Mems element having perpendicular portion formed from substrate

• US 6,813,412 B2
• Filed: 07/24/2001
• Issued: 11/02/2004
• Est. Priority Date: 07/24/2001
• Status: Expired due to Fees

• Current Assignee: Michael J. Daneman
• Original Assignee: Michael J. Daneman
• Inventors: Lin, Chuang-Chia
• Primary Examiner(s): Ullah, Akm Enayet
• Assistant Examiner(s): Rahll, Jerry T
• Application Number:
  US09/915,232
• Publication Number:
  US 20030044106A1
• Time in Patent Office: 1,197 Days
• Field of Search: 385/16, 385/18-19, 385/40-42
• US Class Current: 385/19
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 2203/053 Translation according to an axis perpendicular to the substrate
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• CPC Class Codes: B81C 1/00214 Processes for the simultaneaous manufacturing of a network or an array of similar microstructural devices
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• 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 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system

Abstract

A microelectromechanical systems (MEMS) element and a MEMS optical switch are described. The MEMS element comprises a crystalline and moveable element is moveably attached to the substrate. The moveable element includes a perpendicular portion oriented substantially perpendicular to a plane of the substrate. The crystal structure of the perpendicular portion and substrate are substantially similar. The moveable element is capable of motion substantially constrained to a plane oriented substantially perpendicular to a plane of the substrate. In at least one position, a part of a perpendicular portion of the moveable element projects beyond a surface of the substrate. The moveable element may be retained in place by a latch. An array of such structures can be implemented to work as an optical switch. The optical switch may comprise a crystalline substrate and one or more moveable elements moveably attached to the substrate. The various embodiments provide for a robust and reliable MEMS elements that may be simply fabricated and densely packed.

Claims

1. A microelectromechanical systems (MEMS) element, comprising:

a crystalline substrate having a crystal structure characterized by two or more substrate crystal axes;

a moveable element moveably attached to the substrate;

wherein the moveable element includes a perpendicular portion oriented substantially perpendicular to a plane of the substrate;

wherein the perpendicular portion of the moveable element has a crystal structure characterized by one or more moveable element crystal axes;

wherein the crystal structure of the perpendicular portion of the moveable element is substantially the same as the crystal structure of the substrate;

wherein, when the moveable element is in at least one position, a part of the perpendicular portion projects beyond a surface of the substrate;

wherein, when the moveable element is in at least one position, two or more of the moveable element crystal axes are oriented substantially parallel to two or more corresponding substrate crystal axes.

2. The MEMS element of claim 1 wherein the moveable element is substantially restricted to movement in a plane substantially perpendicular to the plane of the substrate.

3. The MEMS element of claim 2 wherein moveable element may rotate about a rotation axis.

4. The MEMS element of claim 3 wherein the rotation axis is substantially parallel to the plane of the substrate.

5. The MEMS element of claim 4 wherein rotation axis is oriented substantially perpendicular to a plane of the moveable element.

6. The MEMS element of claim 1 wherein the perpendicular portion of the moveable element is formed from a portion of the crystalline substrate.

7. The MEMS element of claim 6 wherein the moveable element is formed from the substrate.

8. The MEMS element of claim 1 wherein the moveable element includes a light-deflecting component.

9. The MEMS element of claim 8 wherein the light-deflecting portion includes a reflective coating.

10. The MEMS element of claim 9 wherein the light-deflecting portion is disposed on two sides of the perpendicular portion.

11. The MEMS element of claim 1 wherein the moveable element is moveably attached to the substrate at first surface of the substrate.

12. The MEMS element of claim 11 wherein the substrate includes a second surface;

and

wherein the second surface of the substrate is substantially parallel to the first surface of the substrate.

13. The MEMS element of claim 1:

wherein the movable element includes a clamping plate attached to an edge of the perpendicular portion of the moveable element;

wherein the clamping plate is oriented substantially perpendicular to the moveable element;

wherein the clamping plate is oriented substantially parallel to a first surface of the substrate;

wherein, when the moveable element is in at least one position, the clamping plate engages the first surface of the substrate.

