Torsional hinged MEMS device

• US 20070014512A1
• Filed: 07/05/2006
• Published: 01/18/2007
• Est. Priority Date: 07/05/2005
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Turner, Arthur
• Application Number:
  US11/481,370
• Publication Number:
  US 20070014512A1
• Time in Patent Office: Days
• US Class Current: 385/18
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0154 Torsion bars
• CPC Class Codes: B81B 3/0045 Improve properties related to angular swinging, e.g. control resonance frequency
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 7/1821 for rotating or oscillating mirrors

Abstract

A MEMS scanning system having a MEMS micro-mirror, the device having at least torsional hinge augmented by an applied elastomer element for the damping of excess ringing, and a method of making such a system. The scanning system may be an integral part of, for example, a high-speed optical communication network. In such a system, the MEMS micro-mirror device includes a micro-mirror layer, for example of silicon, from which the hinged micro-mirror is defined. After the torsional hinges are formed, the elastomer is applied and, if necessary, cured. The hinge structure itself may be configured in such a manner as to increase the efficacy of the augmenting elastomer.

Claims

1. A micro-electromechanical system (MEMS) scanning system, comprising:

a mirror element having a reflective surface;

a plurality of torsional mirror hinges connected to the mirror element and defining an axis about which the mirror rotates as the reflective surface changes orientation; and

at least one elastometric element operationally affixed to one of the torsional hinges.

2. The MEMS scanning system of claim 1, wherein the torsional mirror hinges are integrally formed with the mirror element.

3. The MEMS scanning system of claim 1, wherein each of the plurality of torsional mirror hinges operationally affixed to a respective elastomer element.

4. The MEMS scanning system of claim 1, wherein the elastomer element comprises silicone material.

5. The MEMS scanning system of claim 1, further comprising a mirror support structure connected to at least one of the torsional mirror hinges.

6. The MEMS scanning system of claim 5, wherein the mirror support structure is connected to each of the plurality of torsional mirror hinges.

7. The MEMS scanning system of claim 6, wherein the mirror support structure is integrally formed with the plurality of torsional mirror hinges.

8. The MEMS scanning system of claim 7, wherein each of the plurality of torsional mirror hinges is treated with an applied elastomer.

9. The MEMS scanning system of claim 5, wherein the mirror support structure is gimbals.

10. The MEMS scanning system of claim 9, further comprising a plurality of torsional gimbals hinges and defining an axis about which the gimbals rotates as it changes orientation.

11. The MEMS scanning system of claim 10, wherein each of the plurality of torsional gimbals hinges is treated with an applied elastomer.

12. The MEMS scanning system of claim 1, further comprising a light source.

13. The MEMS scanning system of claim 12, wherein the light source is a coherent light source.

14. The MEMS scanning system of claim 13, wherein the MEMS scanning system is an optical communications system.

15. A method for fabricating a MEMS scanning system, comprising:

forming a torsional-hinged micro-mirror in a substrate layer;

mounting the substrate layer onto a base unit; and

applying an elastomer material to at least one torsional hinge.

16. The method of claim 15, wherein the elastomer material is applied to all torsional hinges associated with the micro-mirror.

17. The method of claim 15, further comprising curing the elastomer material.

18. The method of claim 15, further comprising mounting the base unit in a communication network transmit station.

19. The method of claim 18, further comprising operating the micro-mirror to reflect light from a light source in a predetermined scanning pattern in an attempt to locate a communication network receive station.

20. A scanning system, comprising:

a coherent light source;

a micro-mirror operable to rotate about at least one set of torsional hinges to reflect light received from the coherent light source at a plurality of angles; and

an elastomer damping structure applied to at least one of the torsional hinges in the set.