Method of operating micromachined members coupled for relative rotation

• US 6,467,345 B1
• Filed: 03/03/2000
• Issued: 10/22/2002
• Est. Priority Date: 10/18/1993
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Xros, Inc. (Nortel Networks Corporation)
• Inventors: Slater, Timothy G., Neukermans, Armand P.
• Primary Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US09/518,364
• Time in Patent Office: 963 Days
• Field of Search: 735/040.2, 735/040.3, 735/040.4, 735/041.2
• US Class Current: 73/504.02
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129

Abstract

A method for operating a monolithic, integrated, micromachined structure that includes a reference member and one or more dynamic members. Each dynamic member is supported from the reference member, either directly or indirectly, by torsion hinges. Supported in this way, each dynamic member exhibits a plurality of vibrational modes. Preferably, the structure is micromachined to establishes specified relationships between various pairs of vibrational modes. The method also includes applying force to each dynamic member that urges the member to rotate out of a rest position to a fixed particular angle.

Claims

1. A method for operating an integrated, micromachined structure comprising the steps of:

providing a micromachined structure that is monolithically fabricated from a stress-free semiconductor layer of a silicon substrate, the micromachined structure including;

a reference member;

a first pair of torsion hinges projecting from the reference member; and

a first dynamic member that is coupled only by the first pair of torsion hinges to the reference member to be thereby supported from the reference member in a first rest position with respect to the reference member if no external force is applied to the first dynamic member;

the first pair of torsion hinges alone also supporting the first dynamic member for rotation about a first axis with respect to the reference member;

the first dynamic member as supported only by the first pair of torsion hinges exhibiting a plurality of vibrational modes with respect to the reference member including a principal torsional vibrational mode of rotation about the first axis, a vertical shaking vibrational mode, a vertical rocking vibrational mode, a lateral shaking vibrational mode, and a lateral rocking vibrational mode, each vibrational mode of the first dynamic member having a vibrational frequency; and

applying to the first dynamic member a first force that urges the first dynamic member to rotate about the first axis out of the first rest position to a fixed particular angle with respect to the reference member.

2. The method of claim 1 wherein the first dynamic member of the micromachined structure is provided with enhanced reflectivity by a thin layer of metal applied thereto.

3. The method of claim 2 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

4. The method of claim 3 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

5. The method of claim 3 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

6. The method of claim 2 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

7. The method of claim 6 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

8. The method of claim 6 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

9. The method of claim 1 wherein the first dynamic member of the micromachined structure is provided with enhanced reflectivity by a thin layer of dielectric applied thereto.

10. The method of claim 9 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

11. The method of claim 10 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

12. The method of claim 10 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

13. The method of claim 9 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

14. The method of claim 13 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

15. The method of claim 13 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

16. The method of claim 1 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

17. The method of claim 16 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

18. The method of claim 16 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

19. The method of claim 1 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

20. The method of claim 19 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

21. The method of claim 19 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

61. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the vertical shaking vibrational mode.

62. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the vertical rocking vibrational mode.

63. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the lateral shaking vibrational mode.

64. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the lateral rocking vibrational mode.

65. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of any other vibrational mode of the first dynamic member.

22. A method for operating an integrated, micromachined structure comprising the steps of:

providing a micromachined structure that is monolithically fabricated from a stress-free semiconductor layer of a silicon substrate, the micromachined structure including;

a reference member;

a first pair of torsion hinges projecting from the reference member; and

a first dynamic member that is coupled only by the first pair of torsion hinges to the reference member to be thereby supported from the reference member in a first rest position with respect to the reference member if no external force is applied to the first dynamic member;

the first pair of torsion hinges alone also supporting the first dynamic member for rotation about a first axis with respect to the reference member;

the first dynamic member as supported only by the first pair of torsion hinges exhibiting a plurality of vibrational modes with respect to the reference member including a principal torsional vibrational mode of rotation about the first axis, a vertical shaking vibrational mode, a vertical rocking vibrational mode, a lateral shaking vibrational mode, and a lateral rocking vibrational mode, each vibrational mode of the first dynamic member having a vibrational frequency;

the first dynamic member including;

a frame to which the first pair of torsion hinges couple;

a second pair of torsion hinges projecting from the frame, the second pair of torsion hinges being oriented non-parallel to the first pair of torsion hinges; and

