contact with a second plurality of electrodes and positioned so that the first electrode interconnect conductor carrying layer is between the piezoelectric material and the second electrode interconnect conductor carrying layer;

a third plurality of in-plane electrodes in electrical contact with the piezoelectric material; and

a third electrode interconnect conductor carrying layer positioned adjacent the piezoelectric material and carrying a third set of electrode interconnect conductors positioned in electrical contact with the third plurality of electrodes, the first, second, and third sets of electrode interconnect conductors positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns.

12. The apparats as defined in claim 11, wherein the second electrode interconnect conductor carrying layer is further positioned so that the second electrode interconnect conductor carrying layer is between the first and the third electrode interconnect conductor carrying layers.

13. The apparatus as defined in claim 11,

wherein the piezoelectric material includes a first and a second side, the second side opposite the first side;

wherein the third electrode interconnect conductor carrying layer is positioned adjacent the first side of the piezoelectric material;

wherein the first and second electrode interconnect conductor carrying layers are positioned adjacent the second side of the piezoelectric material; and

wherein the first electrode interconnect conductor carrying layer is positioned between the second side of the piezoelectric material and the second electrode interconnect conductor carrying layer.

14. The apparatus as defined in claim 11,

wherein the piezoelectric material when operatively positioned includes an axis of usable strain;

and

wherein the apparatus is configured so that when operably positioned each of the plurality of complementary electrode patterns are separately selectable by a user to allow the user to select the respective complementary electrode pattern providing an electric field axis most closely matching the axis of usable strain.

15. The apparatus as defined in claim 14, wherein the axis of usable strain varies over time, and wherein the apparatus further comprises a switch positioned to allow the user electrode pattern selection to correspondingly be varied over time.

16. The apparatus as defined in claim 11, wherein the apparatus is configured so that when operably positioned, each of the plurality of complementary electrode patterns are separately selectable by a user to allow the user to align a major piezoelectric polling axis of the apparatus with a separate selected direction of strain.

17. The apparatus as defined in claim 11, wherein the piezoelectric material, each of the electrode interconnect conductor carrying layers, each set of electrode interconnect conductors, and the electrodes are layered on a single substrate.

18. The apparatus as defined in claim 11, further comprising:

an apparatus interconnect layer positioned to connect the apparatus with a carbon fiber structure or carbon epoxy, the interconnect layer comprising an addition-type polyimide resin to enable the piezoelectric planar composite apparatus to withstand a pressure of at least approximately 90 to 100 PSI at a temperature of at least approximately 190°

C. for approximately six hours without failure during interlamination within a composite structure during formation thereof.

19. A piezoelectric planar composite apparatus comprising:

a piezoelectric material layer;

a plurality of electrodes positioned in electrical contact with the piezoelectric material layer;

an electrode interconnect conductor carrying layer positioned adjacent the piezoelectric material and carrying a set of electrode interconnect conductors positioned in electrical contact with a subset of the plurality of electrodes;

an apparatus interconnect layer positioned to connect the apparatus with a carbon fiber structure or carbon epoxy, the interconnect layer comprising an addition-type polyimide resin to enable the piezoelectric planar composite apparatus to withstand a high pressure of at least approximately 90 PSI and temperature of at least approximately 160°

C. without failure during interlamination within a composite structure during formation thereof.

20. The apparatus as defined in claim 19, wherein the addition-type polyimide resin includes Bismaleimide;

and wherein the piezoelectric planar composite apparatus can withstand a pressure of at least approximately 100 PSI and a temperature of at least approximately 190°

C. for approximately six hours without failure during interlamination within the composite structure during formation thereof.

21. A piezoelectric planar composite apparatus comprising:

a piezoelectric material layer adapted to be positioned on a structure including an axis of usable strain;

a plurality of electrodes positioned in electrical contact with the piezoelectric material layer and positioned in the same plane to define a plurality of in-plane electrodes, the plurality of in-plane electrodes forming an N×

N electrode matrix; and

a plurality of sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the plurality of electrodes and positioned to form a plurality of complementary electrode patterns, each of the plurality of complementary electrode patterns positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns; and

the apparatus being configured so that when operably positioned each of the plurality of complementary electrode patterns are separately selectable by a user to allow the user to select the electrode pattern providing an electric field axis most closely matching the axis of usable strain to thereby enhance power harvesting from the environment by the apparatus.

22. The apparatus as defined in claim 21, wherein the axis of usable strain varies over time, the apparatus further comprising:

a switch positioned to allow user electrode pattern selection to correspondingly be varied over time.