Fluid current energy capture apparatus and method

• US 8,884,496 B2
• Filed: 05/25/2011
• Issued: 11/11/2014
• Est. Priority Date: 05/25/2010
• Status: Active Grant

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: Lipson, Hod, Li, Shuguang
• Primary Examiner(s): Rosenau, Derek
• Assistant Examiner(s): GORDON, BRYAN P
• Application Number:
  US13/115,547
• Publication Number:
  US 20110291527A1
• Time in Patent Office: 1,266 Days
• Field of Search: 310/330, 310/339
• US Class Current: 310/339
• CPC Class Codes: H02N 2/185 using fluid streams
• CPC Class Codes: Y02B 10/30 Wind power

Abstract

One aspect of the present invention involves investigation of the principles and feasibility of the harvesting energy from the wind in constrained spaces, such as around buildings, as an alternative to conventional rotary wind turbines. Some embodiments involve the idea of harvesting energy from wind induced vibration instead of wind driven rotation. Some embodiments are a tree-like generator for wind energy harvesting including multiple vibrating elements. Some embodiments include a “piezo stalk and leaf” as an element of a plant-like generator. In some embodiments, a leaf, made at least in part from piezoelectric type materials is capable of generating electrical power through wind induced vibrations. Some embodiments include a cantilever piezo-electric material containing stalk member that exhibits at least one mode of cantilever motion. Some embodiments include an elongated piezoelectric material containing stalk member (which may or may not qualify as a cantilever), where a pendular member (or leaf member) is mechanically connected to the stalk and extends in a direction substantially non-parallel (for example, perpendicular to) the direction of elongation of the stalk.

Claims

1. A device comprising:

a frame;

an elongated stalk member defining a direction of elongation, a first end and second end;

a pendular member; and

a set of electrical terminal(s)

wherein;

the stalk member comprises a frame connection portion that is at least substantially fixedly mechanically connected to the frame;

the stalk member includes a piezoelectric type material portion;

the stalk member is sized, shaped, connected, structured, located and/or has an appropriate degree of rigidity so that it will exhibit at least a first mode of cantilever motion when the device is placed in a fluid stream with the fluid stream having a first direction and the stalk member having a first orientation with respect to the fluid stream;

the piezoelectric type material portion is located so that the first mode of cantilever motion of the stalk will be transduced by the piezoelectric type material portion into transduced electrical energy;

the set of electrical terminal(s) is electrically connected to the stalk so that the transduced electrical energy is communicated to the first set of electrical terminals; and

the pendular member is mechanically connected directly to the stalk member in the vicinity of its second end and extends from the stalk member in a direction that is at least substantially parallel to the direction of elongation.

2. The device of claim 1 wherein the stalk member is generally flat and generally planar in shape.

3. The device of claim 2 wherein:

the stalk member is elongated, which elongation defines a first end and a second end; and

the frame connection portion is located at the first end.

4. The device of claim 3 wherein the stalk member is generally rectangular in shape.

5. The device of claim 2 wherein the piezoelectric portion of the stalk includes a first piezoelectric layer and a second piezoelectric layer.

6. The device of claim 5 wherein the first piezoelectric layer and the second piezoelectric layer are mechanically connected to each other by adhesive.

7. The device of claim 5 wherein the stalk includes an intermediate layer between the first piezoelectric layer and the second piezoelectric layer.

8. The device of claim 7 wherein the intermediate layer does not fill substantially an entirety of a space between the first piezoelectric layer and the second piezoelectric layer.

9. The device of claim 1 wherein the frame is structured, located and/or oriented so that the first orientation between the stalk-extension direction and an expected ambient fluid streams is at least generally perpendicular.

10. The device of claim 1 wherein the stalk member further is sized, shaped, connected, structured, located and/or has an appropriate degree of rigidity so that it will exhibit a second mode of cantilever motion when the device is placed in a fluid stream at the first orientation.

11. The device of claim 10 wherein:

the first mode of cantilever motion is a bending mode; and

the second mode of cantilever motion is a twisting mode.

12. A device comprising:

a frame;

an elongated stalk member defining a direction of elongation, a first end and second end;

a pendular member;

a set of electrical terminal(s); and

a hinge,

wherein;

the pendular member is mechanically connected to the stalk member by the hinge;

the stalk member comprises a frame connection portion that is at least substantially fixedly mechanically connected to the frame at its first end so that it extends away from its fixed connection to the frame in a stalk-extension direction that is at least approximately parallel to the direction of elongation;

the stalk member includes a piezoelectric type material portion;

the stalk member is sized, shaped, connected, structured and/or located so that it will exhibit a fluttering motion when the device is placed in a fluid stream with the fluid stream having a first direction and the stalk member having a first orientation with respect to the fluid stream;

the stalk member includes a first lateral edge that is at least generally parallel to the direction of elongation;

the piezoelectric type material portion is located so that the fluttering motion of the stalk member will be transduced into transduced electrical energy;

the set of electrical terminal(s) is electrically connected to the stalk so that the transduced electrical energy is communicated to the first set of electrical terminals; and

the pendular member is mechanically connected to the stalk member at the first lateral edge in the vicinity of its second end and extends from the stalk member in a direction that is at least substantially non-parallel to the direction of elongation.

13. The device of claim 12 wherein the stalk member is generally flat and generally planar in shape.

14. The device of claim 12 wherein the frame is structured, located and/or oriented so that the first orientation between the stalk-extension direction and an expected ambient fluid streams is at least generally perpendicular.

15. The device of claim 12 wherein the stalk member is sized, shaped, connected, structured;

located and/or has an appropriate degree of rigidity so that it will exhibit at least a first mode of cantilever motion when the device is placed in a fluid stream with the fluid stream at the first orientation.

16. The device of claim 12 wherein the pendular member is mechanically connected to the stalk member in the vicinity of its second end and extends from the stalk member in a direction that is at least approximately perpendicular to the direction of elongation.

17. The device of claim 12 wherein the pendular member is generally flat, generally planar and has one of the following shapes:

round, square or equilateral triangle.

18. A device comprising:

a frame;

an elongated stalk member;

a pendular member;

a hinge defining at least a first axis or rotation;

and

a set of electrical terminal(s)

wherein;

the stalk member comprises a frame connection portion that is at least substantially fixedly mechanically connected to the frame;

the stalk member includes a piezoelectric type material portion;

the stalk member is sized, shaped, connected, structured and/or located so that it will exhibit a fluttering motion when the device is placed in a fluid stream with the fluid stream having a first direction and the stalk member having a first orientation with respect to the fluid stream;

the piezoelectric type material portion is located so that the fluttering motion of the stalk member will be transduced into transduced electrical energy;

the set of electrical terminal(s) is electrically connected to the stalk so that the transduced electrical energy is communicated to the first set of electrical terminals; and

the pendular member is rotatably mechanically connected to the stalk member by the hinge so that the pendular member may rotate with respect to the stalk member about at least the first axis of rotation.