Pattern-aligned carbon nanotube growth and tunable resonator apparatus

• US 20020167374A1
• Filed: 04/01/2002
• Published: 11/14/2002
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Brian D. Hunt, Daniel J. Hoppe, Daniel S. Choi, Flavio Noca, Larry Epp, Michael E. Hoenk, Robert S. Kowalcyk
• Original Assignee: Brian D. Hunt, Daniel J. Hoppe, Daniel S. Choi, Flavio Noca, Larry Epp, Michael E. Hoenk, Robert S. Kowalcyk
• Inventors: Kowalcyk, Robert S., Hunt, Brian D., Choi, Daniel S., Noca, Flavio, Hoenk, Michael E., Hoppe, Daniel J., Epp, Larry
• Granted Patent: US 6,803,840 B2
• Time in Patent Office: Days
• US Class Current: 333/186
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 3/0072 of microelectro-mechanical resonators or networks micromembranes or microbeams B81B2203/01; manufacture of microstructural devices in general B81C
• CPC Class Codes: H03H 3/0077 by tuning of resonance frequency
• CPC Class Codes: H03H 9/02409 by application of a DC-bias voltage H03H9/02417 takes precedence
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators
• CPC Class Codes: Y10S 977/932 for electronic or optoelectronic application

Abstract

A tunable nanomechanical oscillator device and system is provided. The nanomechanical oscillator device comprising at least one nanoresonator, such as a suspended nanotube, designed such that injecting charge density into the tube (e.g. by applying a capacitively-cuopled voltage bias) changes the resonant frequency of the nanotube, and where exposing the resonator to an RF bias induces oscillitory movement in the suspended portion of the nanotube, forming a nanoscale resonator, as well as a force sensor when operated in an inverse mode. A method of producing an oriented nanoscale resonator structure with integrated electrodes is also provided.

Claims

1. A tunable nanoresonator comprising:

a support structure;

a tuning power source for producing a tuning bias;

an RF signal power device comprising at least one of an RF bias emitter and a bias detector; and

at least one resonating member, wherein at least one portion of the resonating member is fixedly attached to the support structure and at least one portion of the member is free to oscillate at a resonant frequency, the resonating member in signal communication with the tuning power source such that a tuning bias applied to the resonating member alters the resonant frequency of the resonating member, the resonating member in further signal communication with the signal power device such that an RF bias applied to the resonating member by the RF signal power device induces an oscillatory motion in the resonating member and such that oscillatory motion of the resonating member induces a voltage or current measurable by the RF signal power device.

2. The tunable nanoresonator according to claim 1 wherein the substrate is made of a material selected from the group consisting of silicon, alumina, glass, sapphire or quartz.

3. The tunable nanoresonator according to claim 2 wherein the substrate further comprises a plurality of electrodes sufficient such that the resonating member is fixedly attached to the support structure through an electrode, wherein the electrodes are in signal communication with the RF signal power device and wherein the resonating member is in signal communication with the RF signal power device through the electrode.

4. The tunable nanoresonator according to claim 3 wherein the electrodes are made of a metal selected from the group consisting of gold, platinum and titanium.

5. The tunable nanoresonator according to claim 1 wherein the resonating member is fixedly attached to the support structure at two points.

6. The tunable nanoresonator according to claim 1 wherein the substrate further comprises a plurality of catalytic spots deposited thereon wherein the resonating member is fixedly attached to the support structure through a catalytic spot.

7. The tunable nanoresonator according to claim 6 wherein the catalytic material is selected from the group consisting of Fe, Ti, Ni, Co, Mo, Ni/Co alloy, and Ni/Ti alloy.

8. The tunable nanoresonator according to claim 1 wherein the tuning power source is selected from the group consisting of:

a light source, a voltage source, a current source, and a magnetomotive source.

9. The tunable nanoresonator according to claim 1 wherein the RF signal power device is a voltage detector.

10. The tunable nanoresonator according to claim 1 wherein the resonating member has a cross-sectional dimension of about 1 to 100 nm.

11. The tunable nanoresonator according to claim 1 comprising at least two support structures wherein the space between the support structures has a dimension of about 10 to 200 nm.

12. The tunable nanoresonator according to claim 1 wherein the device operates as one of an oscillator and a sensor.

13. The tunable nanoresonator according to claim 1 wherein the nanoresonator comprises at least two support structures and wherein the resonating member is attached at either end to one of the at least two support structures.

