Microelectromechanical system with non-collinear force compensation

• US 20030174422A1
• Filed: 03/12/2002
• Published: 09/18/2003
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Original Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Inventors: Rodgers, Murray Steven, Sniegowski, Jeffry Joseph, Miller, Samuel Lee, Barnes, Stephen Matthew, McWhorter, Paul Jackson
• Granted Patent: US 7,055,975 B2
• Time in Patent Office: Days
• US Class Current: 359/872
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 7/182 for mirrors
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

A microelectromechanical system is disclosed that constrains the direction of a force acting on a first load, where the force originates from the interaction of the first load and a second load. In particular, the direction of a force acting on the first load is caused to be substantially parallel with a motion of the first load. This force direction constraint is achieved by a force isolator microstructure that contains no rubbing or contacting surfaces. Various embodiments of structures/methods to achieve this force direction constraint using a force isolator microstructure are disclosed.

Claims

1. A microelectromechanical system, comprising:

a substrate;

a first load microstructure movably interconnected with said substrate for movement at least substantially along a first path;

a second load microstructure movably interconnected with said substrate;

a coupling assembly microstructure interconnecting said first and second load microstructures and that comprises means for transmitting a force that is exerted on said coupling assembly microstructure by at least one of said first and second load microstructures to achieve both first and second conditions, wherein said first condition is that said force is transmitted to said first load microstructure at least generally along said first path, and wherein said second condition is that no portion of said coupling assembly microstructure is deflected into contact with any other portion of said microelectromechanical system.

2. A microelectromechanical system, as claimed in claim 1, wherein:

said first load microstructure comprises an actuator microstructure.

3. A microelectromechanical system, as claimed in claim 1, wherein:

said first path is at least substantially linear.

4. A microelectromechanical system, as claimed in claim 1, wherein:

said first path is at least generally parallel with said substrate.

5. A microelectromechanical system, as claimed in claim 1, wherein:

said second load microstructure is selected from the group consisting essentially of a mirror microstructure, a lens, a diffraction element, and an attenuator.

6. A microelectromechanical system, as claimed in claim 1, wherein:

said first and second load microstructures are disposed at the same elevation within said microelectromechanical system.

7. A microelectromechanical system, as claimed in claim 1, wherein:

said first and second load microstructures are disposed at different elevations within said microelectromechanical system.

8. A microelectromechanical system, as claimed in claim 1, wherein:

a direction of said force at said second load microstructure is at least generally parallel with said first path.

9. A microelectromechanical system, as claimed in claim 8, wherein:

said first and second load microstructures are disposed at the same elevation in said microelectromechanical system.

10. A microelectromechanical system, as claimed in claim 8, wherein:

said first and second load microstructures are disposed at a different elevation in said microelectromechanical system.

11. A microelectromechanical system, as claimed in claim 1, wherein:

a direction of said force at said second load microstructure is other than parallel with said first path.

12. A microelectromechanical system, as claimed in claim 11, wherein:

said first and second load microstructures are disposed at the same elevation in said microelectromechanical system.

13. A microelectromechanical system, as claimed in claim 11, wherein:

said first and second load microstructures are disposed at a different elevation in said microelectromechanical system.

14. A microelectromechanical system, as claimed in claim 1, wherein:

said second load microstructure is movably interconnected with said substrate for movement at least substantially along a second path.

15. A microelectromechanical system, as claimed in claim 14, wherein:

said second path comprises a component that is at least substantially normal to said substrate.

16. A microelectromechanical system, as claimed in claim 14, wherein:

said second path comprises a component that is at least substantially parallel to said substrate.

17. A microelectromechanical system, as claimed in claim 14, wherein:

said second path is at least substantially linear.

18. A microelectromechanical system, as claimed in claim 14, wherein:

said second path is at least substantially arcuate.

