ENERGY HARVESTING FROM CONSTRAINED BUCKLING OF PIEZOELECTRIC BEAMS

• US 20170047865A1
• Filed: 08/11/2016
• Published: 02/16/2017
• Est. Priority Date: 08/13/2015
• Status: Active Grant

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York), Board of Regents of the University of Michigan (University of Michigan)
• Inventors: KARAMI, Mohammad Amin, ANSARI, Mohammad Hossein, INMAN, Daniel J.
• Granted Patent: US 10,447,177 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/304 Beam type

Abstract

An energy harvesting system for harvesting energy in response to application of an external force. The energy harvesting system comprises a beam member having a central member and at least one piezoelectric layer joined to the central member for deflection therewith. The beam member includes opposing first and second ends and is elastically deformable in response to application of the external force. A first mount couples the first end of the beam member and is generally stationary. A second mount couples the second end of the beam member. The second mount and the second end of the beam member are generally moveable in response to application of the external force between a first position and a second position, thereby outputting energy from the at least one piezoelectric layer in response to the movement from the first position to the second position.

Claims

1. An energy harvesting system for harvesting energy in response to application of an external force, said energy harvesting system comprising:

a first beam member having a central member and at least one piezoelectric layer joined to the central member for deflection therewith, said first beam member having opposing first and second ends, said first beam member being elastically deformable in response to application of the external force;

a first mount coupling said first end of said first beam member, said first mount being generally stationary;

a second mount coupling said second end of said first beam member, said second mount and said second end of said first beam member being generally moveable in response to application of the external force between a first position and a second position, thereby outputting energy from said at least one piezoelectric layer in response to said movement from said first position to said second position; and

a stop member physically opposing movement of said second mount and said second end of said first beam member in said second position.

2. The energy harvesting system according to claim 1 wherein said first beam member comprises two piezoelectric layers disposed on opposing sides of said central member.

3. The energy harvesting system according to claim 1 wherein said second mount is positioned generally vertically relative to said first mount.

4. The energy harvesting system according to claim 1 wherein said second mount is positioned generally horizontally relative to said first mount.

5. The energy harvesting system according to claim 1, further comprising a second beam member having a central member and at least one piezoelectric layer joined to the central member for deflection therewith, said second beam member having opposing first and second ends, said second beam member being elastically deformable in response to application of the external force.

6. The energy harvesting system according to claim 5 wherein said first end of said second beam member being coupled to said first mount, said second end of said second beam member being coupled to said second mount.

7. The energy harvesting system according to claim 6 wherein said second beam member is parallel to said first beam member.

8. The energy harvesting system according to claim 1 wherein the first mount comprises a lower beam and the second mount comprises an upper beam, further comprising:

a plurality of oblique beams, a first pair of the plurality of oblique beams interconnecting the first mount to the first beam member and a second pair of the plurality of oblique beams interconnecting the second mount to the first beam member, the plurality of oblique beams transmitting a compressive bending force to the first beam member in response to the external force.

9. The energy harvesting system according to claim 8 wherein the stop member comprises a block member disposed between the lower beam and the upper beam to oppose the external force once the upper beam is spaced a predetermined distance from the lower beam.

10. The energy harvesting system according to claim 1 wherein the at least one piezoelectric layer comprises at least two piezoelectric layers, each of the at least two piezoelectric layers being joined to opposing sides of the central member.

11. The energy harvesting system according to claim 1 wherein the at least one piezoelectric layer is joined to only a portion of a length of the central member.

12. The energy harvesting system according to claim 11 wherein the at least one piezoelectric layer is joined to a central portion of the length of the central member.

13. The energy harvesting system according to claim 1 wherein the central member is made of a spring steel material.

20. The energy harvesting system according to claim 11 wherein the at least one piezoelectric layer is joined to a central portion of the length of the central member.

14. An energy harvesting system for harvesting energy in response to application of an external force, said energy harvesting system comprising:

an upper beam member;

a lower beam member being moveable relative to the upper beam member in response to application of the external force;

a middle beam member having a central member and at least one piezoelectric layer joined to the central member for deflection therewith, said middle beam member having opposing first and second ends, said middle beam member being elastically deformable in response to application of the external force;

a first pair of oblique beams interconnecting the upper beam member to the first and second ends of the middle beam member;

a second pair of oblique beams interconnecting the lower beam member to the first and second ends of the middle beam member;

wherein application of the external force causes application of a compressive force on the middle beam member thereby outputting electrical energy from the at least one piezoelectric layer.

15. The energy harvesting system according to claim 14, further comprising:

a stop member physically opposing movement of said upper beam member relative to said lower beam member beyond a predetermined distance.

16. The energy harvesting system according to claim 14 wherein said middle beam member comprises two piezoelectric layers disposed on opposing sides of said central member.

17. The energy harvesting system according to claim 14 wherein said middle beam member comprises a pair of central members each having at least one piezoelectric layers joined thereto.

18. The energy harvesting system according to claim 14 wherein the at least one piezoelectric layer comprises at least two piezoelectric layers, each of the at least two piezoelectric layers being joined to opposing sides of the central member.

19. The energy harvesting system according to claim 14 wherein the at least one piezoelectric layer is joined to only a portion of a length of the central member.