Piezoelectric vibration energy harvesting device

• US 20050134149A1
• Filed: 01/11/2005
• Published: 06/23/2005
• Est. Priority Date: 07/11/2003
• Status: Abandoned Application

• Current Assignee: Meggitt (Maryland), Inc. (Amphenol Corporation)
• Original Assignee: Meggitt (Maryland), Inc. (Amphenol Corporation)
• Inventors: Deng, Ken Kan, Andic, Kikmet
• Application Number:
  US11/031,993
• Publication Number:
  US 20050134149A1
• Time in Patent Office: Days
• US Class Current: 310/339
• CPC Class Codes: H02N 2/181 Circuits; Control arrangements or methods
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors

Abstract

A piezoelectric vibration energy harvesting device which is made up of a first mass, a second, a first spring coupled to the first mass, and a second spring coupled to the second mass. A piezoelectric element is bonded between the first mass and the second spring, so that a stress applied to the second spring is applied to the piezoelectric element

Claims

1. A piezoelectric vibration energy harvesting device, comprising:

a base;

a mass; and

a cymbal stack disposed between the base and the proof mass, the cymbal stack comprising;

a piezoelectric element disposed between the base and the proof mass;

a first cymbal-shaped cap disposed between the mass and the piezoelectric crystal; and

a second cymbal-shaped cap disposed between the piezoelectric crystal and the base.

2. A device of claim 1, wherein

the piezoelectric element is a relaxor crystal.

3. A device of claim 1, wherein

the first and second cymbal-shaped caps also function as electrodes and are connected to an electric output of the device.

4. A device of claim 1, wherein

the electrical output is connected to an inductor.

5. A device of claim 4, wherein

the piezoelectric element and the inductor have a resonance frequency which is tuned to be approximately equal to a mechanical resonance of the cymbal stack.

6. A device of claim 4, wherein

the inductor is a metal coil.

7. A device of claim 4, wherein

the inductor is a gyrator, said gyrator simulating an inductor coil by converting impedance into its inverse.

8. A piezoelectric vibration energy harvesting device, comprising:

a first mass;

a second mass;

a first spring element coupled to said first mass;

a second spring element coupled to said second mass; and

a piezoelectric element bonded between the first mass and the second spring,

whereby a stress applied to said second spring is applied to said piezoelectric element.

9. A device according to claim 8, wherein

said piezoelectric element is connected in parallel with an inductor.

10. A device according to claim 9, wherein

said inductor is a gyrator, said gyrator simulating an inductor coil by converting impedance into its inverse.

11. A device according to claim 8, wherein

said second spring element is a compression spring, and

said piezoelectric element being disposed on an end of said spring.

12. A device according to claim 8, wherein

said piezoelectric element is a ring disposed around a portion of said first mass and disposed inside of said second spring element.

13. A device according to claim 8, wherein

said second spring element includes a cantilever beam;

said piezoelectric element being disposed on said beam; and

said second mass being connected to an end of said beam.

14. A device according to claim 8, wherein

said second spring element includes first and second cymbal-shaped caps, and

said piezoelectric element being disposed between said first and second caps.