Applications and methods of operating a three-dimensional nano-electro-mechanical resonator and related devices

• US 8,435,798 B2
• Filed: 01/12/2011
• Issued: 05/07/2013
• Est. Priority Date: 01/13/2010
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Kaul, Anupama B., Epp, Larry W., Bagge, Leif
• Primary Examiner(s): Xu, Robert
• Application Number:
  US13/005,511
• Publication Number:
  US 20110212535A1
• Time in Patent Office: 846 Days
• Field of Search: None
• US Class Current: 436/149
• CPC Class Codes: G01N 2291/0255 (Bio)chemical reactions, e.g. on biosensors
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B

Abstract

Carbon nanofiber resonator devices, methods for use, and applications of said devices are disclosed. Carbon nanofiber resonator devices can be utilized in or as high Q resonators. Resonant frequency of these devices is a function of configuration of various conducting components within these devices. Such devices can find use, for example, in filtering and chemical detection.

Claims

1. A method of operating a nano-electro-mechanical resonator, comprising:

applying to a first structural member of the resonator, a voltage signal containing an alternating current (AC) component, the first structural member having a non-contacting proximity relationship with a second structural member, the second structural member comprising a carbon nanofiber, the non-contacting proximity relationship characterized at least in part by;

a) a gap width separating the first structural member from the carbon nanofiber and b) a coupling length factor defined on the basis of a portion of the first structural member that is oriented substantially parallel to a portion of the carbon nanofiber; and

producing mechanical resonance on the carbon nanofiber via the voltage signal, thus operating the nano-electro-mechanical resonator wherein the first structural member is one of;

a) a nanoprobe, b) another carbon nanofiber or c) a metal rod.

2. The method according to claim 1, wherein the first structural member is a nanoprobe.

3. The method according to claim 1, wherein the voltage signal further contains a direct current bias higher than a gating voltage.

4. The method according to claim 1, wherein the carbon nanofiber comprises conductive sidewalls.

5. The method according to claim 1, wherein the gap width is less than a threshold gap width for producing mechanical resonance on the carbon nanofiber.

6. The method according to claim 1, wherein the coupling length is greater than a threshold coupling length for producing mechanical resonance on the carbon nanofiber.

7. The method according to claim 1, further comprising:

selecting length, inner diameter, and outer diameter of the carbon nanofiber based on a target resonant frequency at which to operate the nano-electro-mechanical resonator.

8. The method according to claim 1, further comprising:

generating an output voltage signal containing an output alternating current component on a third structural member by coupling the third structural member to the mechanical resonance on the carbon nanofiber.

9. The method of claim 8, wherein phase difference between the output alternating current component of the output voltage signal and the alternating current component of the input voltage signal is 180 degrees.

10. The method according to claim 1, further comprising generating an output optical signal based on the mechanical resonance on the carbon nanofiber.

11. The method according to claim 2, wherein the nanoprobe comprises tungsten.

12. The method according to claim 2, wherein the nanoprobe has a tapered portion.

13. The method according to claim 12, wherein the nanoprobe has a planar portion opposing the tapered portion, the planar portion configured to provide the gap width and coupling length factor with respect to the carbon nanofiber.

14. The method of claim 1, further comprising:

selecting the coupling length on the basis of a Q value, wherein the Q value is directly proportional to the coupling length.

15. The method of claim 1, further comprising:

selecting the gap width on the basis of a Q value, wherein the Q value is inversely proportional to the gap width.

16. The method of claim 15, wherein the mechanical resonance comprises a deflection amplitude, the deflection amplitude inversely proportional to the square of the gap width.

17. The method of claim 1, further comprising:

using the first structural member to mechanically deflect the carbon nanofiber.

18. The method of claim 17, wherein deflecting the carbon nanofiber comprises bending the carbon nanofiber to a first bending angle.

19. The method of claim 18, wherein the first bending angle is approximately 70 degrees.

20. The method of claim 19, wherein bending the carbon nanofiber to approximately 70 degrees is characterized by the carbon nanofiber returning to an initial position without delaminating from a substrate upon which the carbon nanofiber is anchored.

21. The method of claim 19, wherein bending the carbon nanofiber to approximately 70 degrees is characterized by the carbon nanofiber returning to an initial position without fracturing the carbon nanofiber.

22. The method of claim 18, further comprising:

bending the carbon nanofiber multiple times to test for robustness of the carbon nanofiber in producing mechanical resonance.