14. The tunable nanoresonator according to claim 1 wherein the device is an oscillator selected from the group consisting of:

an RF filter, a signal processor, and a micro-gyroscope.

15. The tunable nanoresonator according to claim 1 wherein the device is one of either a force-based sensor and an RF frequency sensor.

16. The tunable nanoresonator according to claim 1 comprising a plurality of resonating members of varying lengths.

17. The tunable nanoresonator according to claim 1 wherein the resonating member is made of carbon.

18. The tunable nanoresonator according to claim 1 wherein the resonating member is grown by self-assembly on the substrate.

19. The tunable nanoresonator according to claim 1 wherein the resonating member is one of either a nanotube or a nanorod.

20. The tunable nanoresonator according to claim 1 wherein the resonating member is chemically or biologically functionalized.

21. The tunable nanoresonator according to claim 1 wherein the outer surface of the resonating member is treated to increase the resistance of the resonating member.

22. The tunable nanoresonator according to claim 1, further comprising a device body defining an internal volume wherein the resonating member is confined within the internal volume.

23. The tunable nanoresonator according to claim 22, wherein one of the substrate or device body is transparent.

24. The tunable nanoresonator according to claim 22 wherein the device body is made of a material selected from the group consisting of silicon, alumina, glass, sapphire, and quartz.

25. The tunable nanoresonator according to claim 1 wherein the RF induced motion of the resonating member is proportional to the potential applied to the resonating member.

26. The tunable nanoresonator according to claim 1 wherein the motion induced potential of the resonating member is proportional to the degree of motion of the resonating member.

27. The tunable nanoresonator according to claim 1 wherein the device is disposed in a liquid environment.

28. The tunable nanoresonator according to claim 1 wherein the device is disposed in a vacuum environment.

29. The tunable nanoresonator according to claim 1 wherein the device is disposed in a gaseous environment.

30. The tunable nanoresonator according to claim 1 comprising at least two resonating members wherein at least one of the resonating members is operated as a sensor and at least one of the resonating members is operated as an oscillator.

31. The tunable nanoresonator according to claim 1 comprising at least two resonating members wherein the resonating members are operated as sensors, wherein each sensor is designed to detect a different substance.

32. The tunable nanoresonator according to claim 1 comprising at least two resonating members wherein the resonating members are operated as sensors, wherein all the sensors are designed to detect a single substance.

33. The tunable nanoresonator according to claim 1 comprising at least two resonating members wherein the resonating members are operated as oscillators, wherein the oscillators are designed with different resonant frequencies.

34. The tunable nanoresonator according to claim 1 wherein the support structure defines a substrate, and wherein the substrate further comprises a depressed portion, and where the resonating member is formed over the depressed portion in the plane defined by the substrate.

35. The tunable nanoresonator according to claim 1 wherein the support structure has an area of about 1 mm² to 1 cm².

39. The method according to claim 38 wherein the substrate is made of a material selected from the group consisting of silicon, alumina, glass or sapphire.

40. The method according to claim 38 further comprising depositing electrodes onto the substrate at the catalytic spot, wherein the electrode is in signal communication with a power device and wherein the nanoresonator is in signal communication with the power device through the electrodes.

41. The method according to claim 40 wherein the electrodes are made of a metal selected from the group consisting of gold, platinum and titanium.

42. The method according to claim 40 wherein each resonating member is attached to multiple electrodes.

43. The method according to claim 38 wherein the catalytic material is selected from the group consisting of Fe, Ti, Ni, Co, Mo, Ni/Co alloy, and Ni/Ti alloy.

44. The method according to claim 40 wherein the power device is a power source selected from the group consisting of:

a light source, an voltage source, a current source, and a magnetomotive source.

45. The method according to claim 40 wherein the power device is a voltage detector.

46. The method according to claim 38 wherein the resonating members have a cross-sectional dimension of about 1 to 100 nm.

47. The method according to claim 38 wherein the resonating members have a length dimension of about 10 to 200 nm.

48. The method according to claim 38 wherein a plurality of nanoresonators are grown and arranged on the substrate.

49. The method according to claim 38 wherein the catalyst spots are deposited by one of either an electron beam or sputter deposition method.

