System and method for resonance frequency tuning of resonant devices

• US 8,154,176 B2
• Filed: 04/07/2009
• Issued: 04/10/2012
• Est. Priority Date: 04/07/2008
• Status: Expired due to Fees

• Current Assignee: Stichting Imec Nederland
• Original Assignee: Stichting Imec Nederland
• Inventors: Karakaya, Koray, Hohlfeld, Dennis
• Primary Examiner(s): SAN MARTIN, JAYDI A
• Application Number:
  US12/420,045
• Publication Number:
  US 20090284102A1
• Time in Patent Office: 1,099 Days
• Field of Search: 310330-332, 310/339
• US Class Current: 310/339
• CPC Class Codes: F16F 15/02 Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems F16F15/005 takes precedence ; layered products B32B; suppression of vibration in ships B63; relieving load on bearings, using magnetic means F16C39/06
• CPC Class Codes: G01H 11/08 using piezoelectric devices
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H10N 30/306 Cantilevers
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

Tunable vibration energy scavengers and methods of operating the same are disclosed. The disclosed energy scavengers comprise a beam with a main body, wherein the beam comprises at least one flap and means for changing a shape of the at least one flap, wherein the at least one flap is physically attached to the main body along a longitudinal side of the main body. The disclosed methods comprise tuning the shape of the at least one flap, thereby tuning the stiffness of the structure.

Claims

1. A method for tuning a resonance frequency of a structure, wherein the method comprises:

providing the structure, wherein (i) the structure comprises a beam with a main body and at least one flap located along a longitudinal side of the main body, (ii) the at least one flap is physically attached to the main body, and (iii) a thickness of the at least one flap is at least a factor of ten smaller than a thickness of the main body; and

tuning a shape of the at least one flap, thereby tuning a stiffness of the structure.

2. The method of claim 1, wherein tuning the shape of the at least one flap comprises tuning a curvature of the at least one flap.

3. The method of claim 1, wherein tuning the shape of the at least one flap comprises actuating a piezoelectric actuator on the at least one flap.

4. The method of claim 1, wherein the structure is one of a vibration energy scavenger and a sensor.

5. A resonant device with tunable resonance frequency, the resonant device comprising:

at least one beam comprising a main body and at least one flap located along a longitudinal side of the main body, wherein (i) the at least one flap is physically attached to the main body and (ii) a thickness of the at least one flap is at least a factor of ten smaller than a thickness of the main body; and

means for changing a shape of the at least one flap.

6. The resonant device of claim 5, wherein the means for changing the shape of the at least one flap comprise a piezoelectric stack comprising a bottom electrode, a piezoelectric material layer, and a top electrode, wherein the piezoelectric stack is located on a surface of the at least one flap.

7. The resonant device of claim 5, further comprising a seismic mass attached to the at least one beam.

8. The resonant device of claim 5, wherein the at least one beam is a cantilever structure.

9. The resonant device of claim 5, wherein the at least one beam is clamped at two sides.

10. The resonant device of claim 5, wherein the resonant device is one of a micro-electro-mechanical system device and a nano-electro-mechanical device.

11. The resonant device of claim 5, wherein the resonant device is one of a vibration energy scavenger and a sensor.

12. A method of fabricating a resonant device, the method comprising:

providing a beam comprising a main body and at least one flap located along a longitudinal side of the main body, wherein (i) the at least one flap is physically attached to the main body, and (ii) a thickness of the at least one flap is at least a factor of ten smaller than a thickness of the main body; and

providing a flap actuator for tuning the shape of the at least one flap, thereby tuning the stiffness of the resonant device.

13. The method of claim 12, wherein providing the flap actuator comprises providing a piezoelectric actuator.

14. The method of claim 12, further comprising using the resonant device as one of a vibration energy scavenger and a sensor.