Piezoelectric Power Generator and Wireless Sensor Network Apparatus

• US 20120074812A1
• Filed: 12/05/2011
• Published: 03/29/2012
• Est. Priority Date: 06/26/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Fujimoto, Katsumi
• Granted Patent: US 8,604,674 B2
• Time in Patent Office: Days
• US Class Current: 310/323.01
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

A piezoelectric power generator that includes a piezoelectric multilayer body including a piezoelectric element that converts vibration into electricity and a substrate on which the piezoelectric multilayer body is mounted. The resonant frequency of the piezoelectric element coincides with the reference of the substrate so that the piezoelectric element efficiently vibrates. The addition of vibration portions in the substrate allows various resonant frequencies to be set.

Claims

1. A piezoelectric power generator comprising:

a substrate;

a piezoelectric element that converts vibration into electricity mounted on the substrate,

wherein a resonant frequency of the piezoelectric element coincides with a resonant frequency of the substrate.

2. The piezoelectric power generator according to claim 1, wherein the piezoelectric element is configured to vibrate in a bending vibration mode, and the resonant frequency of the substrate coincides with a resonant frequency of the bending vibration mode.

3. The piezoelectric power generator according to claim 1, wherein the substrate includes at least one vibration portion, and a resonant frequency of the vibration portion coincides with the resonant frequency of the piezoelectric element.

4. The piezoelectric power generator according to claim 3, wherein the at least one vibration portion is a notch.

5. The piezoelectric power generator according to claim 1, wherein the substrate includes a first vibration portion and a second vibration portion, and a resonant frequency of the first vibration portion and a resonant frequency of the second vibration portion are different from each other.

6. A wireless sensor network apparatus comprising:

a substrate;

a piezoelectric power generator mounted on the substrate, the piezoelectric power generator including a piezoelectric element configured to convert vibration into electricity;

a wireless communication apparatus mounted on the substrate; and

a sensor element mounted on the substrate,

wherein a resonant frequency of the piezoelectric element coincides with a resonant frequency of the substrate.

7. The wireless sensor network apparatus according to claim 6, wherein the wireless communication apparatus is an antenna.

8. The piezoelectric power generator according to claim 6, wherein the piezoelectric element is configured to vibrate in a bending vibration mode, and the resonant frequency of the substrate coincides with a resonant frequency of the bending vibration mode.

9. The wireless sensor network apparatus according to claim 6, wherein the substrate includes at least one vibration portion, and a resonant frequency of the vibration portion coincides with the resonant frequency of the piezoelectric element.

10. The piezoelectric power generator according to claim 9, wherein the at least one vibration portion is a notch.

11. The piezoelectric power generator according to claim 6, wherein the substrate includes a first vibration portion and a second vibration portion, and a resonant frequency of the first vibration portion and a resonant frequency of the second vibration portion are different from each other.