COMPLIANT PUSH/PULL CONNECTOR MICROSTRUCTURE

• US 20030174931A1
• Filed: 03/14/2002
• Published: 09/18/2003
• Est. Priority Date: 03/14/2002
• Status: Active Grant

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Inventors: Rodgers, Murray Steven, Miller, Samuel Lee, Barnes, Stephen Matthew
• Granted Patent: US 6,650,806 B2
• Time in Patent Office: Days
• US Class Current: 385/18
• CPC Class Codes: B81B 3/0062 Devices moving in two or more dimensions, i.e. having special features which allow movement in more than one dimension
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams

Abstract

A microelectromechanical system is disclosed that has a connector (444) between an elongate coupling/tether (400) and an elevation structure (382) that is movably interconnected with an appropriate substrate (380). A first free end (392) of the elevation structure (382) moves at least generally away from or toward the substrate (380), depending upon the direction of motion of an actuator assembly (464) that is appropriately interconnected with the tether (400). Part of the connector (444) is in compression and another part of the connector (444) is in tension, regardless of whether a pulling or pushing force is being exerted on the tether (400), and thereby the connector (444), by the actuator assembly (464).

Claims

1. A microelectromechanical system that comprises:

a substrate;

a lever assembly movably interconnected with said substrate at a first location and comprising a first free lever end that is displaced from said first location and moveable at least generally away from said substrate;

an actuator assembly interconnected with said substrate for movement along a first path;

a coupling interconnected with said actuator assembly; and

a connector attached to said lever assembly and comprising first and second flex link assemblies and first and second connector ends, wherein said second connector end is located between said first connector end and said actuator assembly, wherein said coupling is attached to said first connector end, wherein said first and second flex link assemblies extend between and interconnect said first and second connector ends, and wherein said connector further comprises a first interconnect that extends between and interconnects said first flex link assembly and a first portion of said lever assembly, as well as a second interconnect that extends between and interconnects said second flex link assembly and a second portion of said lever assembly.

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

said lever assembly comprises first and second laterally spaced levers and a cross beam that extends between and interconnects said first and second levers at a location such that said connector is located between said cross beam and where said first and second levers are movably interconnected with said substrate.

3. A system, as claimed in claim 2, wherein:

said cross beam attaches to first and second free lever ends of said first and second levers, respectively.

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

said actuator assembly comprises at least one actuator.

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

said coupling is also attached to said second connector end.

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

each of said first and second connector ends are attached to both said first and second flex link assemblies.

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

said first and second connector ends and said first and second flex link assemblies collectively define an at least generally rectangular frame having a closed perimeter.

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

said first and second flex link assemblies are disposed in at least generally parallel relation with said coupling, and wherein said first and second connector ends are disposed in at least generally perpendicular relation to said first and second flex link assemblies and said coupling.

9. A system, as claimed in claim 1, wherein:

said connector is a continuous structure of one-piece construction.

10. A system, as claimed in claim 1, wherein:

said connector is formed from a single structural layer by surface micromachining.

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

said first and second levers, as well as said connector, are each formed in a first structural layer by surface micromachining.

12. A system, as claimed in claim 1, wherein:

said first and second levers are each formed in a first structural layer by surface micromachining, and wherein said connector is formed in a second structural layer by surface micromachining that is vertically spaced from said first structural layer.

13. A system, as claimed in claim 1, wherein:

said first and second interconnects are disposed along a common axis.

14. A system, as claimed in claim 13, wherein:

said common axis is at least generally transverse to said coupling.

15. A system, as claimed in claim 1, wherein:

said first and second interconnects are disposed at least generally at a midpoint between said first and second connector ends.

16. A system, as claimed in claim 1, wherein:

said actuator moves along said first path in first and second directions, wherein said coupling is in tension when said actuator assembly moves in said first direction, wherein said coupling is in compression when said actuator assembly moves in said second direction, wherein a first part of each of said first and second flex link assemblies is in compression and a second part of each of said first and second flex link assemblies is in tension when said actuator assembly moves in said first direction, and wherein said first part of each of said first and second flex link assemblies is in tension and said second part of each of said first and second flex link assemblies is in compression when said actuator assembly moves in said second direction.

17. A system, as claimed in claim 16, wherein:

said first part of each of said first and second flex link assemblies is that portion of said first and second connector sides that extends between said first connector end and said first and second interconnects, respectively, and wherein said second part of each of said first and second flex link assemblies is that portion of said first and second flex link assemblies that extends between said second connector end and said first and second interconnects, respectively.

