Energy harvesting technique to support remote wireless MEMS RF sensors

• US 7,514,804 B2
• Filed: 10/17/2006
• Issued: 04/07/2009
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Wang, Sheng T.
• Primary Examiner(s): Ponomarenko; Nicholas
• Application Number:
  US11/550,108
• Publication Number:
  US 20080204005A1
• Time in Patent Office: 903 Days
• Field of Search: 290/1.R, 290/1.A, 290/6, 290/45, 324/249, 324/244, 310/26, 310/328
• US Class Current: 290/1.00R
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: H02K 35/02 with moving magnets and stationary coil systems
• CPC Class Codes: H02N 2/186 Vibration harvesters

Abstract

A method of harvesting vibrational energy is provided. This method involves generating a high magnetic flux density field within a current induction conductor such as an induction coil. The high magnetic flux density field is generated between two same pole magnets. The high magnetic flux density field may be displaced relative to the current induction conductor with vibrational energy. These displacements then cause the current induction conductor to be energized. The two same pole magnets are mounted between piezoelectric transducer (PZT) materials. These PZT materials generate an electric potential when the PZT materials are subject to the mechanical stresses of the vibrational energy. The electrical energy translated from the vibrational energy through both the energized current induction conductor and stress PZT materials may then be used to power a power circuitry or be stored for later use.

Claims

1. A method of harvesting vibrational energy comprising:

generating a high magnetic flux density field within a current induction conductor, wherein the high magnetic flux density field is generated between two same pole magnets;

displacing the high magnetic flux density field relative to the current induction conductor with vibrational energy;

energizing the current induction conductor with displacements of the high magnetic flux density field relative to the current induction conductor;

mechanically mounting the two same pole magnets between piezoelectric transducer (PZT) materials;

generating a electrical potential across the PZT materials when the PZT materials are subject to the vibrational energy; and

storing electrical energy translated from the vibrational energy through both the energized current induction conductor and mechanically stressed PZT materials.

2. The method of claim 1, further comprising powering a Micro Electro-Mechanical Systems (MEMS) device from the stored electrical energy.

3. The method of claim 1, wherein the MEMS device comprises a sensor.

4. The method of claim 1, wherein the MEMS device comprises a radio frequency (RF) identifier (ID) tag.

5. The method of claim 1, wherein the MEMS device is embedded within a manufactured object.

6. The method of claim 5, wherein the MEMS device comprises:

an radio frequency (RF) identifier (ID) tag; and

a micro-mechanical transducer operable to monitor environmental conditions at the object; and

a wireless transmitter operable to transmit data on the environmental conditions at the object.

7. The method of claim 6, wherein environmental conditions at the object comprise at least one of a group of characteristics consisting of temperature, pressure, vibrations, sound, and acceleration acting on the MEMS device.

8. A Micro Electro-Mechanical Systems (MEMS) device, comprising:

a first harvesting system operable to store vibrational energy as electrical energy, the first harvesting system comprising;

a high magnetic flux density field generated within a current induction conductor, wherein the high magnetic flux density field is generated between two same pole magnets;

a mechanical mount wherein vibrational energy displaces the high magnetic flux density field relative to the current induction conductor to energize the current induction conductor;

a second harvesting system operable to store vibrational energy as electrical energy, the second harvesting system comprising;

piezoelectric transducer (PZT) materials operable to generate a electrical potential across the PZT materials when the PZT materials are mechanically stressed by the vibrational energy, wherein the mechanical mount is made from the PZT materials; and

a storage device coupled to the current induction conductor and PZT materials wherein the storage device is operable to store electrical energy from the energized current induction conductor and the stressed PZT materials.

9. The MEMS device of claim 8, wherein the MEMS device is powered from the stored electrical energy.

10. The MEMS device of claim 8, wherein the MEMS device comprises a sensor.

11. The MEMS device of claim 8, wherein the MEMS device comprises a radio frequency (RF) identifier (ID) tag.

12. The MEMS device of claim 8, wherein the MEMS device is embedded within a manufactured object.

13. The MEMS device of claim 8, wherein the MEMS device further comprises:

an radio frequency (RF) identifier (ID) tag; and

a micro-mechanical transducer operable to monitor environmental conditions at the object; and

a wireless transmitter operable to transmit data on the environmental conditions at the object.

14. The MEMS device of claim 13, wherein environmental conditions at the object comprise at least one of a group of characteristics consisting of temperature, pressure, vibrations, sound, and acceleration acting on the MEMS device.

15. A power harvesting device operable to translate vibrational energy into electrical energy, the power harvesting device comprising:

a first harvesting system operable to store vibrational energy as electrical energy, the first harvesting system comprising;

a high magnetic flux density field generated within a current induction conductor, wherein the high magnetic flux density field is generated between two same pole magnets;

a mechanical mount wherein vibrational energy displaces the high magnetic flux density field relative to the current induction conductor to energize the current induction conductor; and

a second harvesting system operable to store vibrational energy as electrical energy, the second harvesting system comprising;

piezoelectric transducer (PZT) materials operable to generate a electrical potential across the PZT materials when the PZT materials are mechanically stressed by the vibrational energy, wherein the mechanical mount is made from the PZT materials; and

circuitry energized by the energized current induction conductor and mechanically stressed PZT materials.

16. The power harvesting device of claim 15, further comprising a storage device coupled to the current induction conductor and PZT materials wherein the storage device is operable to store electrical energy from the energized current induction conductor and the stressed PZT materials.

17. The power harvesting device of claim 15, wherein the power harvesting device powers a wireless sensor system.

18. The power harvesting device of claim 15, wherein the power harvesting device powers a radio frequency (RF) identifier (ID) tag.

19. The power harvesting device of claim 15, wherein the power harvesting device powers is embedded within a manufactured object.

20. The power harvesting device of claim 15, wherein the power harvesting device powers a MEMS device.

21. The power harvesting device of claim 20, wherein the MEMS device further comprises:

an radio frequency (RF) identifier (ID) tag; and

a micro-mechanical transducer operable to monitor environmental conditions at the object; and

a wireless transmitter operable to transmit data on the environmental conditions at the object.

22. The power harvesting device of claim 21, wherein environmental conditions at the object comprise at least one of a group of characteristics consisting of temperature, pressure, vibrations, sound, and acceleration acting on the MEMS device.

23. The power harvesting device of claim 15, wherein the mechanical mount comprises a tuning fork design.