19. A microelectromechanical system, as claimed in claim 14, wherein:

said first and second load microstructures are disposed at the same elevation in said microelectromechanical system and all movement of said first and second load microstructures along said first and second paths, respectively, is within a plane that is at least substantially parallel with said substrate.

20. A microelectromechanical system, as claimed in claim 14, wherein:

said second load microstructure is pivotally interconnected with said substrate such that a portion of said second load microstructure moves at least generally away from said substrate along an at least generally arcuate path.

21. A microelectromechanical system, as claimed in claim 14, wherein:

said first and second load microstructures are disposed at a different elevation in said microelectromechanical system.

22. A microelectromechanical system, as claimed in claim 21, wherein:

all movement of said first and second load microstructures along said first and second paths, respectively, is within a plane that is at least substantially parallel with said substrate.

23. A microelectromechanical system, as claimed in claim 1, wherein:

said coupling assembly microstructure comprises an elevator microstructure interconnected with said second load microstructure and a tether disposed between said elevator microstructure and said first actuator microstructure.

24. A microelectromechanical system, as claimed in claim 1, wherein:

said means for transmitting in relation to said first condition comprises a pivotless compliant microstructure, wherein said pivotless compliant microstructure comprises input and an output sections, wherein said input section is interconnected with said first load microstructure and said output section is interconnected with said second load microstructure.

25. A microelectromechanical system, as claimed in claim 24, wherein:

said pivotless compliant microstructure comprises a relief structure disposed between and interconnecting said pivotless compliant microstructure and said coupling assembly microstructure, wherein said means for transmitting in relation to said second condition further comprises said relief structure.

26. A microelectromechanical system, as claimed in claim 24, wherein:

said means for transmitting further in relation to said second condition comprises a frame assembly microstructure pivotally interconnected with said substrate, wherein said pivotless compliant microstructure is mounted on said frame assembly microstructure.

27. A microelectromechanical system, as claimed in claim 26, wherein:

said frame assembly microstructure is rigid and of one-piece construction.

28. A microelectromechanical system, as claimed in claim 26, wherein:

said frame assembly microstructure comprises a plurality of individual frame member microstructures that are each individually pivotally interconnected with said substrate, wherein each frame member microstructure is prestressed so as to move away from said substrate without an application of any external force to said frame member microstructure.

29. A microelectromechanical system, as claimed in claim 24, wherein:

said pivotless compliant microstructure is interconnected with said substrate by a first pivotable connection, wherein said means for transmitting in relation to said second condition comprises said first pivotable connection.

30. A microelectromechanical system, as claimed in claim 24, wherein:

said means for transmitting in relation to said second condition further comprises at least one cavity formed in said substrate under at least a portion of said pivotless compliant microstructure.

31. A microelectromechanical system, as claimed in claim 24, wherein:

said means for transmitting in relation to said second condition further comprises a cavity formed in said substrate, wherein an entirety of said pivotless compliant microstructure is disposed within said cavity.

32. A microelectromechanical system, as claimed in claim 24, wherein:

said pivotless compliant microstructure is anchored to said substrate at least at four anchor locations, wherein said means for transmitting in relation to said second condition comprises a location of at least two of said anchor locations.

33. A microelectromechanical system, as claimed in claim 1, wherein:

said means for transmitting comprises at least one doubly clamped beam.

34. A microelectromechanical system, as claimed in claim 33, wherein:

said at least one doubly clamped beam comprises a plurality of vertically spaced and rigidly interconnected structural layers.

35. A microelectromechanical system, as claimed in claim 1, wherein said means for transmitting in relation to said first condition comprises:

a pivotless compliant microstructure interconnected with said substrate and comprising input and output sections that are both movable relative to said substrate within a lateral dimension that is at least generally parallel with said substrate, wherein said second load microstructure is interconnected with said output section of said pivotless compliant microstructure and said input section of said pivotless compliant microstructure is interconnected with said first load microstructure, wherein a movement of said first load microstructure relative to said substrate along said first path displaces said input section of said pivotless complaint microstructure a first distance within said lateral dimension, and that in turn displaces said output section of said pivotless complains microstructure a second distance in said lateral dimension, wherein said first and second distances are selected from the group consisting essentially of equal and unequal magnitudes.