50. The method according to claim 38 wherein the resonating members are grown by self-assembly on the substrate.

51. The method according to claim 38 wherein the resonating members are nanotubes.

52. The method according to claim 38 wherein the feedstock consists at least partially of a carbon-based gas.

53. The method according to claim 38 wherein the feedstock consists at least partially of ethylene.

54. The method according to claim 38 wherein the growth temperature is at least 400°

C.

55. The method according to claim 38 wherein the growth temperature is between about 500 and 650°

C.

56. The method according to claim 38 wherein the substrate is a processed CMOS circuit.

57. The method according to claim 38 wherein the resonating members are chemically or biologically functionalized.

58. The method according to claim 38 wherein the outer surface of the resonating members are treated to increase the resistance of the resonating members.

59. The method according to claim 38 wherein the substrate has an area of about 0.1 mm² to 1 cm².

60. The method according to claim 38 wherein the growth step is conducted in a low pressure atmosphere of the feedstock.

61. The method according to claim 60 wherein the pressure of the feedstock is about 5 Torr.

62. The method according to claim 38 wherein the feedstock comprises ethylene diluted in at least one of the gases selected from the group consisting of:

nitrogen, ammonia and hydrogen.

63. The method according to claim 38 wherein the substrate has at least two support structures, and where the growth orienting structure orients the growth of the resonating member such that the resonating member grows between the two support structures.

64. The method according to claim 38 wherein the growth orienting structure is selected from the group consisting of:

a cantilever and a trench.

36. A tunable nanoresonator comprising:

at least two support structures;

a tuning power source for producing a tuning bias;

an RF signal power device comprising at least one of an RF bias emitter and a bias detector; and

at least one resonating carbon nanotube member, wherein both ends of the carbon nanotube member are fixedly attached to one of the at least two support structures and at least one portion of the member is suspended such that the portion is free to oscillate at a resonant frequency, the resonating member in signal communication with the tuning power source such that a tuning bias applied to the resonating member alters the resonant frequency of the resonating member, the resonating member in further signal communication with the signal power device such that an RF bias applied to the resonating member by the RF signal power device induces an oscillatory motion in the resonating member and such that oscillatory motion of the resonating member induces a voltage or current measurable by the RF signal power device.

37. A tunable nanoresonator comprising:

at least two support structures;

a tuning power source for producing a tuning bias;

a bias detector; and

at least two resonating carbon nanotube members, wherein both ends of the at least two carbon nanotube members are fixedly attached to at least one of the at least two support structures and at least one portion of the member is suspended such that the portion is free to oscillate at a resonant frequency, the resonating member in signal communication with the tuning power source such that a tuning bias applied to the resonating member alters the resonant frequency of the resonating member, the resonating member in further signal communication with the bias detector such that an RF bias applied to the resonating member induces an oscillatory motion in the resonating member and such that oscillatory motion of the resonating member induces a voltage or current measurable by the bias detector.

38. A method of forming a nanoresonator comprising:

providing a substrate including at least one support structure and a growth orienting structure;

depositing at least one catalytic spot onto the growth orienting structure;

placing the substrate into an atmosphere of resonating member feedstock at a specified growth temperature for a time sufficient to allow for the oriented growth of at least one resonating member from the catalytic spot along the growth orienting structure such that at least one end of the resonating member is fixedly attached to the support structure, and such that at least a portion of the resonating member is free to oscillate.

65. A method of analyzing an frequency signal comprising the steps of:

providing at least one nanoresonator including a support structure, a tuning power source for producing a tuning bias, a bias detector, and at least one resonating member, wherein at least one portion of the resonating member is fixedly attached to the support structure and at least one portion of the member is free to oscillate at a resonant frequency, the resonating member in signal communication with the tuning power source such that a tuning bias applied to the resonating member alters the resonant frequency of the resonating member, the resonating member in further signal communication with the bias detector such that oscillatory motion of the resonating member induces a voltage or current measurable by the bias detector;

placing the nanoresonator into proximity of the frequency signal such that if the frequency of the frequency signal matches the resonant frequency of the resonating member the resonating member will undergo oscillatory motion; and

measuring the potential on the resonating member and communicating the potential to a user.

66. The method according to claim 65 wherein the potential is proportional to the motion of the nanoresonator.

67. The method according to claim 65 wherein the resonating member is a nanotube.

68. The method according to claim 67 wherein the method comprises providing at least two resonating members having different resonant frequencies.