Systems and methods for overcoming stiction

• US 6,791,235 B2
• Filed: 11/20/2003
• Issued: 09/14/2004
• Est. Priority Date: 02/28/2002
• Status: Expired due to Fees

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: PTS Corporation
• Inventors: Miller, David, Anderson, Robert L., Muller, Lilac
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US10/719,857
• Publication Number:
  US 20040101234A1
• Time in Patent Office: 299 Days
• Field of Search: 310/309, 310/311, 310/328, 359/225, 359/291, 359/295, 385/18, 335/79
• US Class Current: 310/311
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81C 1/00968 Methods for breaking the stiction bond
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/352 the reflective optical element having a shaped reflective surface, e.g. a reflective element comprising several reflective surfaces or facets that function together
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3564 Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
• CPC Class Codes: G02B 6/3568 characterised by the actuating force
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: H02N 1/002 Electrostatic motors
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence

Abstract

A number of methods and systems for overcoming stiction are provided. The systems include electro-mechanical systems capable of exerting a variety of forces upon areas prone to stiction. The systems can be MEMS arrays or other types of devices where stiction related forces occur. The methods include a variety of ways of causing movement in areas prone to stiction forces. Such movement can be vibrational in nature and is sufficient to overcome stiction, allowing a trapped element to be moveed to a desired location.

Claims

1. An electro-mechanical system, the system comprising:

a mechanical stop;

a structural plate disposed relative to the mechanical stop, wherein a side of the structural plate contacts the mechanical stop; and

an actuator, wherein application of a DC voltage to the actuator causes the mechanical stop to move relative to the structural plate from a static position to a displaced position, and wherein removal of the DC voltage causes a movement of the mechanical stop from the displaced position to the static position, and wherein the movement is sufficient to overcome stiction forces between the structural plate and the mechanical stop.

2. The system of claim 1, wherein the movement comprises an oscillation of the mechanical stop.

3. The system of claim 2, wherein the oscillation comprises displacement of the mechanical stop from the displaced position passed the static position to an overshoot position and back to the static position.

4. The system of claim 1, the system further comprising a base layer, wherein the structural plate is supported above the base layer by a pivot and the mechanical stop is disposed over the base layer.

5. The system of claim 4, wherein the actuator is a first actuator, the system further comprising a second actuator, wherein application of a force to the second actuator causes the structural plate to deflect into contact with the mechanical stop.

6. The system of claim 1, wherein the system comprises an optical routing apparatus comprising a moveable micro-mirror.

7. The system of claim 1, wherein the mechanical stop is comprised of a material and the movement of the mechanical stop comprises an oscillation having a frequency at or near a resonant frequency, or a harmonic thereof, of the material.