PIEZOELECTRIC GENERATOR

• US 20140217853A1
• Filed: 02/04/2013
• Published: 08/07/2014
• Est. Priority Date: 02/04/2013
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Mankowski, Peter
• Granted Patent: US 9,543,861 B2
• Time in Patent Office: Days
• US Class Current: 310/319
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors
• CPC Class Codes: H10N 30/60 having a coaxial cable structure
• CPC Class Codes: H10N 30/85 Piezoelectric or electrostrictive active materials
• CPC Class Codes: H10N 30/853 Ceramic compositions
• CPC Class Codes: H10N 30/8536 Alkaline earth metal based oxides, e.g. barium titanates
• CPC Class Codes: H10N 30/8554 Lead-zirconium titanate [PZT] based
• CPC Class Codes: H10N 30/875 Further connection or lead arrangements, e.g. flexible wiring boards, terminal pins

Abstract

The present disclosure provides an ionic ring comprising a number of piezoelectric elements, a piezoelectric device including the ionic ring, and a piezoelectric generator including the ionic ring and host devices incorporating the piezoelectric generator. The piezoelectric generator can be used to generate energy on a portable electronic device in response to mechanical deformation. The generated energy can be used instead of a battery of the portable electronic device or can be used to charge the battery.

Claims

1. A piezoelectric device, comprising:

a piezoelectric element having a number of dipoles, wherein the dipoles are arranged such that, in an unactuated state of the piezoelectric element, a zero dipole moment is formed by the dipoles of the piezoelectric element and, in an actuated state of the piezoelectric element caused by a force, a net dipole moment is formed by the dipoles of the piezoelectric element; and

a pair of electrodes located about the piezoelectric element to conduct a current created by the net dipole moment formed by the dipoles of the piezoelectric element.

2. The piezoelectric device of claim 1, wherein the pair of electrodes is located about the piezoelectric element to conduct the current created by the net dipole moment formed by the dipoles of the piezoelectric element when the piezoelectric element is in an actuated state.

3. The piezoelectric device of claim 1, wherein the dipoles in the piezoelectric element are asymmetrically arranged in the unactuated state such that the dipoles lack a center of symmetry.

4. The piezoelectric device of claim 1, wherein the piezoelectric element comprises an odd number of dipoles.

5. The piezoelectric device of claim 1, wherein the piezoelectric element has 3 or more dipoles.

6. The piezoelectric device of claim 1, wherein the piezoelectric element has 3, 5 or 7 dipoles.

7. The piezoelectric device of claim 1, wherein the piezoelectric element has 5 dipoles.

8. The piezoelectric device of claim 1, comprising a number of piezoelectric elements received within a dielectric substrate.

9. The piezoelectric device of claim 8, wherein the piezoelectric elements are arranged in an annular formation in the dielectric substrate and are equally spaced apart from each other in the annular formation to form an ionic ring.

10. The piezoelectric device of claim 9, comprising a plurality of ionic rings arranged in a stacked formation to form a piezoelectric cable.

11. The piezoelectric device of claim 10, wherein adjacent ionic rings differ in type, number and/or arrangement of the piezoelectric elements.

12. The piezoelectric device of claim 10, wherein the piezoelectric rings are arranged such that the piezoelectric elements of adjacent ionic rings are not aligned.

13. The piezoelectric device of claim 8, wherein the dielectric substrate elastically deforms in response to applied forces.

14. The piezoelectric device of claim 8, wherein each of the piezoelectric elements is individually connected to the electrodes.

15. The piezoelectric device of claim 8, wherein the piezoelectric elements are piezoelectric polycrystals.

16. A piezoelectric generator, comprising:

a piezoelectric device, comprising;

a piezoelectric element having a number of dipoles, wherein the dipoles are arranged such that, in an unactuated state of the piezoelectric element, a zero dipole moment is formed by the dipoles of the piezoelectric element and, in an actuated state of the piezoelectric element caused by a force, a net dipole moment is formed by the dipoles of the piezoelectric element; and

a pair of electrodes located about the piezoelectric element to conduct a current created by the net dipole moment formed by the dipoles of the piezoelectric element; and

an energy harvesting circuit connected to the piezoelectric device to capture and store electrical energy provided by the current.

17. The piezoelectric generator of claim 16, wherein the piezoelectric device is embedded in a housing of a portable electronic device.

18. The piezoelectric generator of claim 17, wherein piezoelectric elements arranged in an array or lattice formation throughout the case.

19. The piezoelectric generator of claim 18, wherein the piezoelectric device is embedded at or proximate to a key, a touchscreen, a buzzer or a speaker of the portable electronic device.

20. The piezoelectric generator of claim 17, wherein the piezoelectric device is a piezoelectric cable comprised of a plurality of ionic rings arranged in a stacked formation, wherein each ionic ring comprises a number of piezoelectric elements received within a dielectric substrate with the piezoelectric elements arranged in an annular formation in the dielectric substrate with the piezoelectric elements equally spaced apart from each other.

21. The piezoelectric generator of claim 20, wherein the piezoelectric cable is embedded in an article which can be carried or worn.

22. The piezoelectric generator of claim 20, wherein the piezoelectric cable is embedded in a data and/or power cable or cord.

23. An ionic ring, comprising:

a number of piezoelectric elements received within a dielectric substrate, wherein the piezoelectric elements are arranged in a ring-shape in a dielectric substrate and are equally spaced apart from each other in the ring-shaped arrangement, each piezoelectric element having a number of dipoles, wherein the dipoles are arranged such that, in an unactuated state of the piezoelectric element, a zero dipole moment is formed by the dipoles of the piezoelectric element and, in an actuated state of the piezoelectric element caused by a force, a net dipole moment is formed by the dipoles of the piezoelectric element.