MICROACTUATOR HAVING MULTIPLE DEGREES OF FREEDOM

• US 20090261688A1
• Filed: 04/13/2006
• Published: 10/22/2009
• Est. Priority Date: 04/15/2005
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Todd, Shane T., Xie, Huikai
• Granted Patent: US 8,148,874 B2
• Time in Patent Office: Days
• US Class Current: 310/307
• CPC Class Codes: B81B 3/0035 Constitution or structural means for controlling the movement of the flexible or deformable elements
• 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 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 26/0866 the reflecting means being moved or deformed by thermal means

Abstract

A MEMS vertical displacement device for vertically displacing and tilting a vertically displaceable platform. The vertically displaceable platform may be displaced using a plurality of recurve actuators configured to provide vertical displacement without horizontal movement. The vertically displaceable platform may be tilted about two axes to yield tilting that is advantageous in numerous applications. The recurve actuators may be thermal, piezoelectric or formed from other appropriate materials.

Claims

1. A MEMS vertical displacement device, comprising:

an anchor;

a vertically displaceable platform;

a first side actuator device attached to the anchor at one end and attached to the vertically displaceable platform at another end, wherein the first side actuator is adapted to create vertical displacement; and

a second side actuator device attached to the anchor at one end and attached to the vertically displaceable platform at another end, wherein the second side actuator is adapted to create vertical displacement and the second side actuator is generally parallel to and offset from the first side actuator.

2. The MEMS vertical displacement device of claim 1, wherein the first side actuator device adapted to create vertical displacement comprises at least one first recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the first recurve actuator is attached to the anchor, and a second recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the second recurve actuator is attached to the first end of the first recurve actuator, such that when actuated a second end of the second recurve actuator is vertically displaced above the anchor.

3. The MEMS vertical displacement device of claim 2, wherein the first section of the first recurve actuator is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the first recurve actuator is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

4. The MEMS vertical displacement device of claim 3, wherein the first section of the second recurve actuator is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the second recurve actuator is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

5. The MEMS vertical displacement device of claim 2, wherein the second side actuator device adapted to create vertical displacement comprises at least one first recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the first recurve actuator is attached to the anchor, and a second recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the second recurve actuator is attached to the first end of the first recurve actuator, such that when actuated a second end of the second recurve actuator is vertically displaced above the anchor.

6. The MEMS vertical displacement device of claim 5, wherein the first section of the first recurve actuator of the second side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the first recurve actuator of the second side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

7. The MEMS vertical displacement device of claim 6, wherein the first section of the second recurve actuator of the second side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the second recurve actuator of the second side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

8. The MEMS vertical displacement device of claim 1, further comprising a third side actuator device attached to the anchor at one end and attached to the vertically displaceable platform at another end, wherein the third side actuator is adapted to create vertical displacement and is generally nonparallel with the first side actuator.

9. The MEMS vertical displacement device of claim 8, wherein the third side actuator device adapted to create vertical displacement comprises at least one first recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the first recurve actuator is attached to the anchor, and a second recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the second recurve actuator is attached to the first end of the first recurve actuator, such that when actuated a second end of the second recurve actuator is vertically displaced above the anchor.

10. The MEMS vertical displacement device of claim 9, wherein the first section of the first recurve actuator of the third side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the first recurve actuator of the third side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

11. The MEMS vertical displacement device of claim 10, wherein the first section of the second recurve actuator of the third side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the second recurve actuator of the second side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

12. The MEMS vertical displacement device of claim 8, further comprising a fourth side actuator device attached to the anchor at one end and attached to the vertically displaceable platform at another end, wherein the fourth side actuator is adapted to create vertical displacement and the fourth side actuator is aligned with and offset from the third side actuator.

13. The MEMS vertical displacement device of claim 12, wherein the fourth side actuator device adapted to create vertical displacement comprises at least one first recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the first recurve actuator is attached to the anchor, and a second recurve actuator having a first section that curves in a first direction and a second section that curves is a second direction that is generally opposite to the first direction, wherein a first end of the second recurve actuator is attached to the first end of the first recurve actuator, such that when actuated a second end of the second recurve actuator is vertically displaced above the anchor.