36. A microelectromechanical system, as claimed in claim 35, wherein:

said output section is formed from a single structural layer by surface micromachining and a remainder of said pivotless compliant microstructure is formed from at least two vertically spaced structural layers by surface micromachining and that are anchored to each other at a plurality of locations.

37. A microelectromechanical system, as claimed in claim 35, wherein:

a configuration of said output section and how said output section interconnects with a remainder of said pivotless compliant microstructure comprises said means for transmitting in relation to said second condition.

38. A microelectromechanical system, as claimed in claim 35, wherein:

said pivotless compliant microstructure comprises first and second beam microstructures that are attached to said output section of said pivotless compliant microstructure at a first location, and further extend away from said output section of said pivotless compliant microstructure in at least generally opposite directions, wherein said output section comprises first and second ends, and wherein said first location is disposed at an intermediate location between said first and second ends.

39. A microelectromechanical system, as claimed in claim 35, wherein:

said pivotless compliant microstructure comprises first and second beam microstructures that are attached to said output section of said pivotless compliant microstructure at a first longitudinal location, and further extend away from said output section of said pivotless compliant microstructure in at least generally opposite directions, wherein said output section extends from said first longitudinal location at least generally toward but not to said input section of said pivotless compliant microstructure.

40. A microelectromechanical system, as claimed in claim 35, wherein:

said means for transmitting in relation to said second condition comprises a rigid frame microstructure pivotally interconnected with said substrate and said pivotless compliant microstructure being mounted on said frame microstructure.

41. A microelectromechanical system, as claimed in claim 40, wherein:

said pivotless compliant microstructure comprises a first portion of said coupling assembly microstructure, wherein a second portion of said coupling assembly microstructure is disposed between said input section of said pivotless compliant microstructure and said first load microstructure, and wherein said means for transmitting in relation to said first condition comprises at lease one doubly clamped beam that is attached to said second portion of said coupling assembly microstructure and that is anchored to said substrate on opposite sides of second portion of said coupling assembly microstructure.

42. A microelectromechanical system, as claimed in claim 35, wherein:

said means for transmitting in relation to said second condition comprises a plurality of prestressed elevation member microstructures pivotally interconnected with said substrate with said pivotless compliant microstructure being mounted on said plurality of prestressed elevation member microstructures.

43. A microelectromechanical system, as claimed in claim 42, wherein:

said pivotless compliant microstructure comprises a first portion of said coupling assembly microstructure, wherein a second portion of said coupling assembly microstructure is disposed between said input section of said pivotless compliant microstructure and said first load microstructure, and wherein said means for transmitting in relation to said first condition comprises at lease one doubly clamped beam that is attached to said second portion of said coupling assembly microstructure and that is anchored to said substrate on opposite sides of second portion of said coupling assembly microstructure.

44. A microelectromechanical system, as claimed in claim 35, wherein:

said means for transmitting in relation to said second condition comprises said pivotless compliant microstructure being interconnected with said substrate at only first and second locations, wherein said pivotless compliant microstructure is pivotally interconnected with said substrate at said first and second locations.

45. A microelectromechanical system, as claimed in claim 44, wherein:

said pivotless compliant microstructure comprises a first portion of said coupling assembly microstructure, wherein a second portion of said coupling assembly microstructure is disposed between said input section of said pivotless compliant microstructure and said first load microstructure, and wherein said means for transmitting in relation to said first condition comprises at lease one doubly clamped beam that is attached to said second portion of said coupling assembly microstructure and that is anchored to said substrate on opposite sides of second portion of said coupling assembly microstructure.

