Apparatus employing piezoelectric energy harvester capable of generating voltage to drive power conditioning circuit and method of manufacturing the same

• US 8,330,334 B2
• Filed: 01/05/2010
• Issued: 12/11/2012
• Est. Priority Date: 09/08/2009
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Sang Kyun, Moon, Seung Eon, Yang, Yil Suk, Park, Kang Ho, Kim, Jong Dae
• Primary Examiner(s): SAN MARTIN, JAYDI A
• Application Number:
  US12/652,177
• Publication Number:
  US 20110057458A1
• Time in Patent Office: 1,071 Days
• Field of Search: 310/339, 310/26
• US Class Current: 310/339
• CPC Class Codes: H10N 30/00 Piezoelectric or electrostrictive devices integrated devices or assemblies of multiple devices H10N39/00
• CPC Class Codes: H10N 30/306 Cantilevers
• CPC Class Codes: H10N 35/101 with mechanical input and electrical output, e.g. generators, sensors
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

Provided are a piezoelectric energy harvester and a method of manufacturing the same. The piezoelectric energy harvester is configured to obtain primary voltage from a piezoelectric layer vibrated to generate voltage and secondary voltage from a magnetostrictive layer vibrated to induce a change in magnetic field and a coil surrounding the magnetostrictive layer. Thus, it is possible to obtain sufficient voltage to drive a power conditioning circuit (PCC).

Claims

1. An apparatus, comprising:

a piezoelectric energy harvester; and

a power conditioning circuit (PCC) including a switch and configured to drive the switch to output a first voltage in accordance with displacement of the piezoelectric energy harvester, which is determined based on a second voltage,

wherein the piezoelectric energy harvester comprises;

a shim;

at least one piezoelectric layer configured to vibrate to generate the first voltage and formed over at least one of upper and lower surfaces of the shim;

at least one magnetostrictive layer configured to vibrate to induce a change in magnetic field and formed over the at least one piezoelectric layer; and

a coil configured to surround the piezoelectric layer and the magnetostrictive layer,

wherein, when the magnetostrictive layer vibrates and induces the change in magnetic field, a current flows through the coil to generate the second voltage, the second voltage being an AC voltage, and

wherein the first and second voltages are generated at substantially the same time due to the vibration.

2. The apparatus of claim 1, wherein the piezoelectric layer is formed of one of a piezoelectric ceramic material, a piezoelectric single crystal material, and a piezoelectric polymer.

3. The apparatus of claim 1, wherein the magnetostrictive layer is formed of Terfenol-D or Metglas 2605SC, which is a magnetostrictive material vibrating to induce the change in magnetic field.

4. A method of manufacturing an apparatus including a piezoelectric energy harvester and a power conditioning circuit (PCC), comprising:

providing a shim;

forming at least one piezoelectric layer over at least one upper and lower surfaces of the shim, the piezoelectric layer being configured to vibrate to generate a first voltage;

forming at least one magnetostrictive layer over the at least one piezoelectric layer, the magnetostrictive layer being configured to vibrate to induce a change in magnetic field;

surrounding the piezoelectric layer and the magnetostrictive layer with a coil to form the piezoelectric energy harvester, wherein, when the magnetostrictive layer vibrates, a current flows through the coil so that second voltage is generated, the second voltage being an AC voltage; and

providing the power conditioning circuit (PCC) that includes a switch and is configured to drive the switch to output the first voltage in accordance with displacement of the piezoelectric energy harvester, which is determined based on the second voltage,

wherein the first and second voltages are generates at substantially the same time due to the vibration.

5. The method of claim 4, wherein the piezoelectric layer is formed of one of a piezoelectric ceramic material, a piezoelectric single crystal material, and a piezoelectric polymer.

6. The method of claim 4, wherein the magnetostrictive layer is formed of Terfenol-D or Metglas 2605SC, which is a magnetostrictive material capable of vibrating to induce the change in magnetic field.