ELECTROMECHANICAL SYSTEMS DEVICE WITH PROTRUSIONS TO PROVIDE ADDITIONAL STABLE STATES

• US 20140092110A1
• Filed: 10/01/2012
• Published: 04/03/2014
• Est. Priority Date: 10/01/2012
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Chan, Edward Keat Leem, Reines, Isak Clark, Wen, Bing, Lee, Chong Uk
• Granted Patent: US 9,096,419 B2
• Time in Patent Office: Days
• US Class Current: 345/530
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0163 Spring holders
• 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: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: H01F 2007/1822 using a capacitor to produce a boost voltage
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

This disclosure provides systems, methods, and apparatus for an electromechanical systems (EMS) device with one or more protrusions connected to a surface of the EMS device. In one aspect, the EMS device includes a substrate, a stationary electrode over the substrate, and a movable electrode over the stationary electrode. The movable electrode is configured to move to three or more positions across a gap by electrostatic actuation between the movable electrode and the stationary electrode. When the protrusions contact any surface of the EMS device at one of the positions across the gap, the protrusions change the stiffness of the EMS device. At least one of the surfaces in contact with the one or more protrusions is non-rigid. In some implementations, the protrusions have a height greater than about 20 nm.

Claims

1. An electromechanical systems (EMS) device, comprising:

a substrate;

a stationary electrode over the substrate;

a movable electrode over the stationary electrode and configured to move to three or more positions across a gap by electrostatic actuation between the movable electrode and the stationary electrode; and

a protrusion connected to a surface of the EMS device, wherein the protrusion is configured to change the stiffness of the EMS device when in contact with another surface of the EMS device at one of the positions across the gap, and wherein at least one of the surfaces in contact with the protrusion is non-rigid.

2. The EMS device of claim 1, further comprising a plurality of tethers symmetrically disposed around the edges of the movable electrode, wherein the protrusion is part of a plurality of protrusions and each of the protrusions is connected to each of the tethers.

3. The EMS device of claim 2, further comprising a plurality of posts over the substrate, wherein the movable electrode is connected to the plurality of posts by the plurality of tethers.

4. The EMS device of claim 2, wherein the movable electrode includes a reflective layer having a rigid surface and the plurality of tethers includes a plurality of hinges each having a non-rigid surface.

5. The EMS device of claim 1, wherein the protrusion is connected to a surface of the movable electrode facing the stationary electrode.

6. The EMS device of claim 1, wherein the protrusion is connected to a surface of the substrate facing the movable electrode.

7. The EMS device of claim 1, wherein the protrusion is part of a plurality of protrusions symmetrically disposed about the center of the movable electrode.

8. The EMS device of claim 1, wherein the EMS device is part of an optical device.

9. The EMS device of claim 8, wherein the EMS device is part of an analog interferometric modulator (AIMOD).

10. The EMS device of claim 9, wherein the three or more positions across the gap correspond to different visible wavelengths in each of the positions, wherein one of the positions across the gap is defined at least in part by the height of the protrusion.

11. The EMS device of claim 9, wherein the protrusion defines a plurality of positions across the gap corresponding to a stable color range when the protrusion is in contact with another surface of the EMS device.

12. The EMS device of claim 1, wherein the protrusion has a height greater than about 20 nm.

13. The EMS device of claim 12, wherein the protrusion has a height between about 100 nm and about 200 nm.

14. The EMS device of claim 1, wherein the protrusion is part of a plurality of protrusions, each of the protrusions having a different height.

15. The EMS device of claim 1, further comprising a top electrode over the movable electrode, wherein the movable electrode is configured to move across an upper gap by electrostatic actuation between the movable electrode and the top electrode.

16. The EMS device of claim 1, wherein the EMS device forms a display, the display including:

a processor that is configured to communicate with the display, the processor being configured to process image data; and

a memory device that is configured to communicate with the processor.

17. The EMS device of claim 16, further comprising:

a driver circuit configured to send at least one signal to the display; and

a controller configured to send at least a portion of the image data to the driver circuit.

18. The EMS device of claim 16, further comprising:

an image source module configured to send the image data to the processor, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

19. The EMS device of claim 16, further comprising:

an input device configured to receive input data and to communicate the input data to the processor.

20. An electromechanical systems (EMS) device, comprising:

a substrate;

a stationary electrode over the substrate;

a movable electrode over the stationary electrode and configured to move to three or more positions across a gap by electrostatic actuation between the movable electrode and the stationary electrode; and

means for changing the stiffness of the EMS device connected to a surface of the EMS device, wherein the changing stiffness means is configured to contact another surface of the EMS device at one of the positions across the gap, and wherein at least one of the surfaces in contact with the changing stiffness means is non-rigid.

21. The EMS device of claim 20, further comprising:

means for supporting the movable electrode over the substrate; and

means for tethering the movable electrode to the supporting means and symmetrically disposed around the edges of the movable electrode, wherein the changing stiffness means is connected to the tethering means.

22. The EMS device of claim 20, wherein the changing stiffness means is connected to a surface of the movable electrode facing the stationary electrode.

23. The EMS device of claim 20, wherein the changing stiffness means is connected to a surface of the substrate facing the movable electrode.

24. The EMS device of claim 20, wherein the EMS device is part of an analog interferometric modulator.

25. The EMS device of claim 20, wherein the changing stiffness means has a height greater than about 20 nm.

26. A method of manufacturing an electromechanical systems (EMS) device, comprising:

providing a substrate;

forming a stationary electrode over the substrate;

forming a movable electrode over the stationary electrode, wherein the movable electrode is configured to move to three or more positions across a gap by electrostatic actuation between the movable electrode and the stationary electrode; and

forming a protrusion on a surface of the EMS device, wherein the protrusion is configured to change the stiffness of the EMS device when in contact with another surface of the EMS device at one of the positions across the gap, and wherein at least one of the surfaces in contact with the protrusion is non-rigid.

27. The method of claim 26, further comprising:

forming a plurality of tethers symmetrically disposed around the edges of the movable electrode, wherein the protrusion is part of a plurality of protrusions and each of the protrusions is connected to each of the tethers.

28. The method of claim 26, wherein the protrusion is connected to a surface of the movable electrode facing the stationary electrode.

29. The method of claim 26, wherein the protrusion is connected to a surface of the substrate facing the movable electrode.

30. The method of claim 26, wherein the protrusion has a height greater than about 20 nm.