46. A microelectromechanical system, as claimed in claim 35, wherein:

said means for transmitting in relation to said second condition comprises first and second cavities formed in said substrate on opposite sides of a reference axis that extends between said input and output sections of said pivotless compliant microstructure, wherein first and second lateral extremes of said pivotless compliant microstructure are disposed above said first and second cavities, respectively.

47. A microelectromechanical system, as claimed in claim 35, wherein:

said pivotless compliant microstructure is disposed in spaced relation to said substrate and is anchored to said substrate at first and second locations, wherein said first and second anchor locations are disposed on opposite sides of a reference axis that extends between said input and output sections of said pivotless compliant microstructure and that defines a longitudinal dimension whereby said first and second anchor locations are laterally spaced, wherein said pivotless compliant microstructure further comprises first and second lateral extremes that are disposed on opposite sides of said reference axis, wherein said first and second anchor locations are disposed at a longitudinal position from said output section that is at least as great as a longitudinal position of said first and second lateral extremes, wherein said means for transmitting in relation to said second condition comprises a position of said first and second anchor locations relative to said first and second lateral extremes.

48. A microelectromechanical system, as claimed in claim 35, wherein:

said means for transmitting in relation to said second condition comprises a cavity in said substrate, wherein at least a substantial portion of said pivotless compliant microstructure is disposed within said cavity.

49. A microelectromechanical system, comprising:

a substrate;

a first load microstructure movably interconnected with said substrate for movement along a first path that is at least generally parallel with said substrate;

a second load microstructure movably interconnected with said substrate;

a force isolator microstructure interconnected with said substrate;

a first coupling microstructure allowing a first force to be transmitted between said force isolator microstructure and said first load microstructure, wherein said first force is in a direction that is at least generally collinear with a motion of said first load microstructure along said first path; and

a second coupling microstructure allowing a second force to be transmitted between said force isolator microstructure and said second load microstructure, wherein said first and second forces are non-collinear, wherein a third force exerted on said force isolator microstructure is a resultant of said first and second forces, wherein said force isolator microstructure is configured such that no surfaces of said force isolator microstructure are deflected into contact with any other portion of said microelectromechanical system during normal operation of said microelectromechanical system and including upon exposure to said third force.

50. A microelectromechanical system, as claimed in claim 49, wherein:

said force isolator microstructure comprises means for redirecting at least a portion of said second force so as to be applied to said first load microstructure in a manner so as to be at least generally collinear with said first force.

51. A microelectromechanical system, as claimed in claim 49, wherein:

said force isolator microstructure comprises means for restraining an application of a vertical force component from said second force to said first load microstructure.

52. A microelectromechanical system, as claimed in claim 49, wherein:

said force isolator microstructure is selected from the group consisting essentially of a pivotless compliant microstructure, a spacing between at least a portion of said pivotless compliant microstructure and said substrate, how said pivotless compliant microstructure is interconnected with said substrate, how said second coupling assembly microstructure interconnects with said pivotless compliant microstructure, at least one doubly clamped beam that is attached to said first coupling assembly microstructure and anchored to said substrate on opposite sides of said first coupling assembly microstructure, and any combination thereof.

53. A method for operating a microelectromechanical system that comprises first and second load microstructures and a coupling assembly microstructure that is disposed between and that interconnects said first and second load microstructures, said method comprising the steps of:

moving said first load microstructure relative to said substrate at least generally along a first path;

moving said second load microstructure relative to said substrate at least substantially along a second path, wherein said moving said second load microstructure step exerts a force on said coupling microstructure having a vector that is disposed in non-collinear relation to said first path;

configuring said microelectromechanical system to preclude any portion of said coupling microstructure from deflecting into contact with any other portion of said microelectromechanical system due to said moving said second load microstructure step; and

redirecting said force prior to reaching said first load microstructure so as be at least substantially directed along said first path.

54. A method, as claimed in claim 53, wherein:

said moving said first load microstructure step comprises moving said first load microstructure relative to said substrate along an at least substantially linear said first path.

