APPLICATIONS AND METHODS OF OPERATING A THREE-DIMENSIONAL NANO-ELECTRO-MECHANICAL RESONATOR AND RELATED DEVICES

• US 20110212535A1
• Filed: 01/12/2011
• Published: 09/01/2011
• Est. Priority Date: 01/13/2010
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Epp, Larry W., Bagge, Leif, Kaul, Anupama B.
• Granted Patent: US 8,435,798 B2
• Time in Patent Office: Days
• 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:

providing the nano-electro-mechanical resonator, wherein the nano-electro-mechanical resonator comprises;

a first electrical conductor; and

a second electrical conductor comprising at least one carbon nanofiber;

applying a voltage signal containing an alternating current component between the first and the second electrical conductor; and

producing mechanical resonance on the second electrical conductor via the voltage signal, thus operating the nano-electro-mechanical resonator.

2. The method according to claim 1, wherein the applying comprises applying the voltage signal to the first electrical conductor and grounding the second electrical conductor.

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 providing the nano-electro-mechanical resonator comprises positioning the second electrical conductor at a gap width from the first electrical conductor, and wherein the gap width is less than a threshold gap width.

6. The method according to claim 1, wherein the providing the nano-electro-mechanical resonator comprises positioning the second electrical conductor with an coupling length from the first electrical conductor, and wherein the coupling length is greater than a threshold coupling length.

7. The method according to claim 1, wherein the providing the nano-electro-mechanical resonator comprises selecting length, inner diameter, and outer diameter of the at least one 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:

providing a third electrical conductor; and

generating an output voltage signal containing an output alternating current component on the third electrical conductor by coupling the third electrical conductor to the mechanical resonance on the second electrical conductor.

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 second electrical conductor.

11. A method of operating a nano-electro-mechanical resonator as a chemical detector, comprising:

providing a nano-electro-mechanical resonator, wherein the nano-electro-mechanical resonator comprises;

a first electrical conductor; and

a second electrical conductor comprising at least one carbon nanofiber with a functionalized layer suitable for binding to at least one selected type of chemical species, wherein the at least one selected type of chemical species is in a chemical-containing fluid;

applying a voltage signal containing an alternating current component between the first and the second electrical conductor;

producing a first mechanical resonance on the second electrical conductor by the voltage signal;

contacting the chemical-containing fluid with the nano-electro-mechanical resonator such that the at least one selected type of chemical species binds to the functionalized layer of the second electrical conductor;

producing a second mechanical resonance on the second electrical conductor, wherein the second mechanical resonance is different from the first mechanical resonance; and

detecting the at least one selected type of chemical species in the chemical-containing fluid to the functionalized layer of the second electrical conductor, wherein the detecting comprises binding of the at least one selected type of chemical species to the functionalized layer and changing mass of the second electrical conductor, and wherein the changing mass produces the second mechanical resonance.

12. The method according to claim 11, further comprising:

providing a third electrical conductor; and

generating an output voltage signal containing an output alternating current component on the third electrical conductor by coupling the third electrical conductor to the first mechanical resonance on the second electrical conductor.

13. The method according to claim 12, wherein phase difference between the output alternating current component of the output voltage signal and the alternating current component of the voltage signal is 180 degrees.

14. The method according to claim 11, further comprising generating an output optical signal based on the first mechanical resonance on the second electrical conductor.

15. A nano-electro-mechanical resonator, comprising:

a first electrical conductor; and

a second electrical conductor comprising at least one carbon nanofiber, the second electrical conductor positioned at a gap width from the first electrical conductor and positioned at a coupling length with the first electrical conductor,

wherein the first and the second electrical conductor are configured to electro-mechanically couple when a voltage signal containing an alternating current component is applied between the first and the second electrical conductor, and wherein a first mechanical resonance is produced on the second electrical conductor, thus forming a nano-electro-mechanical resonator.

16. The resonator of claim 15, wherein the carbon nanofiber comprises conductive sidewalls.

17. The resonator of claim 15, wherein the carbon nanofiber is substantially perpendicular to a substrate.

18. The resonator of claim 17, wherein the substrate is selected from the group consisting of silicon, refractory metal, and nitride.

19. The resonator of claim 18, wherein the substrate comprises a layer of niobium titanium nitride (NbTiN).

20. The resonator of claim 15, wherein the gap width between the second electrical conductor and the first electrical conductor is less than a threshold gap width.

21. The resonator of claim 15, wherein the coupling length between the second electrical conductor and the first electrical conductor is greater than a threshold coupling length.

22. The resonator of claim 15, wherein the at least one carbon nanofiber has length, inner diameter, and outer diameter selected based on a target resonant frequency at which to operate the NEMR.

23. The resonator of claim 15, further comprising a third electrical conductor, the third electrical conductor configured for generating an output voltage signal containing an output alternative current component by coupling of the third electrical conductor to the mechanical resonance on the second electrical conductor.

24. The resonator of claim 15, further comprising an optical detection system configured for generating an output optical signal based on the mechanical resonance on the second electrical conductor.

25. The resonator of claim 15, wherein the at least one carbon nanofiber of the second electrical conductor further comprises a functionalized layer suitable for binding to at least one selected type of chemical species, and wherein the second electrical conductor is configured to produce a second mechanical resonance, thus indicating binding of the at least one selected type of chemical species to the functionalized layer.