Micromachined, piezoelectric vibration-induced energy harvesting device and its fabrication

• US 20070284969A1
• Filed: 04/10/2006
• Published: 12/13/2007
• Est. Priority Date: 04/10/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Xu, Zheng
• Granted Patent: US 7,687,977 B2
• Time in Patent Office: Days
• US Class Current: 310/339
• CPC Class Codes: H10N 30/01 Manufacture or treatment
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

A micro-sized power source. A piezoelectric power generator, capable of harvesting energy from environmental vibration with lower level frequency, including a dielectric frame loosely containing a piezoelectric panel. The piezoelectric panel includes an electrode and a piezoelectric layer formed over an electrode and dielectric layer and an end mass formed on the piezoelectric layer. The end mass provides weight to cause the piezoelectric panel to move (vibrate) within the frame and causes the generation of electrical power.

Claims

1. A micro-sized power source, comprising:

a dielectric frame having a first electrode pad, said dielectric frame loosely supporting a piezoelectric panel thereon, the piezoelectric panel further comprising a second electrode pad; and

an end mass formed on the piezoelectric layer, the end mass providing weight to cause the piezoelectric panel to move within the frame and causes the generation of electrical power.

2. The micro-sized power source of claim 1 wherein the piezoelectric panel is composed of dielectric materials and the second electrode is formed as a piezoelectric layer formed over the piezoelectric panel.

3. The micro-sized power source of claim 1 wherein movement of the panel within the frame causes the generation of electrical power used to power a microelectronic system such as a sensor.

4. The micro-sized power source of claim 1 wherein electrical power is taken from a connection to the lower electrode pad and upper electrode pad.

5. The micro-sized power source of claim 1 wherein the lower electrode pad and upper electrode pad are comprised of at least one of:

platinum, titanium, gold, chromium.

6. The micro-sized power source of claim 1 wherein the lower electrode pad and upper electrode pad are comprised of a thickness in the range of 100˜

400 nm.

7. The micro-sized power source of claim 1 wherein said micro-sized power source operates with a low frequency (<

1000 Hz) vibration extracting capability

9. The micro-sized power source of claim 7 wherein the piezoelectric panel is composed of dielectric materials and the electrodes are formed as piezoelectric layers formed over the piezoelectric panel.

10. The micro-sized power source of claim 7 wherein movement of the panel within the frame causes the generation of electrical power used to power a microelectronic system such as a sensor.

11. The micro-sized power source of claim 7 wherein electrical power is taken from a connection to the lower electrode pad and upper electrode pad.

12. The micro-sized power source of claim 7 wherein the lower electrode pad and upper electrode pad are comprised of at least one of:

platinum, titanium, gold, chromium.

13. The micro-sized power source of claim 7 wherein the lower electrode pad and upper electrode pad are comprised of a thickness in the range of 100˜

400 nm.

8. A piezoelectric power generator including:

a piezoelectric panel including top and bottom electrode pads;

a dielectric frame loosely supporting the piezoelectric panel thereon; and

an end mass formed on the piezoelectric layer, the end mass providing weight to cause the piezoelectric panel to vibrate within the frame and causes the generation of electrical power.

14. A method of fabricating a micro-sized power source, comprising:

forming a dielectric layer having a top surface and a bottom surface;

forming a bottom electrode on the top surface of the dielectric layer;

forming a PZT deposition layer over the bottom electrode;

forming a top electrode over the PZT deposition layer;

forming an end mass having an outer edge over one end of the top electrode;

etching a notch through at least the dielectric frame near the edge of the top electrode near the outer edge of the end mass;

etching a window into the bottom surface of the dielectric layer to said notch, said window etched at a depth enabling the formation of a panel in the form of a cantilever supporting an end mass;

wherein movement of the panel by said end mass causes the generation of electrical power that can be obtained through the bottom and top electrodes.