Microelectromechnical system for tilting a platform

• US 6,794,793 B2
• Filed: 09/27/2001
• Issued: 09/21/2004
• Est. Priority Date: 09/27/2001
• Status: Expired due to Term

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Inventors: Miller, Samuel Lee, Rodgers, Murray Steven, Barnes, Stephen Matthew, Sniegowski, Jeffry Joseph, McWhorter, Paul Jackson
• Primary Examiner(s): TAMAI, KARL I
• Application Number:
  US09/966,963
• Publication Number:
  US 20030057350A1
• Time in Patent Office: 1,090 Days
• Field of Search: 310/309, 385/16, 385/18, 359/223, 359/224, 359/290, 359/291, 359/871, 359/872
• US Class Current: 310/309
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• 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: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H02N 1/008 Laterally driven motors, e.g. of the comb-drive type

Abstract

The present invention provides a MEM system (10) having a platform (14) that is both elevatable from the substrate (12) on which it is fabricated and tiltable with one, two or more degrees of freedom with respect to the substrate (12). In one embodiment, the MEM system (10) includes the platform (14), a pair of A-frame structures (40), and two pairs of actuators (30) formed on the substrate (12). Ends (46A) of rigid members (46) extending from apexes (40A) of the A-frame structures (40) are attached to the platform (14) by compliant members (48A, 48B). The platform (14) is also attached to the substrate (12) by a compliant member (48C). The A-frame structures (40) are separately pivotable about bases (40B) thereof. Each pair of actuators (30) is coupled through a yoke (32) and displacement multiplier (34) to one of the A-frame structures (40) and is separately operable to effect pivoting of the A-frame structures (40) with respect to the substrate (12) by equal or unequal angular amounts. Upon pivoting, the A-frame structures (40) act as lever arms to both lift the platform (14) and tilt the platform (14) with respect to the substrate (12) with at least one degree of freedom. Since the platform (14) lifts up from the surface of the substrate (12), it may be tilted at large angles with respect to the substrate (12).

Claims

1. A microelectromechanical system comprising:

a substrate;

a platform including first, second and third attachment points, said platform being pivotably attached to said substrate at the first attachment point;

a first lever arm attached to said platform at the second attachment point of said platform and pivotably attached to said substrate at a first anchor point on said substrate; and

a second lever arm attached to said platform at the third attachment point of said platform and pivotably attached to said substrate at a second anchor point on said substrate;

said first attachment paint being located on the some side of a line intersecting said second and third attachment points as a side of said line on which said first and second anchor points are located when said platform is in a non-tilted orientation with respect to said substrate;

said first and second lever arms being separately pivotable about said first and second anchor points, respectively, by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees of freedom, wherein each of said first and second lever arms are pivotable in response to an actuation force mechanically coupled thereto and generated without utilizing any portion of said lever arms and said platform.

2. The system of claim 1 further comprising:

a first actuator microstructure formed on said substrate, said first actuator microstructure being coupled to said first lever arm and operable to effect pivoting of said first lever arm with respect to said substrate; and

a second actuator microstructure formed on said substrate, said second actuator microstructure being coupled to said second lever arm and operable to effect pivoting of said second lever arm with respect to said substrate.

3. The system of claim 2 wherein said first and second actuator microstructures are separately operable without external feedback control to effect pivoting of said first and second lever arms, respectively, with respect to said substrate such that said platform is inclinable in a first direction with respect to said substrate at any angle within a first specified range of angles and inclinable in a second direction with respect to said substrate at any angle within a second specified range of angles.

4. The system of claim 3 wherein the first specified range of angles is between 0 and 60 degrees and said second range of angles is between −

45 and +45 degrees.

5. The system of claim 3 wherein said first and second actuator microstructures comprise electrostatic actuators operable in response to control voltages applied across terminals thereof.

6. The system of claim 4 wherein said platform is tiltable with respect to said substrate with one degree of freedom by applying the same level control voltage across terminals of said first and second actuator microstructures.

7. The system of claim 2 further comprising:

a first tether coupling a laterally moveable output of said first actuator microstructure to said first lever arm; and

a second tether coupling a laterally moveable output of said second actuator microstructure to said second lever arm.