18. A system, as claimed in claim 1, wherein:

said actuator assembly generates both an actuating force and a restoring force to move said first and second free lever ends away from and back toward said substrate, respectively, by a movement of said actuator assembly along said first path, wherein a buckle strength of said coupling between opposite ends of said coupling is greater than a maximum magnitude of a component of said restoring force that is along said first path.

19. A system, as claimed in claim 18, wherein:

said actuator assembly moves in a first direction along said first path to exert said actuating force on said coupling, and moves in a second direction along said first path to exert said restoring force on said coupling, said first direction being opposite said second direction.

20. A system, as claimed in claim 18, wherein:

said coupling has a length of at least about 750 microns.

21. A system, as claimed in claim 18, wherein:

said coupling comprises first and second structural layers that are disposed in spaced relation and rigidly interconnected at a plurality of locations between said opposite ends of said coupling.

22. A system, as claimed in claim 18, wherein:

a movement of said first free lever end back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

23. A system, as claimed in claim 18, wherein:

a speed at which said first free lever end moves back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

24. A system, as claimed in claim 18, wherein:

an acceleration of said first free lever end back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

25. A system, as claimed in claim 18, wherein:

said stiffness of said coupling is such that said coupling undergoes at least substantially no elastic deformation when actuator assembly exerts said restoring force on said coupling.

26. A system, as claimed in claim 18, wherein:

said component of said restoring force that is along said first path is at least about 20 μ

N.

27. A system, as claimed in claim 18, further comprising:

a mirror interconnected with a portion of said lever assembly that is movable relative to said substrate.

28. A system, as claimed in claim 1, wherein:

said coupling comprises first and second structural layers that are disposed in spaced relation and interconnected, and wherein said actuator generates both an actuating force and a restoring force to move said first free lever end away from and back toward said substrate, respectively, by a movement of said actuator assembly along said first path.

29. A system, as claimed in claim 28, wherein:

said actuator assembly moves in a first direction along said first path to exert said actuating force on said coupling, and moves in a second direction along said first path to exert said restoring force on said coupling, said first direction being opposite said second direction.

30. A system, as claimed in claim 28, wherein:

said elongate coupling has a length of at least about 750 microns.

31. A system, as claimed in claim 28, wherein:

a buckle strength of said coupling between said opposite ends of said coupling is greater than a maximum magnitude of a component of said restoring force that is directed along said first path.

32. A system, as claimed in claim 31, wherein:

a movement of said first free lever end back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

33. A system, as claimed in claim 31, wherein:

a speed at which said first free lever end moves back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

34. A system, as claimed in claim 31, wherein:

an acceleration of said first lever end back toward said substrate by said actuator assembly exerting said restoring force on said coupling is at least substantially solely controlled by external forces that are exerted on said coupling.

35. A system, as claimed in claim 31, wherein:

said buckle strength of said coupling is such that said coupling undergoes at least substantially no elastic deformation when actuator assembly exerts said restoring force on said coupling.

36. A system, as claimed in claim 31, wherein:

said component of said restoring force that is along said first path is at least about 20 μ

N.

37. A microelectromechanical system that comprises:

a substrate;

a lever assembly movably interconnected with said substrate at a first location and comprising a first free lever end that is displaced from said first location and moveable at least generally away from said substrate;

an actuator assembly interconnected with said substrate for movement along a first path;

a coupling interconnected with said actuator assembly; and

a connector disposed between and attached to each of said coupling and said lever assembly such that a first part of said connector is in compression and a second part of said connector is in tension when said actuator assembly moves in a first direction along said first path and exerts a tensile force on said coupling, and further such that said first part is in tension and said second part is in compression when said actuator assembly moves in a second direction along said first path and exerts a compressive force on said coupling.

38. A system, as claimed in claim 37, wherein:

said connector comprises a frame having a closed perimeter, a first interconnect extending from one side of said frame and attached to a first portion of said lever assembly, and a second interconnect extending from an opposite side of said frame and attached to a second portion of said lever assembly.

39. A system, as claimed in claim 38, wherein:

said second part is a portion of said frame that extends at least generally toward said actuator assembly from where said first and second interconnects merge with said frame, and wherein said first part is a portion of said frame that extends at least generally away from said actuator assembly from where said first and second interconnects merge with said frame.

40. A system, as claimed in claim 38, wherein:

said second part is a portion of said frame that extends in a third direction from where said first and second interconnects merge with said frame, and wherein said first part is a portion of said frame that extends in a fourth direction that is at least generally opposite said third direction from said first and second interconnects merge with said frame.

