METHOD AND APPARATUS FOR FORMING MEMS DEVICE

• US 20110254107A1
• Filed: 10/12/2010
• Published: 10/20/2011
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Packard, Corinne E., Wood, Vanessa C., Bulovic, Vladimir
• Granted Patent: US 8,963,262 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81C 1/00357 involving bonding one or several substrates on a non-temporary support, e.g. another substrate
• CPC Class Codes: B81C 1/0046 using stamping, e.g. imprinting nanoimprinting for making etch masks G03F7/0002
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

The disclosure is generally directed to fabrication steps, and operation principles for microelectromechanical (MEMS) transducers. In one embodiment, the disclosure relates to a texture morphing device. The texture morphing device includes: a plurality of supports arranged on a substrate to support a deformable mirror; an ITO layer; and a Distributed Bragg Reflector (DBR) layer. A pair of adjacent supports form a cavity with the ITO layer and the deformable mirror. When the height of the cavity changes responsive to an external pressure, the internal reflection within the cavity is changed. The change in the height of the cavity causes the exterior texture to morph. Similar principles are disclosed for constructing sensor and actuators.

Claims

1. A MEMS sensor, comprising:

a plurality of cavities projecting from a substrate, the plurality of cavities arranged in an array and each cavity having a hollow space below a surface of the substrate;

a diaphragm layer formed over the array;

a first electrode communicating with the diaphragm which forms the second electrode;

a meter in communication with the first electrode and the second electrode, the meter detecting a capacitance change between the first electrode and the second electrode when the diaphragm is deflected.

2. The MEMS sensor of claim 1, further comprising a controller in communication with the meter, the controller having a processor circuit in communication with a memory circuit, the controller receiving a signal from the meter and identifying a pressure change corresponding to the received signal.

3. The MEMS sensor of claim 1, further comprising a controller in communication with the meter, the controller having a processor circuit in communication with a memory circuit, the controller receiving a signal from the meter and identifying a change in capacitance corresponding to the received signal.

4. The MEMS sensor of claim 1, wherein the second electrode communicates with the bottom electrode to determine a change in capacitance between the top electrode and the bottom electrode as the diaphragm is deflected.

5. The MEMS sensor of claim 1, wherein the diaphragm defines a conductive or a semi-conductive material.

6. The MEMS sensor of claim 1, wherein the plurality of cavities are formed on an elastomeric polymer.

7. The MEMS sensor of claim 1, wherein the substrate is formed from plastic, glass, metal, or other commonly used substrate material and it coated with a conductive layer of metal or Indium Tin Oxide (“

ITO”

).

8. A MEMS sensor, comprising:

a plurality of cavities projecting from a substrate, the plurality of cavities arranged in an array and each cavity having a hollow interior separating a top portion and a bottom portion of the cavity;

a plurality of diaphragm layers formed over the array;

a first electrode communicating with the plurality of diaphragms layers defining a plurality of complementary electrodes;

a meter in communication with the plurality of complementary electrodes for detecting a capacitance change between the at least one first electrode and its respective diaphragm when an external signal impacts the diaphragm.

9. The sensor of claim 8, further comprising a controller in communication with the meter, the controller having a processor circuit in communication with a memory circuit, the controller receiving a signal from the meter and identifying a pressure change corresponding to the received signal.

10. The sensor of claim 8, further comprising a controller in communication with the meter, the controller having a processor circuit in communication with a memory circuit, the controller receiving a signal from the meter and identifying a change in capacitance corresponding to the received signal.

11. The sensor of claim 8, wherein at least one of the complementary electrode pairs determines a change in potential between the first electrode and the diaphragm when the diaphragm is deflected.

12. The sensor of claim 8, wherein the diaphragm defines a conductive or a semi-conductive material.

13. The sensor of claim 8, wherein the plurality of cavities are formed on an elastomeric polymer.

14. A tunable mirror, comprising:

a plurality of supports arranged on a substrate to support a deformable reflector;

an ITO layer; and

a Distributed Bragg Reflector (DBR) layer;

wherein two adjacent supports form a cavity with the ITO layer and the deformable reflector, and wherein the height of the cavity is adjusted to change an internal reflection within the cavity.

15. The tunable mirror of claim 14, wherein the deformable reflector further comprises a multilayer structure having a gold film, a silver film and DCM-doped organic dye layer.

16. The tunable mirror of claim 15, wherein the organic dye is selected to emit in at least one of UV, visible, or IR wavelengths.

17. The tunable mirror of claim 15, wherein the deformable reflector is reflective at the dye emission wavelengths.

18. The tunable mirror of claim 14, further comprising a first electrode and a second electrode, the first electrode communicating with the DBR layer and the second electrode communicating with the deformable reflector.

19. The tunable mirror of claim 14, further comprising a laser source for optically pumping the organic dye in the DBR layer.

20. A method for mapping a spatially resolved pressure, the method comprising:

forming an array of cavities on a substrate;

forming a sensitive diaphragm over the array of cavities;

mapping a plurality of regions of the array and correlating said regions a plurality of identified cavities;

measuring the movement of each diaphragm against a baseline; and

correlating the measured movement as a function of the diaphragm deflection caused by an external energy source.

21. The method of claim 20, further comprising mapping the location of movement to provide a spatially resolved map of the pressure change.

22. The method of claim 21, wherein the diaphragm is sensitive to a frequency band in one an audible range.

23. The method of claim 21 wherein the diaphragm is sensitive to a frequency band in one an ultrasound range.

24. The method of claim 20, wherein the baseline defines the height of each post not subjected to an external force.

25. The method of claim 20, wherein the diaphragm is a sensor fabric.

26. The method of claim 20, wherein at least one diaphragm deflects in response to external pressure.

27. A method for changing texture of a device, the method comprising:

forming an array of cavities on a substrate;

forming a diaphragm over the array of cavities;

mapping a plurality of regions of the array and correlating said regions a plurality of identified cavities;

forming a closed circuit between at least one of the cavities in the array and the diaphragm; and

supplying a bias to the closed circuit, the bias appraised to cause a deflection in the diaphragm thereby changing the texture of the device.

28. The method of claim 27, further comprising biasing a first region of the array to thereby target a deflection in the first region.

29. The method of claim 27, further comprising biasing a first and a second region of the array to thereby target a deflection in two regions of the diaphragm.