8. The system of claim 7 wherein said first and second actuator microstructures are respectively comprised of first and second groups of separate actuators having separate laterally moveable outputs, and said system further comprises:

a first yoke joining said laterally moveable outputs of said first group of actuators together for connection with said first tether; and

a second yoke joining said laterally moveable outputs of said second group of actuators together for connection with said second tether.

9. The system of claim 8 further comprising:

a first displacement multiplier coupling said first tether to said first yoke; and

a second displacement multiplier coupling said second tether to said second yoke.

10. The system of claim 1 wherein said substrate comprises silicon.

11. The system of claim 1 wherein said platform comprises one of monocrystalline and polycrystalline silicon.

12. The system of claim 1 wherein said platform includes at least one of an optically reflective surface, a diffraction grating, a lens, and an optical polarizer.

13. The system of claim 1 further comprising:

a first compliant member attaching said platform to said substrate at the first attachment point;

a second compliant member attaching said first lever arm to said platform at the second attachment point; and

a third compliant member attaching said second lever arm to said platform at the third attachment point.

14. The system of claim 13 wherein said first, second and third compliant members comprise springs.

15. The system of claim 1 wherein said first and second lever arms have different lengths measured between where each said lever arm is attached to said substrate and to said platform.

16. A microelectromechanical system comprising:

a substrate;

a platform;

a first lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a first anchor point on said substrate; and

a second lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a second anchor point on said substrate;

said first and second lever arms being pivotable about said first and second anchor points, respectively, in at least a first direction by equal angular amounts to tilt said platform with one degree of freedom in at least the first direction;

said first and second lever arm being pivotable about said first and second anchor points, respectively, in at least a first direction by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees of freedom; and

wherein each of said first and second lever arms are pivotable in response to an actuation force mechanically coupled thereto and generated without utilizing any portion of said lever arms and said platform.

17. The system of claim 16 further comprising:

a first actuator microstructure formed on said substrata, said first actuator microstructure being coupled to said first lever arm and operable to effect pivoting of said first lever arm with respect to said substrata; and

a second actuator microstructure formed on said substrate, said second actuator microstructure being coupled to said second lever arm and operable to effect pivoting of said second lever arm with respect to said substrate.

18. The system of claim 17 wherein said first and second actuator microstructures are separately operable without external feedback control to effect pivoting of said first and second lever arms, respectively, with respect to said substrate such that said platform is inclinable in a first direction with respect to said substrate at any angle within a first specified range of angles and inclinable in a second direction with respect to said substrate at any angle within a second specified range of angles.

19. The system of claim 18 wherein the first specified range of angles is between 0 and 60 degrees and said second range of angles is between −

45 and +45 degrees.

20. The system of claim 17 wherein said first and second actuator microstructures comprise electrostatic actuators operable in response to control voltages applied across terminals thereof.

21. The system of claim 20 wherein said platform is tiltable wish respect to said substrate with one degree of freedom by applying the same level control voltage across terminals of said first and second actuator microstructures.

22. The system of claim 17 further comprising:

a first tether coupling a laterally moveable output of said first actuator microstructure to said first lever arm; and

a second tether coupling a laterally moveable output of said second actuator microstructure to said second lever arm.

23. The system of claim 17 wherein said first and second actuator microstructures are respectively comprised of first and second groups of separate actuators having separate laterally moveable outputs, and said system further comprises:

a first yoke joining said laterally moveable outputs of said first group of actuators together for connection with said first tether; and

a second yoke joining said laterally moveable outputs of said second group of actuators together for connection, with said second tether.

24. The system of claim 23 further comprising:

a first displacement multiplier coupling said first tether to said first yoke; and

a second displacement multiplier coupling said second tether to said second yoke.

25. The system of claim 16 wherein said substrate comprises silicon.

26. The system of claim 16 wherein said platform comprises one of monocrystalline and polycrystalline silicon.

27. The system of claim 16 wherein said platform includes at least one of an optically reflective surface, a diffraction grating, a lens, and an optical polarizer.

28. The system of claim 16 wherein said compliant members comprise springs.

29. The system of claim 16 wherein said first and second lever arms have different lengths measured between where each said lever arm is attached to said substrate and to said platform.

