Micromotion amplifier

• US 5,862,003 A
• Filed: 06/20/1996
• Issued: 01/19/1999
• Est. Priority Date: 06/23/1995
• Status: Expired due to Term

• Current Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Original Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Inventors: Huang, Trent, Saif, Muhammad T. A., MacDonald, Noel C.
• Primary Examiner(s): Spyrou, Cassandra C.
• Assistant Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US08/667,880
• Time in Patent Office: 943 Days
• Field of Search: 359/871, 359/223, 359/224, 359/225, 359/226, 359/291, 359/292, 359/847, 359/846, 359/849, 359/855
• US Class Current: 359/871
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2203/051 Translation according to an axis parallel to the substrate
• CPC Class Codes: B81B 2203/053 Translation according to an axis perpendicular to the substrate
• CPC Class Codes: B81B 2203/058 Rotation out of a plane parallel to the substrate
• CPC Class Codes: B81B 3/0037 For increasing stroke, i.e. achieve large displacement of actuated parts
• 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: H02N 1/008 Laterally driven motors, e.g. of the comb-drive type
• CPC Class Codes: Y10S 359/904 Micromirror
• CPC Class Codes: Y10S 977/70 Nanostructure
• CPC Class Codes: Y10S 977/724 Devices having flexible or movable element
• CPC Class Codes: Y10S 977/725 Nanomotor/nanoactuator

Abstract

A microelectromechanical micromotion amplifier generates a controlled lateral motion in response to a small deformation in the axial direction of a MEM beam or body. Lateral motion is produced by buckling of one or more long slender beams, the buckling motion being relatively large with respect to the axial motion which causes such lateral motion. The beams may be designed with a slight asymmetry to achieve gradual buckling in a desired direction. The device is capable of amplifying a driving motion in the range of 1-5 micrometers to produce a transverse motion in the range of 50-200 micrometers.

Claims

1. A micromotion amplifier, comprising:

an elongated microelectromechanical beam having a first end, a second end, and a longitudinal axis;

a reference;

said first end of said beam being connected to said reference;

an actuator energizable for motion with respect to said reference; and

said actuator being connected to said second end of said beam so that energization of said actuator tends to move said actuator along said longitudinal axis to apply an axial force to said beam and to produce resultant transverse buckling of said beam to thereby convert axial motion of said actuator to amplified transverse motion of said beam in a plane of motion.

2. The amplifier of claim 1, wherein said beam is flexible.

3. The amplifier of claim 2, wherein said beam is asymmetric.

4. The amplifier of claim 1, wherein said beam comprises multiple coaxial rigid segments connected to each other, to said actuator and to said reference by corresponding flexible springs.

5. The amplifier of claim 4, wherein said segments are asymmetric.

6. The amplifier of claim 4, wherein said flexible springs comprise folded beams for controlled motion of said beam in said plane of motion.

7. The amplifier of claim 1, wherein said reference is fixed.

8. The amplifier of claim 1, wherein said reference is movable axially with respect to said beam.

9. The amplifier of claim 1, wherein said reference comprises an intermediate stage mounted for motion with respect to a second reference.

10. The amplifier of claim 1, further including a stage centrally mounted on said beam for controlled transverse motion in response to said axial force.

11. The amplifier of claim 1, wherein said reference comprises an intermediate stage mounted by buckling beams to a second reference for relative motion with respect to said second reference along an X axis, and further including:

a central stage mounted by buckling beams to said intermediate stage for relative motion with respect to said intermediate stage along a Y axis to produce a stage within a stage and controlled motion along X and Y axes.

12. A micromotion amplifier, comprising:

first and second parallel, elongated microelectromechanical beams each having a first end, a second end, and a longitudinal axis;

a reference, said first ends of said beams being connected to said reference;

a stage supported by said beams;

an actuator energizable for motion with respect to said reference, said actuator being connected to said second ends of said beams so that energization of said actuator tends to move said actuator in a direction parallel to the longitudinal axes of said beams to apply an axial force to said beams and to produce resultant transverse buckling of said beam to thereby convert axial motion of said actuator to amplified transverse motion of said beams and controlled transverse motion of said stage in a plane of motion.

13. The amplifier of claim 12, wherein said beams are flexible.

14. The amplifier of claim 13, wherein said beams are asymmetrical.

15. The amplifier of claim 12, wherein each said beam comprises multiple rigid segments connected between said stage and said actuator and multiple rigid segments connected between said stage and said reference.

16. The amplifier of claim 15, wherein said beams are asymmetrically mounted to said actuator and to said reference.

17. The amplifier of claim 16, further including a stop to limit the motion of said actuator to thereby limit the transverse buckling of said beam, and digitizes the tilting of the mirror.

18. The amplifier of claim 17, further including a stop to limit the motion of said actuator to thereby limit the transverse buckling of said beam.