14. The MEMS element of claim 1, further comprising:

an actuator coupled to the moveable element.

15. The MEMS element of claim 14 wherein the actuator includes a magnetic material disposed on the moving element.

16. The MEMS element of claim 14 wherein the actuator includes an electrode.

17. The MEMS element of claim 14 wherein the actuator is thermally or electrostatically actuated.

18. The MEMS element of claim 14 wherein the actuator may move the moveable element between the at least one position in which the perpendicular portion projects beyond the surface of the substrate and a second position.

19. The MEMS element of claim 14 further comprising a biasing element coupled to the moveable element.

20. The MEMS element of claim 1 further comprising a latch coupled to the substrate for retaining the moveable element in at least one position.

21. The MEMS element of claim 20 wherein the latch includes a latch plate and one or more guides for restricting a range of motion of the latch plate.

22. The MEMS element of claim 21 further comprising a stop for restricting a motion of the latch.

23. The MEMS device of claim 21 further comprising an actuator coupled to the latch plate.

24. A MEMS element comprising:

a substrate;

a moveable element moveably attached to the substrate for motion substantially constrained to a plane oriented substantially perpendicular to a plane of the substrate;

wherein the moveable element has a perpendicular portion;

wherein the perpendicular portion is formed from the material of the substrate; and

wherein the perpendicular portion is formed substantially perpendicular to the substrate;

wherein, when the moveable element is in at least one position, a part of the perpendicular portion projects beyond a surface of the substrate.

25. The MEMS element of claim 24 wherein the moveable element is attached to a surface of the substrate that is opposite the surface beyond which the perpendicular portion may project.

26. The MEMS element of claim 24 wherein the perpendicular portion includes a light-deflecting component.

27. The MEMS element of claim 26 wherein the light-deflecting component is a reflective coating.

28. The MEMS element of claim 27 wherein the reflective coating is disposed on two surfaces of the perpendicular portion.

29. The MEMS element of claim 24, further comprising a clamping plate attached to the perpendicular portion.

30. The MEMS element of claim 29, further comprising a flexure attached to the clamping plate and the substrate.

31. The MEMS element of claim 30 wherein the flexure is a torsional flexure.

32. The MEMS element of claim 30 wherein the flexure is a pre-stressed flexure.

33. The MEMS element of claim 32 wherein the pre-stressed flexure is a thermal bimorph flexure.

34. The MEMS element of claim 32 wherein the pre-stressed flexure is an electrostatic zip actuator.

35. An optical switch comprising:

a crystalline substrate having a crystal structure characterized by two or more substrate crystal axes;

one or more moveable elements moveably attached to the substrate;

wherein each moveable element includes a perpendicular portion oriented substantially perpendicular to a plane of the substrate;

wherein the perpendicular portion of each moveable element has a crystal structure characterized by one or more moveable element crystal axes;

wherein the crystal structure of each perpendicular portion is substantially the same as the crystal structure of the substrate;

wherein, when a given moveable element is in at least one position, two or more of the moveable element crystal axes for the given element are oriented substantially parallel to two or more corresponding substrate crystal axes;

wherein, when a given moveable element is in at least one position, a part of the perpendicular portion projects beyond a surface of the substrate.

36. The optical switch of claim 35 wherein one or more of the moveable elements include a light deflecting portion.

37. The optical switch of claim 35, further comprising one or more optical fibers optically aligned with one or more of the optical elements.

38. The optical switch of claim 35 wherein each moveable element is formed from a portion of the crystalline substrate.

39. The optical switch of claim 35 wherein one or more of the moveable elements may rotate about a rotation axis.

40. The optical switch of claim 39 wherein the rotation axis is substantially parallel to the plane of the substrate.

41. The optical switch of claim 40 wherein the rotation axis is substantially perpendicular to a plane of at least one of the moveable elements.

42. The optical switch of claim 35 wherein one or more of the moveable elements may translate in a direction substantially perpendicular to a plane of the substrate.