PIEZOELECTRIC APPARATUS FOR HARVESTING ENERGY FOR PORTABLE ELECTRONICS AND METHOD FOR MANUFACTURING SAME

• US 20140077662A1
• Filed: 09/19/2013
• Published: 03/20/2014
• Est. Priority Date: 09/19/2012
• Status: Abandoned Application

• Current Assignee: The Governors of the University of Alberta (University of Alberta)
• Original Assignee: The Governors of the University of Alberta (University of Alberta)
• Inventors: Moussa, Walied Ahmed Mohamed, Lueke, Jonathan Sierzant
• Application Number:
  US14/032,018
• Publication Number:
  US 20140077662A1
• Time in Patent Office: Days
• US Class Current: 310/339
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H10N 30/01 Manufacture or treatment
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

This disclosure presents an advanced design of an energy harvester that utilizes a piezoelectric element to convert vibration to electricity. The advanced design is based on a fixed-fixed folded beam. An aqua regia wet etching and PZT sol-gel deposition/patterning processes can be used to manufacture the energy harvester.

Claims

1. An apparatus for harvesting energy from mechanical motion, comprising:

a) a piezoelectric transducer configured for converting mechanical motion into electrical energy, wherein the transducer further comprises;

i) a piezoelectric beam element that is folded into a structure that comprises at least two parallel beam lengths that define an intervening void space,

ii) a proof mass disposed at a first end of the beam element, and

iii) a clamp element disposed at a second end of the beam element; and

b) a storage element for storing electrical energy produced by the transducer.

2. An apparatus for harvesting energy from mechanical motion, comprising:

a) a piezoelectric transducer configured for converting mechanical motion into electrical energy, wherein the transducer further comprises;

i) a piezoelectric beam element that is folded into a structure that comprises at least two parallel beam lengths that define an intervening void space between each of the beam lengths,

ii) a first clamp disposed at a first end of the beam element, and

iii) a second clamp element disposed at a second end of the beam element; and

b) a storage element for storing electrical energy produced by the transducer.

3. The apparatus of claim 2, wherein the transducer comprises a plurality of folded beam elements arranged in a parallel.

4. The apparatus of claim 2 wherein the transducer comprises a plurality of folded beam elements arranged in series.

5. The apparatus of claim 2 wherein the piezoelectric beam element includes a piezoelectric thin film.

6. The apparatus of claim 5 wherein the piezoelectric thin film is a lead zirconate titanate (“

PZT”

) thin film.

7. A method for manufacturing the apparatus of claim 2, the method comprising the step of using an aqua regia etching and lead zirconate titanate (“

PZT”

) sol-gel deposition/patterning process to manufacture the apparatus.

8. A method of manufacturing a piezoelectric transducer configured for converting mechanical motion into electrical energy, wherein the transducer includes a piezoelectric beam element that is folded into a structure that comprises at least two parallel beam lengths that define an intervening void space, comprising the steps of:

a) providing a silicon wafer;

b) depositing titanium and platinum metallic layers on the wafer;

c) defining a pattern on the metallic layers;

d) depositing a PZT sol-gel;

e) patterning the PZT sol-gel;

f) etching a geometry for the folded piezoelectric beam element.

9. The method of claim 8 wherein the titanium and platinum layers are deposited using aqua regia etching.

10. The method of claim 8 wherein the titanium and platinum layers are deposited using a lift-off process.