Nanostructured ceramic platform for micromachined devices and device arrays

• US 6,705,152 B2
• Filed: 10/24/2001
• Issued: 03/16/2004
• Est. Priority Date: 10/24/2000
• Status: Expired due to Term

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: NanoProducts Corporation (Nouryon BV)
• Inventors: Routkevitch, Dmitri, Mardilovich, Peter, Govyadinov, Alex, Hooker, Stephanie, Williams, Stephen S.
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US10/004,258
• Publication Number:
  US 20020118027A1
• Time in Patent Office: 874 Days
• Field of Search: 324/694, 438/800, 73/232, 73/310.5, 73/310.7, 295/921
• US Class Current: 73/31.05
• CPC Class Codes: A61L 27/06 Titanium or titanium alloys
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/08 of gallium, indium or thallium
• CPC Class Codes: B01J 23/14 of germanium, tin or lead
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 37/18 with gases containing free hydrogen
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: C01B 3/001 characterised by the uptaking medium; Treatment thereof
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: G01N 27/125 Composition of the body, e.g. the composition of its sensitive layer
• CPC Class Codes: G01N 27/127 comprising nanoparticles
• CPC Class Codes: G01N 33/0004 Gaseous mixtures, e.g. polluted air
• CPC Class Codes: G01N 33/004 CO or CO2
• CPC Class Codes: G01N 33/0047 Organic compounds
• CPC Class Codes: G01N 33/005 H2
• CPC Class Codes: H01F 1/0045 Zero dimensional, e.g. nanoparticles, soft nanoparticles for medical/biological use preparation of fullerenes in general C01B32/15
• CPC Class Codes: H01F 1/405 of IV type, e.g. Ge1-xMnx
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: Y02E 60/32 Hydrogen storage
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y10S 977/89 : Deposition of materials, e.g. coating, cvd, or ald
• CPC Class Codes: Y10T 29/49002 : Electrical device making
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]

Abstract

The present invention discloses a type of nanostructured ceramic platform for gas sensors and sensor arrays. These sensors comprise micromachined anodic aluminum oxide films, which contains extremely high density (e.g., 10¹¹ cm⁻²) nanoscale pores. Sensing materials deposited inside this self-organized network of nanopores have ultra-high surface area and nanometer grain structure, therefore enabling high sensitivity. Refractory nature of alumina ceramic enables the desired robustness, long lifetime and stability in harsh environment. This sensor platform can been used for both chemical gas and physical (humidity, temperature) sensors and sensor arrays.

Claims

1. A device comprising:

a nanostructured anodic alumina substrate having two sides, wherein said anodic alumina substrate comprises substantially parallel nanoscale pores connecting the two sides;

wherein each side of the alumina substrate has at least one deposited layer substantially perpendicular to the nanoscale pores; and

wherein at least one of said deposited layers comprises an electrode.

3. The device of claim 1, wherein said anodic alumina substrate comprises a sensing material inside the nanoscale pores.

4. The device of claim 3, wherein said sensing material is selected from the group consisting of metals, boron, carbon, silicon, salts, polymers, organic compounds, and inorganic compounds.

5. The device of claim 3, wherein said sensing material comprises titanium oxide.

6. The device of claim 3, wherein said sensing material comprises tin oxide.

7. The device of claim 3, wherein said sensing material comprises zinc oxide.

8. The device of claim 1, wherein said device further comprises a microheater.

9. The device of claim 1, wherein said device further comprises an insulating layer.

10. The device of claim 1, wherein the anodic alumina substrate has a thickness of 0.1 μ

m to 500 μ

m.

11. The device of claim 1, wherein said nanoscale pores have a diameter of 1 nm to 500 nm.

12. The device of claim 1, wherein said nanoscale pores are substantially uniform in diameter.

13. The device of claim 1, wherein said layer has a thickness in the range of 0.1 nm to 500 nm.

16. The device of claim 1, wherein said device is a gas sensor.

17. The device of claim 1, wherein said device is a ceramic microdevice.

18. The device of claim 1, wherein said device is an array.

19. The device of claim 1, wherein said device is a photonic sensor.

20. The device of claim 1, wherein said device is an electromagnetic field sensor.

21. The device of claim 1, wherein said device is a biomedical sensor.

22. The device of claim 1, wherein said device is a bolometer.

23. The device of claim 1, wherein said device is a thermal sensor.

24. The device of claim 1, wherein said device is a magnetic sensor.

2. A sensor comprising:

a nanostructured anodic alumina substrate having two sides, wherein said anodic alumina substrate comprises substantially parallel nanoscale pores;

wherein each side of the alumina substrate has at least one deposited layer substantially perpendicular to the nanoscale pores; and

wherein at least one of said deposited layers comprises an electrode.

14. A method of making a device comprising the steps of:

forming an anodic alumina film on an aluminum substrate, wherein said anodic alumina substrate comprises substantially parallel nanoscale pores;

micromachining the anodic alumina him to obtain two surfaces by a technique selected from the group consisting of anisotropic etching and localized anodization; and

depositing at least one layer on each of the surfaces of the anodic alumina film;

wherein at least one layer of the deposited layers is an electrode.

15. The method of claim 14, said method comprising the step of:

depositing another material in the nanoscale pores of the anodic alumina substrate.

25. A device comprising:

a nanostructured anodic alumina substrate, wherein said anodic alumina substrate comprises substantially parallel nanoscale pores and the device functions as a microheater.

29. A product comprising the device of claim 25.

26. A device comprising:

a nanostructured anodic alumina substrate having two sides;

wherein said anodic alumina substrate comprises substantially parallel pores connecting the two sides;

a substance deposited in the nancscale pores of the anodic alumina substrate;

wherein each side of the alumina substrate has at least one deposited layer; and

wherein at least one of said deposited layers comprises an electrode.

30. A product comprising the device of claim 26.

27. A device comprising:

a nanostructured anodic alumina substrate having two sides,

wherein said anodic alumina substrate comprises substantially parallel nanoscale pores connecting the two sides;

wherein each side of the alumina substrate has at least one deposited layer substantially perpendicular to the nanoscale pores; and

wherein at least one of said deposited layers comprises an electrode; and

wherein at least one of the deposited layers and/or the anodic alumina substrate is patterned using a mask.

31. A product comprising the device of claim 27.

28. A product comprising:

a nanostructured anodic alumina substrate having two sides;

wherein said anodic alumina substrate comprises substantially parallel pores connecting the two sides;

a substance deposited in the pores of the anodic alumina substrate;

wherein each side of the alumina substrate has at least one deposited layer substantially perpendicular to the nanoscale pores; and

wherein at least one of the deposited layers and/or anodic alumina substrate is patterned using a mask.