14. The MEMS vertical displacement device of claim 13, wherein the first section of the first recurve actuator of the fourth side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the first recurve actuator of the fourth side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

15. The MEMS vertical displacement device of claim 14, wherein the first section of the second recurve actuator of the fourth side actuator device is formed from a top having a coefficient of thermal expansion that is higher than a coefficient of thermal expansion for an adjacent bottom;

and wherein the second section of the second recurve actuator of the fourth side actuator device is formed from a top having a coefficient of thermal expansion that is lower than a coefficient of thermal expansion for an adjacent bottom.

16. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises a microlens.

17. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises a micromirror.

18. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises a micro-grating.

19. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises a tunable capacitor.

20. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises an infrared detector.

21. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises an optical filter.

22. The MEMS vertical displacement device of claim 1, wherein the vertically displaceable platform comprises a needle.

23. The MEMs vertical displacement device of claim 1, wherein the first and second side actuator devices may be formed from piezoelectric bimorphs.

24. The MEMs vertical displacement device of claim 12, wherein the third and fourth side actuator devices may be formed from piezoelectric bimorphs.

25. A MEMS vertical displacement device, comprising:

an anchor;

a first side actuator device comprising;

at least one first recurve actuator having a first section with a first end attached to the anchor and second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction;

at least one second recurve actuator having a first section with a first end attached to a second end of the at least one first recurve actuator and a second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction;

a vertically displaceable platform attached to the second end of the at least one second recurve actuator; and

a second side actuator device offset from the first side actuator device on an opposite side of the anchor from the first side actuator device, comprising;

at least one first recurve actuator having a first section with a first end attached to the anchor and second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction;

at least one second recurve actuator having a first section with a first end attached to a second end of the at least one first recurve actuator and a second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction.

26. The MEMS vertical displacement device of claim 25, wherein the first side actuator device, the at least one first recurve actuator of the first side actuator device, and the at least one second recurve actuator of the first side actuator device comprises a first actuator formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform and a second actuator aligned with the first actuator and formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform.

27. The MEMS vertical displacement device of claim 26, wherein the second side actuator device, the at least one first recurve actuator of the second side actuator device, and the at least one second recurve actuator of the second side actuator device comprises a first actuator formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform and a second actuator aligned with the first actuator and formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform.

28. The MEMS vertical displacement device of claim 27, further comprising a third side actuator device comprising:

at least one first recurve actuator having a first section with a first end attached to the anchor and second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction; and

at least one second recurve actuator having a first section with a first end attached to a second end of the at least one first recurve actuator and a second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction.

29. The MEMS vertical displacement device of claim 28, wherein the third side actuator device, the at least one first recurve actuator of the third side actuator device, and the at least one second recurve actuator of the third side actuator device comprises a first actuator formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform and a second actuator aligned with the first actuator and formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform.

30. The MEMS vertical displacement device of claim 29, further comprising a fourth side actuator device on an opposite side of the anchor from the third side actuator device, comprising:

at least one first recurve actuator having a first section with a first end attached to the anchor and second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction;

at least one second recurve actuator having a first section with a first end attached to a second end of the at least one first recurve actuator and a second end, wherein the first section curves in a first direction when activated and a second section having a first end attached to the second end of the first section, wherein the second section curves when activated in a second direction that is generally opposite to the first direction.

31. The MEMS vertical displacement device of claim 30, wherein the fourth side actuator device, the at least one first recurve actuator of the fourth side actuator device, and the at least one second recurve actuator of the fourth side actuator device comprises a first actuator formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform and a second actuator aligned with the first actuator and formed from a first recurve actuator coupled to the anchor and a second recurve actuator coupled to a second end of the first recurve actuator and coupled to the vertically displaceable platform.