30. A microelectromechanical system comprising:

a substrate;

a platform including first, second and third attachment points, said platform being pivotably attached to said substrate at the first attachment point;

a first lever arm attached to said platform at the second attachment point of said platform and pivotably attached to said substrate at a first anchor point on said substrate;

a second lever arm attached to said platform at the third attachment point of said platform and pivotably attached to said substrate at a second anchor point on said substrate;

a first actuator microstructure formed on said substrate, said first actuator microstructure being coupled to said first lever arm and operable to effect pivoting of said first lever arm with respect to said substrate;

a second actuator microstructure formed on said substrate, said second actuator microstructure being coupled to said second lever arm and operable to effect pivoting of said second lever arm with respect to said substrate;

a first tether coupling a laterally moveable output of said first actuator microstructure to said first lover arm; and

a second tether coupling a laterally moveable output of said second actuator microstructure to said second lever arm;

said first attachment point being located on the same side of a line intersecting said second and third attachment points as a side of said line on which said first and second anchor points arm located when said platform is in a non-tilted orientation with respect to said substrate;

said first and second lever inns being separately pivotable about said first and second anchor points, respectively, by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees of freedom.

31. The system of claim 30 wherein said first and second actuator microstructures are respectively comprised of first and second groups of separate actuators having separate laterally moveable outputs, and said system further comprises:

a first yoke joining said laterally moveable outputs of said first group of actuators together for connection with said first tether; and

a second yoke joining said laterally moveable outputs of said second group of actuators together for connection with said second tether.

32. The system of claim 31 further comprising:

a first displacement multiplier coupling said first tether to said first yoke; and

a second displacement multiplier coupling said second tether to said second yoke.

33. A microelectromechanical system comprising:

a substrate;

a platform including first, second and third attachment points, said platform being pivotably attached to said substrate at the first attachment point;

a first lever arm attached to said platform at the second attachment point of said platform and pivotably attached to said substrate at a first anchor point on said substrate; and

a second lever arm attached to said platform at the third attachment point of said platform and pivotably attached to said substrate at a second anchor point on said substrate;

said first attachment point being located on the same side of a line intersecting said second and third attachment points as a side of said line on which said first and second anchor points are located when said platform is in a non-tilted orientation with respect to said substrate;

said first and second lever arms being separately pivotable about said first and second anchor points, respectively, by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees at freedom; and

wherein said first and second lever arm, have different lengths measured between where each said lever arm is attached to said substrate and to said platform.

34. A microelectromechanical system comprising:

a substrate;

a platform;

a first lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a first anchor point on said substrate;

a second lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a second anchor point on said substrate;

a first actuator microstructure formed on said substrate, said first actuator microstructure being coupled to said first lever arm and operable to effect pivoting of said first lever arm with respect to said substrate;

a second actuator microstructure formed on said substrate, said second actuator microstructure being coupled to said second lever arm and operable to effect pivoting of said second lever arm with respect to said substrate;

a first tether coupling a laterally moveable output of said first actuator microstructure to said first lever arm; and

a second tether coupling a laterally moveable output of said second actuator microstructure to said second lever arm;

said first and second lever arms being pivotable about said first and second anchor points, respectively, in at least a first direction by equal angular amounts to tilt said platform with one degree of freedom in at least the first direction;

said first and second lever arms being pivotable about said first and sccond anchor points, respectively, in it least a first direction by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees of freedom.

35. The system of claim 34 wherein said first and second actuator microstructures are respectively comprised of first and second groups of separate actuators having separate laterally moveable outputs, and said system further comprises:

a first yoke joining said laterally moveable outputs of said first group of actuators together for connection with said first tether; and

a second yoke joining said laterally moveable outputs of said second group of actuators together for connection with said second tether.

36. The system of claim 35 further comprising:

a first displacement multiplier coupling said first tether to said first yoke; and

a second displacement multiplier coupling said second tether to said second yoke.

37. A microelectromechanical system comprising:

a substrata;

a platform;

a first lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a first anchor point on said substrate; and

a second lever arm attached to said platform by at least one compliant member and pivotably attached to said substrate at a second anchor point on said substrate;

said first and second lever arms being pivotable about said first and second anchor points, respectively, in at least a first direction by equal angular amounts to tilt said platform with one degree of freedom in at least the first direction;

said first and second lever arms being pivotable about said first and second anchor points, respectively, in at learnt a first direction by unequal angular amounts to tilt said platform with respect to said substrate with at least two degrees of freedom; and

wherein said first and second lever arms have different lengths measured between where each said lever arm is attached to said substrate and to said platform.