Combination horizontal and vertical thermal actuator

• US 6,483,419 B1
• Filed: 09/12/2000
• Issued: 11/19/2002
• Est. Priority Date: 09/12/2000
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weaver, Billy L., Hagen, Kathy L., Theiss, Silva K., Goetz, Douglas P., Smith, Robert G., Hamerly, Mike E.
• Primary Examiner(s): VORTMAN, ANATOLY
• Application Number:
  US09/659,282
• Time in Patent Office: 798 Days
• Field of Search: 337/12, 337/14, 337/16, 337/139-141, 337/339, 337/343, 337/393, 337/298, 605/27--29, 310/306-309, 361/163
• US Class Current: 337/393
• CPC Class Codes: B81B 2201/031 Thermal actuators
• CPC Class Codes: B81B 3/0024 Transducers for transforming thermal into mechanical energy or vice versa, e.g. thermal or bimorph actuators electric motors using thermal effects H02N10/00
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 2001/0068 with multi dimensional movement, i.e. the movable actuator performing movements in at least two different directions
• CPC Class Codes: H01H 2061/006 Micromechanical thermal relay
• CPC Class Codes: H01H 2061/008 Micromechanical actuator with a cold and a hot arm, coupled together at one end
• CPC Class Codes: H01H 61/01 Details

Abstract

A micrometer sized, single-stage, horizontal and vertical thermal actuator capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The horizontal and vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above and laterally offset from the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator exhibits horizontal and vertical displacement when current is applied to at least the hot arm.

Claims

1. A horizontal and vertical thermal actuator constructed on a surface of a substrate comprising:

at least one hot arm having a first end anchored to the surface and a free end located above the surface;

a grounding tab electrically coupling the hot arm to the substrate;

a cold arm having a first end anchored to the surface and a free end, the cold arm being located above and laterally offset from the hot arm relative to the surface; and

a member mechanically and electrically coupling the free ends of the hot and cold arms such that the actuator exhibits vertical displacement and horizontal displacement when current is applied to at least the hot arm.

2. The apparatus of claim 1 comprising a flexure formed in the cold arm near the first end thereof adapted to provide controlled bending.

3. The apparatus of claim 2 wherein the flexure comprises at least one of a recess, depression, cut-out, hole, location of narrowed, thinned or weakened material, alternate material or other structural features or material change that decreases resistance to bending in that location.

4. The apparatus of claim 1 wherein the cold arm is electrically isolated from the hot arm.

5. The apparatus of claim 1 comprising a reinforcing member formed in the cold arm.

6. The apparatus of claim 5 wherein the reinforcing member is integrally formed in the cold arm.

7. The apparatus of claim 1 comprising a metal layer extending along the cold arm.

8. The apparatus of claim 1 wherein the at least one hot arm comprises two or more hot arms each having a first end anchored to the surface and free ends located above the surface.

9. The apparatus of claim 1 wherein the at least one hot arm comprises a plurality of hot arms arranged laterally offset and symmetrical with the cold arm.

10. The apparatus of claim 1 comprising a plurality of horizontal and vertical thermal actuators on the substrate.

11. The apparatus of claim 1 comprising at least one optical device mechanically coupled to the horizontal and vertical thermal actuator.

12. The apparatus of claim 11 wherein the optical device comprises one of a reflector, a lens, a polarizer, a wave guide, a shutter, or an occluding structure.

13. The apparatus of claim 11 comprising an optical communication system including at least one optical device.

14. A horizontal and vertical thermal actuator constructed on a surface of a substrate comprising:

a first beam having a first end anchored to the surface and a free end located above the surface;

a second beam having a first end anchored to the surface and a free end located above the surface;

a grounding tab electrically coupling the first and second beams to the substrate;

a member electrically and mechanically coupling the free end of the first beam to the free end of the second beam;

a third beam having a first end anchored to the surface and a free end mechanically coupled to the member, the third beam being located above and laterally offset from the first and second beams relative to the surface; and

first and second electrical contacts electrically coupled to the first ends of the first and second beams, respectively, the actuator exhibiting vertical displacement and horizontal displacement when current is applied to the first and second beams.

15. The apparatus of claim 14 comprising a flexure located on the third beam proximate the first end thereof.

16. The apparatus of claim 15 wherein the flexure comprises at least one recess, depression, cut-out, hole, location of narrowed, thinned or weakened material, alternate material or other structural features or material change that decreases resistance to bending in that location.

17. The apparatus of claim 14 wherein the first and second beams comprise a circuit through which electric current is passed.

18. The apparatus of claim 15 comprising a reinforcing member formed in the third beam.

19. The apparatus of claim 14 comprising a metal layer extending along the third beam.

20. The apparatus of claim 14 wherein at least a portion of any current in the first and second beams passes through the third beam.

21. The apparatus of claim 14 wherein the third beam is generally parallel to the surface in an unactivated configuration.

22. The apparatus of claim 14 comprising a plurality of horizontal and vertical thermal actuators constructed on the substrate.

23. The apparatus of claim 14 comprising at least one optical device mechanically coupled to the horizontal and vertical thermal actuator.

24. The apparatus of claim 23 wherein the optical device comprises one of a reflector, a lens, a polarizer, a wave guide, a shutter, or an occluding structure.

25. The apparatus of claim 23 comprising an optical communication system including at least one optical device.

26. A horizontal and vertical thermal actuator constructed on a surface of a substrate comprising:

at least one hot arm having a first end anchored to the surface and a free end located above the surface;

a cold arm having a first end anchored to the surface and a free end, the cold arm being located above and laterally offset from the hot arm relative to the surface wherein the hot arm and the cold arm comprise a circuit through which electric current is passed; and

a member mechanically and electrically coupling the free ends of the hot and cold arms such that the actuator exhibits vertical displacement and horizontal displacement when current is applied to at least the hot arm.

27. The apparatus of claim 26 comprising a flexure formed in the cold arm near the first end thereof adapted to provide controlled bending.

28. The apparatus of claim 27 wherein the flexure comprises at least one of a recess, depression, cut-out, hole, location of narrowed, thinned or weakened material, alternate material or other structural features or material change that decreases resistance to bending in that location.

29. The apparatus of claim 26 comprising a reinforcing member formed in the cold arm.

30. The apparatus of claim 29 wherein the reinforcing member is integrally formed in the cold arm.

31. The apparatus of claim 26 comprising a metal layer extending along the cold arm.

32. The apparatus of claim 26 wherein the at least one hot arm comprises two or more hot arms each having a first end anchored to the surface and free ends located above the surface.

33. The apparatus of claim 26 wherein the at least one hot arm comprises a plurality of hot arms arranged laterally offset and symmetrical with the cold arm.

34. The apparatus of claim 26 comprising a plurality of horizontal and vertical thermal actuators on the substrate.

35. The apparatus of claim 26 comprising at least one optical device mechanically coupled to the horizontal and vertical thermal actuator.

36. The apparatus of claim 35 wherein the optical device comprises one of a reflector, a lens, a polarizer, a wave guide, a shutter, or an occluding structure.

37. The apparatus of claim 35 comprising an optical communication system including at least one optical device.