Compound floating pivot micromechanisms

• US 6,220,561 B1
• Filed: 06/30/1999
• Issued: 04/24/2001
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Garcia, Ernest J.
• Primary Examiner(s): Ramirez, Ramon O.
• Assistant Examiner(s): DELUCA, JEROME A
• Application Number:
  US09/346,501
• Time in Patent Office: 664 Days
• Field of Search: 248/487, 248/484, 248/485, 248/486, 248/481, 248/474, 248/478, 248/475.1, 248/476, 248/477, 248/371, 359/290, 359/291, 359/224, 359/225
• US Class Current: 248/487
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• 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

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

Claims

1. A micromechanism comprising a floating pivot, said micromechanism comprising:

a) a first portion;

b) a second portion which is to pivot relative to said first portion;

c) a pivot rod functionally attached to said first portion;

d) a pivot base functionally attached to said second portion; and

,

e) a suspension attached to said first portion and to said second portion such that the second portion is free to pivot relative to the first portion, and such that the pivot rod and the pivot base are suspended in such relative position as to form the floating pivot between the first portion and the second portion.

2. The micromechanism of claim 1, wherein the mutual configuration of the pivot rod, the pivot base, and the suspension limits said pivoting to a single axis.

3. The mechanism of claim 2, wherein said actuator is electrically activated.

4. The mechanism of claim 3, wherein said actuator is an electrostatic actuator.

5. The mechanism of claim 4, wherein said electrostatic actuator comprises an capacitive electrostatic actuator.

6. The mechanism of claim 5, wherein said capacitive electrostatic actuator comprises a compliant capacitive electrode.

7. The mechanism of claim 6, wherein said compliant capacitive electrode comprises a flexible capacitor plate.

8. The mechanism of claim 4, wherein said electrostatic actuator comprises a comb drive.

9. The mechanism of claim 2, wherein the maximum relative tilt about said axis is equal for clockwise and counterclockwise tilting about said axis.

10. The mechanism of claim 2, wherein said at least one actuator consists of a single actuator.

11. The mechanism of claim 10, wherein the single actuator is attached to the mechanism so that it produces a tilt about a restricted tilt axis.

12. The mechanism of claim 2, wherein said at least one actuator consists of a pair of actuators.

13. The mechanism of claim 12, wherein each of said pair of actuators are attached to the mechanism so that they produce a tilt about a common tilt orientation.

14. The mechanism of claim 2, wherein said at least one actuator consists of multiple actuators.

15. The mechanism of claim 14, wherein said multiple actuators comprise at least one group of actuators, each of said group of actuators being attached to the mechanism so that they produce a tilt about a common tilt orientation.

16. The mechanism of claim 2, wherein the mounting platform is functionally attached to a micromirror.

17. The mechanism of claim 2, wherein the mounting platform comprises a micromirror.

18. The mechanism of claim 1, having at least one restricted tilt axis.

19. The mechanism of claim 18, wherein all of said at least one restricted tilt axis are mutually parallel, thereby defining a common tilt orientation.

20. The mechanism of claim 18, wherein said at least one restricted tilt axis consists of only one restricted tilt axis.

21. The mechanism of claim 1, wherein the mounting platform is functionally attached to a micromirror.

22. The mechanism of claim 1, wherein the mounting platform comprises a micromirror.

23. A micromechanical tilt stage, comprising:

a) a stage base;

b) a tilting platform;

c) a set of spring mounting posts attached to the stage base;

d) a set of spring attachment points attached to the tilting platform;

e) at least one floating pivot;

f) a network of suspension springs attached to said spring mounting points and to said spring attachment points; and

,

g) at least one actuator functionally attached to the stage base and to the tilting platform so as to produce relative tilt between the stage base and the tilting platform about at least one axis, each of said at least one axis being defined by the relative positions of said at least one actuator and said at least one floating pivot.

24. The tilt stage of claim 23, wherein said stage base comprises a silicon wafer.

25. The tilt stage of claim 23, wherein said tilting platform comprises a micromirror.

26. The tilt stage of claim 23, wherein said tilting platform consists essentially of a micromirror.

27. The tilt stage of claim 23, wherein said tilting platform comprises a reflective metallic layer.

28. The tilt stage of claim 23, wherein said tilting platform consists essentially of a thin slab of silicon.

29. The tilt stage of claim 23, wherein said network of suspension springs consist essentially of silicon.

30. The tilt stage of claim 23, wherein said at least one floating pivot each comprise a first vertical member attached to the stage base and a second vertical member attached to the tilting platform, the first and second vertical members being disposed so as to form a mechanical pivot when some combination of the at least one actuator is activated.

31. The tilt stage of claim 23, wherein each of the at least one actuators are located near the periphery of the mounting platform.

32. The tilt stage of claim 31, wherein each of the at least one actuators is an electrostatic actuator.

33. The tilt stage of claim 32, wherein at least one of the electrostatic actuators comprises a compliant capacitive electrode.

34. The tilt stage of claim 33, wherein said compliant capacitive electrode comprises a flexible capacitor plate.

35. The tilt stage of claim 23, wherein:

a) said stage base comprises a silicon waver;

b) said tilting platform comprises a micromirror comprising a thin electrically conducting silicon plate;

c) said at least one floating pivot each comprise a first comprising a first vertical member attached to the stage base and a second vertical member attached to the tilting platform, the first and second vertical members each consisting essentially of silicon and being disposed so as to form a mechanical pivot when some combination of the at least one actuator is activated;

d) said network of suspension springs comprises thin silicon sheets; and

,

e) said at least one actuator each comprise a capacitor plate attached to the stage base and means to electrically ground the tilting platform.

36. The tilt stage of claim 35, wherein said micromirror further comprises an optically reflective coating.

37. The tilt stage of claim 36, wherein said optically reflective coating comprises a metallic film.

38. The tilt stage of claim 35, wherein each of said at least one actuator further comprises a compliant capacitive electrode attached to said tilting platform.