41. A system, as claimed in either of claims 39 or 40, wherein:

said frame comprises first and second frame ends that are spaced in a direction in which said coupling at least generally extends, wherein said second frame end is located between said actuator assembly and said first frame end, wherein said coupling is attached to at least said first frame end, wherein said first part comprises first and second flex links that are disposed on opposite sides of said coupling and that are disposed between said first frame end and where said first and second interconnects merge with said frame, and wherein said second part comprises third and fourth flex links that are disposed on opposite sides of said coupling and that are disposed between said second frame end and where said first and second interconnects merge with said frame.

42. A system, as claimed in claim 37, wherein:

said connector comprises a plurality of interconnected flex links, wherein said first part comprises at least two of said plurality of said flex links, and wherein said second part comprises at least another two of said plurality of said flex links.

43. A system, as claimed in claim 37, wherein:

said connector comprises first, second, third, and fourth flex links, wherein said first part comprises said first and second flex links, and wherein said second part comprises said third and fourth flex links.

44. A system, as claimed in claim 43, wherein:

said connector comprises a frame, wherein said frame comprises said plurality of flex links and first and second frame ends that are spaced in a direction in which said coupling at least generally extends, wherein said second frame end is located between said actuator assembly and said first frame end, wherein said coupling is attached to at least said first frame end, wherein said first and second flex links are disposed on opposite sides of said coupling and further are disposed between said first frame end and where said first and second interconnects merge with said frame, and wherein third and fourth flex links are disposed on opposite sides of said coupling and further and are disposed between said second frame end and where said first and second interconnects merge with said frame.

45. A method for simultaneously moving a lever assembly of a microelectromechanical system, wherein said method comprises the steps of:

pulling on a connector attached to said lever assembly;

executing a first moving step comprising moving said lever assembly at least 5 generally away from a substrate in response to said pulling step;

placing a first portion of said connector in compression by said pulling step;

placing a second portion of said connector in tension by said pulling step;

pushing on said connector;

executing a second moving step comprising moving said lever assembly at least generally toward said substrate in response to said pushing step;

placing said first portion of said connector in tension by said pushing step; and

placing said second portion of said connector in compression by said pushing step.

46. A method, as claimed in claim 45, wherein:

said microelectromechanical system comprises a coupling attached to said connector, wherein said method further comprises the steps of said pulling on said coupling and pushing on said coupling, wherein said pulling on said connector step is responsive to said pulling on said coupling step, and wherein said pushing on said connector step is responsive to said pushing on said coupling step, wherein said executing a second moving step is at least substantially solely controlled by external forces that are exerted on said coupling during said pushing on said coupling step.

47. A method, as claimed in claim 46, wherein:

said pulling on said coupling step comprises moving an actuator assembly microstructure relative to said substrate, wherein said actuator assembly microstructure comprises at least one actuator microstructure.

48. A method, as claimed in claim 46, wherein:

said executing a first moving step comprises moving a free end of said lever assembly along an at least generally arcuate path.

49. A method, as claimed in claim 46, wherein:

said executing a first moving step is within a first reference plane that is at least substantially perpendicular to a general lateral extent of said substrate.

50. A method, as claimed in claim 46, wherein:

said executing a first moving step is within a first reference plane that is disposed other than in perpendicular relation to a general lateral extent of said substrate.

51. A method, as claimed in claim 46, wherein:

said pushing on said coupling step comprises exerting a force on said coupling having a component in an x direction of at least about 20 μ

N, wherein said x direction is parallel with a general lateral extent of said substrate.

52. A method, as claimed in claim 46, wherein:

said pulling on said coupling step comprises moving an actuator assembly in a first direction, and wherein said pushing on said coupling step comprises moving said actuator assembly in a second direction that is opposite said first direction.

53. A method, as claimed in claim 46, wherein:

said executing a second moving step comprises forming said coupling with a buckle strength between first and second coupling ends of said coupling that is greater than a maximum magnitude of a component of a force in an x direction that is exerted on said coupling by said pushing on said coupling step, wherein said x direction is parallel with a general lateral extent of said substrate.

54. A method, as claimed in claim 46, wherein:

said executing a second moving step comprises at least substantially precluding flexure between opposite ends of said coupling during said pushing on said coupling step.

55. A method, as claimed in claim 46, further comprising the step of:

using said pulling and pushing on said coupling steps to move a mirror microstructure relative to said substrate.