55. A method, as claimed in claim 53, wherein:

said moving said first load microstructure step comprises moving said first load microstructure relative to said substrate in at least substantially parallel relation to said substrate.

56. A method, as claimed in claim 53, wherein:

said moving said second load microstructure step is responsive to said moving said first load microstructure step.

57. A method, as claimed in claim 53, wherein:

said moving said first load microstructure step and said moving said second load microstructure step are each executed at a first elevation within said microelectromechanical system.

58. A method, as claimed in claim 57, wherein:

said moving said first load microstructure step and said moving said second load microstructure step are executed along at least generally parallel paths.

59. A method, as claimed in claim 53, wherein:

said moving said first load microstructure step is executed at a first elevation within said microelectromechanical system and said moving said second load microstructure step is executed a second elevation within said microelectromechanical system that is different from said first elevation.

60. A method, as claimed in claim 53, wherein:

said moving said second load microstructure step comprises moving said second load microstructure along an at least substantially linear path.

61. A method, as claimed in claim 53, wherein:

said moving said second load microstructure step comprises pivoting said second load microstructure relative to said substrate.

62. A method, as claimed in claim 53, wherein:

said moving said second load microstructure step comprises moving said second load microstructure along an at least generally arcuate path.

63. A method, as claimed in claim 53, wherein:

said coupling assembly microstructure comprises a pivotless compliant microstructure interconnected with said substrate and comprising input and output sections that are both movable relative to said substrate within a lateral dimension that is at least generally parallel with said substrate, wherein said second load microstructure is interconnected with said output section of said pivotless compliant microstructure and said input section of said pivotless compliant microstructure is interconnected with said first load microstructure, wherein said moving said first load microstructure step displaces said input section of said pivotless compliant microstructure a first distance within said lateral dimension, and that in turn displaces said output section of said first displacement multiplier microstructure a second distance in said lateral dimension, wherein said first and second distances are selected from the group consisting of equal and unequal magnitudes.

64. A method, as claimed in claim 63, wherein:

said configuring step comprises selecting a manner of interconnecting said second load microstructure with said pivotless compliant microstructure.

65. A method, as claimed in claim 63, wherein:

said configuring step comprises mounting said pivotless compliant microstructure on a rigid frame that is pivotally interconnected with said substrate.

66. A method, as claimed in claim 63, wherein:

said configuring step comprises mounting said pivotless compliant microstructure on a plurality of pre-stressed elevation member microstructures.

67. A method, as claimed in claim 63, wherein:

said configuring step comprises mounting said pivotless compliant microstructure on a plurality of compliant members that are pivotally interconnected with said substrate and that are at least generally arcuately shaped extending away from said substrate.

68. A method, as claimed in claim 63, wherein:

said configuring step comprises pivotally interconnecting said pivotless compliant microstructure with said substrate.

69. A method, as claimed in claim 63, wherein:

said configuring step comprises providing a sufficient spacing between at least the portion of said pivotless compliant microstructure and said substrate.

70. A method, as claimed in claim 63, wherein:

said configuring step comprises providing a sufficient spacing between an entirety of said pivotless compliant microstructure and said substrate.

71. A method, as claimed in claim 63, wherein:

said configuring step comprises selecting appropriate anchor locations for said pivotless compliant microstructure to said substrate.

72. A method, as claimed in claim 53, wherein:

said redirecting step comprises disposing a pivotless compliant microstructure between said first load microstructure and said second load microstructure, wherein said pivotless compliant microstructure is part of said coupling assembly microstructure.

73. A method, as claimed in claim 53, wherein:

said redirecting step comprises restraining motion of at least the portion of said coupling assembly microstructure away from said substrate.

74. A method, as claimed in claim 73, wherein:

said restraining step comprises using at least one doubly clamped beam that is attached to a first part of said coupling assembly microstructure and that is anchored to said substrate on opposite sides of said first part of said coupling assembly microstructure.