Actuator and method of manufacture

• US 6,307,298 B1
• Filed: 03/20/2000
• Issued: 10/23/2001
• Est. Priority Date: 03/20/2000
• Status: Expired due to Term

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: O'Brien, Gary J.
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US09/531,697
• Time in Patent Office: 582 Days
• Field of Search: 310/309
• US Class Current: 310/309
• CPC Class Codes: B81B 2203/0136 Comb structures
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: H02N 1/008 Laterally driven motors, e.g. of the comb-drive type

Abstract

An actuator includes a support layer (110), a stationary structure (130) located over the support layer and including two portions (131, 132, 731, 732, 831, 832) adjacent to each other and separated from each other by a gap (133), and a movable structure (140, 240, 340, 440, 540, 650, 740, 840) coupled to and located over the support layer, located adjacent to the stationary structure, and movable relative to the stationary structure and the support layer. A portion (143, 243, 343, 443, 543, 643, 743, 843) of the movable structure is located in the gap between the two portions of the stationary structure, and the portion of the movable structure comprises a body (144) and an asymmetric structure (145, 245, 345, 445, 545, 645, 745, 845) extending from the body.

Claims

1. An actuator comprising:

a support layer;

a stationary structure coupled to and located over the support layer and comprising two portions adjacent to each other and separated from each other by a gap; and

a movable structure coupled to and located over the support layer, located adjacent to the stationary structure, and movable in a direction relative to the stationary structure and the support layer,

wherein;

a portion of the movable structure is located in the gap between the two portions of the stationary structure, and

the portion of the movable structure comprises a body having a side substantially parallel to the direction of movement and an asymmetric structure extending from the side of the body and having an edge non-parallel to the direction of movement.

2. The actuator of claim 1 wherein:

an edge of the asymmetric structure extends towards an edge of a first one of the two portions of the stationary structure; and

a portion of the edge of the asymmetric structure is non-parallel to a portion of the edge of the first one of the two portions of the stationary structure.

3. The actuator of claim 1 wherein:

the edge of the asymmetric structure is non-perpendicular to the direction.

4. The actuator of claim 3 wherein:

the edge of the asymmetric structure is substantially straight.

5. The actuator of claim 1 wherein:

the asymmetric structure is movable relative to the body of the portion of the movable structure.

6. The actuator of claim 1 further comprising:

an additional stationary structure located at a first side of the movable structure, coupled to and located over the support layer, and comprising two additional portions adjacent to each other and separated from each other by an additional gap,

wherein;

the stationary structure is located at a second side of the movable structure opposite the first side of the movable structure; and

an additional portion of the movable structure is located in the additional gap between the two additional portions of the additional stationary structure and comprises an additional body and an additional asymmetric structure extending from the additional body.

7. The actuator of claim 6 wherein:

an edge of the additional asymmetric structure extends towards an edge of a first one of the two additional portions of the additional stationary structure;

a portion of the edge of the additional asymmetric structure is non-parallel to the edge of the first one of the two additional portions of the additional stationary structure;

an edge of the asymmetric structure extends towards an edge of a first one of the two portions of the stationary structure; and

a portion of the edge of the asymmetric structure is non-parallel to the edge of the first one of the two portions of the stationary structure.

8. The actuator of claim 6 wherein:

the additional stationary structure and the stationary structure actuate the movable structure along an axis; and

the additional asymmetric structure and the stationary structure each have an edge non-parallel to the axis.

9. The actuator of claim 8 wherein:

the edge of the additional asymmetric structure and the edge of the asymmetric structure are non-perpendicular to the axis.

10. The actuator of claim 8 wherein:

the additional body has a side substantially parallel to the axis; and

the asymmetric structure extends from the side of the additional body.

11. A semiconductor actuator comprising:

a semiconductor layer;

a first stationary structure coupled to and located over the semiconductor layer and comprising two first portions adjacent to each other and separated from each other by a first gap;

a second stationary structure coupled to and located over the semiconductor layer and comprising two second portions adjacent to each other and separated from each other by a second gap; and

a movable structure coupled to and located over the semiconductor layer, having a first side located adjacent to the first stationary structure, having a second side located adjacent to the second stationary structure, and movable relative to the first and second stationary structures and the semiconductor layer,

wherein;

a first portion of the movable structure is located in the first gap between the two first portions of the first stationary structure;

the first portion of the movable structure comprises a first body and a first plurality of asymmetric structures extending from the first body;

a first portion of the first plurality of asymmetric structures is located between the first body and a first one of the two first portions of the first stationary structure;

a second portion of the first plurality of asymmetric structures is located between the first body and a second one of the two first portions of the first stationary structure;

the first stationary structure actuates the movable structure along an axis;

each of the first plurality of asymmetric structures have an edge non-parallel to the axis;

a second portion of the movable structure is located in the second gap between the two second portions of the second stationary structure;

the second portion of the movable structure comprises a second body and a second plurality of asymmetric structures extending from the second body;

a first portion of the second plurality of asymmetric structures is located between the second body and a first one of the two second portions of the second stationary structure;

a second portion of the second plurality of asymmetric structures is located between the second body and a second one of the two second portions of the second stationary structure;

the second stationary structure actuates the movable structure along the axis; and

each of the second plurality of asymmetric structures have an edge non-parallel to the axis.

12. The semiconductor actuator of claim 11 wherein:

the edge of each of the first plurality of asymmetric structures is non-perpendicular to the axis; and

the edge of each of the second plurality of asymmetric structures is non-perpendicular to the axis.

13. The semiconductor actuator of claim 11 wherein:

the first body has two sides substantially parallel to the axis;

each of the first plurality of asymmetric structures extends from one of the two sides of the first body;

the second body has two sides substantially parallel to the axis; and

each of the second plurality of asymmetric structures extends from one of the two sides of the second body.

14. The semiconductor actuator of claim 11 wherein:

each of the first and second pluralities of asymmetric structures have a length of approximately 5-10 micrometers and a width of approximately 3-7 micrometers.

15. The semiconductor actuator of claim 14 wherein:

the edge of each of the first plurality of asymmetric structures forms an angle of approximately forty to fifty degrees with the first body; and

the edge of each of the second plurality of asymmetric structures forms the angle with the first body.

16. A method of manufacturing an actuator comprising:

providing a support layer;

providing a first layer over the support layer; and

forming a movable structure and a stationary structure in the first layer,

wherein;

the movable structure is movable relative to the stationary structure and the support layer;

the stationary structure comprises two portions located adjacent to each other and separated by a gap there between; and

a portion of the movable structure is located between the two portions of the stationary structure and comprises a body and an asymmetric structure extending from the body.