Nanomechanical Oscillator

• US 20090294638A1
• Filed: 01/04/2006
• Published: 12/03/2009
• Est. Priority Date: 01/07/2005
• Status: Active Grant

• Current Assignee: Trustees of Boston University
• Original Assignee: Trustees of Boston University
• Inventors: Badzey, Robert, Mohanty, Pritiraj, Zolfagharkhani, Guiti, Gaidarzhy, Alexei
• Granted Patent: US 8,063,535 B2
• Time in Patent Office: Days
• US Class Current: 250/234
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 2009/02519 Torsional
• CPC Class Codes: H03H 2009/02527 Combined
• CPC Class Codes: H03H 9/2431 Ring resonators
• CPC Class Codes: H03H 9/2447 Beam resonators H03H9/2468 takes precedence
• CPC Class Codes: H03H 9/485 for microelectro-mechanical filters
• CPC Class Codes: H03H 9/505 for microelectro-mechanical filters

Abstract

A mechanical oscillator has components with dimensions in a sub-micron range to produce resonance mode oscillations in a gigahertz range. A major element is coupled to a minor, sub-micron element to produce large amplitude gigahertz frequency oscillation that is detected with readily available techniques. The mechanical structure can be formed according to a number of geometries including beams and rings and is excited with electrostatic, magnetic and thermal related forces, as well as other excitation techniques. The mechanical structure can be arranged in arrays for applications such as amplification and mixing and is less sensitive to shock and radiative environments than electrical or optical counterparts.

Claims

1. A mechanical oscillator, comprising:

a major element forming a first vibrational structure;

a support coupled to the major element for suspending the major element to permit the major element to oscillate;

a minor element coupled to the major element to form a second vibrational structure;

a collective resonance mode oscillation frequency achieved through cooperation of the major and minor elements when excited to vibrate; and

the minor element having an overall large dimension in a sub-micron range.

2. The oscillator according to claim 1, wherein the collective mode oscillation has a supra-megahertz frequency.

3. The oscillator according to claim 1, further comprising another support for suspending the major element, wherein the major element is a doubly clamped beam.

4. The oscillator according to claim 1, wherein the minor element is a cantilever beam elastically coupled to the major element.

5. The oscillator according to claim 3, wherein the minor element is a cantilever beam elastically coupled to the doubly clamped beam.

6. The oscillator according to claim 1, further comprising an electrode coupled to one or more of the major element or minor element and operable to communicate a signal generated by oscillation of the oscillator.

7. The oscillator according to claim 6, wherein the electrode permits communication of an electrical signal generated by oscillation of the oscillator.

8. The oscillator according to claim 1, further comprising a material and an arrangement of the material in the oscillator suitable for contributing to enabling excitation of the oscillator, wherein the excitation is selected from the group consisting of electrocapacitive, optical, piezoelectric, piezoresistive, magnetomotive and magnetic excitation.

9. The oscillator according to claim 1, wherein the oscillator is composed of a material selected from the group consisting of silicon, diamond, quartz, GaAs, GaN, SiC, SiN, pure metals, bimetallic strips, heterogeneous semiconductor and metal compositions, heterogeneous compositions of a plurality of semiconductor material, or combinations of the above.

10. The oscillator according to claim 1, further comprising an intermediate element interposed between the major and minor elements.

11. The oscillator according to claim 1, further comprising a plurality of major elements.

12. The oscillator according to claim 1, wherein a portion of the major element further comprises a geometry selected from the group consisting of cantilevers, free-free bridges, free-clamped bridges, clamped-clamped bridges, discs, rings, prisms, cylinders, tubes, spheres, shells, springs, polygons, diaphragms and tori.

13. The oscillator according to claim 1, wherein a portion of the minor element further comprises a geometry selected from the group consisting of cantilevers, free-free bridges, free-clamped bridges, clamped-clamped bridges, discs, rings, prisms, cylinders, tubes, spheres, shells, springs, polygons, diaphragms and tori.

14. The oscillator according to claim 10, wherein a portion of the intermediate element further comprises a geometry selected from the group consisting of cantilevers, free-free bridges, free-clamped bridges, clamped-clamped bridges, discs, rings, prisms, cylinders, tubes, spheres, shells, springs, polygons, diaphragms and tori.

15. The oscillator according to claim 1, wherein the resonance modes further comprise vibration types selected from the group consisting of torsional, transverse, shear, longitudinal compression or tension, dilatational and rotation.

16. A circuit including a number of inter-coupled components, wherein one or more of the components is the oscillator according to claim 1.

17. The circuit according to claim 16, wherein the circuit is a type selected from the group consisting of electrical, mechanical, magnetic, optical and electromechanical.

18. An array of oscillators, wherein one or more is the oscillator according to claim 1.

19. The array according to claim 18, wherein the oscillators are interrelated to form a phased array.

20. The oscillator according to claim 1, further comprising a DC bias source coupled to the oscillator for applying a DC bias to the oscillator.

21. The oscillator according to claim 7, further comprising an AC current source coupled to the oscillator for applying an AC current to the electrode.

22. The oscillator according to claim 20, further comprising a shifted collective resonance mode oscillation frequency when a DC bias is applied from the DC bias source.

23. The oscillator according to claim 1, further comprising an arrangement of the major and minor elements to obtain a non-linear response when the oscillator is excited under predetermined conditions.

24. The oscillator according to claim 1, further comprising an arrangement of the major and minor elements to produce a multi-stable response when the oscillator is excited under predetermined conditions.

25. The oscillator according to claim 1, wherein the oscillation frequency is in the range of from about 1 kHz to about 1 THz.

26. A scanning probe microscopy device for sensing characteristics of a scanned surface, comprising a probe tip coupled to a vibrational support, wherein the vibrational support is the oscillator according to claim 1.

27. A method for generating a high-frequency signal, comprising:

applying an excitation drive to a mechanical oscillation structure having a major element suspended from a support and sub-micron micron minor elements coupled to the major element to produce oscillation in the mechanical oscillation structure; and

sensing the oscillation to produce the high-frequency signal.

28. The method according to claim 27, wherein applying an excitation further comprises utilizing an excitation type selected from the group consisting of electrostatic force, piezoelectric strain, magnetic attraction, magnetomotive force and thermal expansion and contraction.

29. The method according to claim 27, wherein sensing further comprises utilizing a detection type selected from the group consisting of electrostatic force, piezoelectric strain, piezoresistive strain, magnetic attraction, magnetomotive force, thermal expansion and contraction and optical.

30. The method according to claim 27, wherein vibration of the mechanical structure is of a type selected from the group consisting of torsional, transverse, shear, longitudinal compression or tension, dilatational or rotation.

31. The method according to claim 27, further comprising applying an excitation to another mechanical oscillation structure in a relationship with the one mechanical oscillation structure to produce a cooperative array of coherent mechanical oscillation structures.

32. The method according to claim 27, wherein applying the excitation further comprises applying an AC current to the mechanical oscillation structure.

33. The method according to claim 27, further comprising applying a DC bias to the mechanical oscillation structure to shift a collective resonance mode oscillation frequency.

34. The method according to claim 27, wherein applying the excitation further comprises producing a non-linear response in the mechanical oscillation structure.

35. The method according to claim 27, wherein applying the excitation further comprises producing a multi-stable response in the mechanical oscillation structure.

36. The method according to claim 27, further comprising producing indicia of quantum mechanical behavior.

37. The method according to claim 27, wherein applying the excitation drive further comprises producing an oscillation frequency in the range of from about 1 kHz to about 1 THz.