a second dynamic member that is coupled only by the second pair of torsion hinges to the frame to be thereby supported from the frame in a second rest position with respect to the frame if no external force is applied to the second dynamic member;

the second pair of torsion hinges, the frame, and the first pair of torsion hinges alone also supporting the second dynamic member for rotation about a second axis with respect to the frame and about the first axis with respect to the reference member;

the second dynamic member as supported only by the second pair of torsion hinges, the frame, and the first pair of torsion hinges exhibiting a plurality of vibrational modes with respect to the frame including a principal torsional vibrational mode of rotation about the second axis, a vertical shaking vibrational mode, a vertical rocking vibrational mode, a lateral shaking vibrational mode, and a lateral rocking vibrational mode, each vibrational mode of the second dynamic member having a vibrational frequency;

applying to the first dynamic member a first force that urges the first dynamic member to rotate about the first axis out of the first rest position to a fixed particular angle with respect to the reference member; and

applying to the second dynamic member a second force that urges the second dynamic member to rotate about the second axis out of the second rest position to a fixed particular angle with respect to the frame.

23. The method of claim 22 wherein the second dynamic member of the micromachined structure is provided with enhanced reflectivity by a thin layer of metal applied thereto.

24. The method of claim 23 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

25. The method of claim 24 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

26. The method of claim 24 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

27. The method of claim 23 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

28. The method of claim 27 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

29. The method of claim 27 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by he capacitance sensor.

30. The method of claim 23 wherein the second force urging the second dynamic member to rotate is applied electrostatically.

31. The method of claim 30 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

32. The method of claim 30 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

33. The method of claim 23 wherein the second force urging the second dynamic-member to rotate is applied electromagnetically.

34. The method of claim 33 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

35. The method of claim 33 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

36. The method of claim 22 wherein the second dynamic member of the micromachined structure is provided with enhanced reflectivity by a thin layer of dielectric applied thereto.

37. The method of claim 36 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

38. The method of claim 37 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

39. The method of claim 37 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

40. The method of claim 36 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

41. The method of claim 40 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

42. The method of claim 40 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

43. The method of claim 36 wherein the second force urging the second dynamic member to rotate is applied electrostatically.

44. The method of claim 43 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

45. The method of claim 43 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

46. The method of claim 36 wherein the second force urging the second dynamic member to rotate is applied electromagnetically.

47. The method of claim 46 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

48. The method of claim 46 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

49. The method of claim 22 wherein the first force urging the first dynamic member to rotate is applied electrostatically.

50. The method of claim 49 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

51. The method of claim 49 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electrostatic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

52. The method of claim 22 wherein the first force urging the first dynamic member to rotate is applied electromagnetically.

53. The method of claim 52 wherein at least one of the torsion hinges of the first pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the torsion sensor.

54. The method of claim 52 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the first dynamic member with respect to the reference member;

and wherein a feedback loop used in applying the electromagnetic first force that urges the first dynamic member to rotate responds to the signal generated by the capacitance sensor.

55. The method of claim 22 wherein the second force urging the second dynamic member to rotate is applied electrostatically.

56. The method of claim 55 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

57. The method of claim 55 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electrostatic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

58. The method of claim 22 wherein the second force urging the second dynamic member to rotate is applied electromagnetically.

59. The method of claim 58 wherein at least one of the torsion hinges of the second pair provided in the micromachined structure includes a torsion sensor for generating a signal that measures angular deflection of the second dynamic member with respect to the frame;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the torsion sensor.

60. The method of claim 58 wherein the micromachined structure provided includes a capacitance sensor for generating a signal that measures angular deflection of the second dynamic member;

and wherein a feedback loop used in applying the electromagnetic second force that urges the second dynamic member to rotate responds to the signal generated by the capacitance sensor.

66. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the vertical shaking vibrational mode.

67. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the vertical rocking vibrational mode.

68. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the lateral shaking vibrational mode.

69. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of the lateral rocking vibrational mode.

70. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode is lower by at least 20% than the vibrational frequency of any other vibrational mode of the second dynamic member.

71. The method of claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 wherein, for the first dynamic member and second dynamic member of the micromachined structure provided, the vibrational frequency of the principal torsional vibrational mode of the first dynamic member is lower than the principal torsional vibrational mode of the second dynamic member.