Nanofiber surface based capacitors

• US 7,057,881 B2
• Filed: 03/08/2005
• Issued: 06/06/2006
• Est. Priority Date: 03/18/2004
• Status: Active Grant

• Current Assignee: ONED Material Incorporated
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: Chow, Calvin Y. H., Dubrow, Robert S.
• Primary Examiner(s): Ha, Nguyen T.
• Application Number:
  US11/075,361
• Publication Number:
  US 20050219788A1
• Time in Patent Office: 455 Days
• Field of Search: 361/303, 361/301.5, 361/311, 361/313, 361/502, 361/503
• US Class Current: 361/508
• CPC Class Codes: H01G 11/36 Nanostructures, e.g. nanofibres, nanotubes or fullerenes
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 4/005 Electrodes
• CPC Class Codes: H01G 4/008 Selection of materials
• CPC Class Codes: H01G 4/06 Solid dielectrics
• CPC Class Codes: H01G 4/203 Fibrous material or synthetic material
• CPC Class Codes: H01G 4/33 Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01G 9/04 Electrodes or formation of dielectric layers thereon
• CPC Class Codes: H01L 28/82 with an enlarged surface, e.g. formed by texturisation
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 2201/026 Nanotubes or nanowires
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

This invention provides novel capacitors comprising nanofiber enhanced surface area substrates and structures comprising such capacitors, as well as methods and uses for such capacitors.

Claims

1. An electric capacitor, comprising at least a first electrode surface, which electrode surface comprises a plurality of nanofibers, wherein a density of the plurality of nanofibers ranges from about 0.11 nanofiber per square micron or less to at least about 1000 nanofibers per square micron, from about 1 nanofiber per square micron or less to at least about 500 nanofibers per square micron, from about 10 nanofibers per square micron or less to at least about 250 nanofibers per square micron, or from about 50 nanofibers per square micron or less to at least about 100 nanofibers per square micron.

2. The capacitor of claim 1, wherein the surface comprises a conductive material.

3. The capacitor of claim 2, wherein the conductive material comprises a metal, a semiconducting material, a polymer, or a resin.

4. The capacitor of claim 1, wherein one or more of the surface or the members of the plurality of nanofibers comprises silicon.

5. The capacitor of claim 1, wherein the plurality of nanofibers comprises the same composition as the composition of the first surface.

6. The capacitor of claim 1, wherein the plurality of nanofibers comprises a different composition from the composition of the first surface.

7. The capacitor of claim 1, wherein the plurality of nanofibers is grown on the face of the surface.

8. The capacitor of claim 1, wherein the plurality of nanofibers is deposited on the face of the surface.

9. The capacitor of claim 1, further comprising a dielectric which comprises a nonconductive material and which covers substantially all members of the plurality of nanofibers.

10. The capacitor of claim 9, wherein the dielectric comprises an oxide, a nitride, a polymer, a ceramic, a resin, a porcelain, a mica containing material, a glass, a vacuum, a rare earth oxide, a gas, or other typical dielectrics used in electronic capacitors.

11. The capacitor of claim 10, wherein the dielectric comprises a grown oxide layer.

12. The capacitor of claim 10, wherein the dielectric comprises a naturally occurring oxide layer.

13. The capacitor of claim 10, wherein the dielectric comprises silicon oxide.

14. The capacitor of claim 10, wherein the oxide layer comprises a thickness of from about 1 nm or less to about 1 um, from about 2 nm or less to about 750 nm, from about 5 nm or less to about 500 nm, from about 10 nm or less to about 250 nm, or from about 50 nm or less to about 100 um.

15. The capacitor of claim 10, wherein the oxide layer. comprises a thickness substantially equivalent to the thickness of the electrode surface.

16. The capacitor of claim 1, further comprising a second electrode surface, which second surface comprises a layer of material deposed upon the dielectric covering the plurality of nanofibers.

17. The capacitor of claim 16, wherein the second surface material comprises a conductive material.

18. The capacitor of claim 17, wherein the second surface comprises a metal, a semiconducting material, a polymer, or a resin.

19. The capacitor of claim 18, wherein the second surface comprises an evaporated or sputtered electrically conducting material.

20. The capacitor of claim 19, wherein the electrically conducting material comprises aluminum, tantalum, platinum, nickel, a semiconducting material, polysilicon, titanium, titanium oxide, an electrolyte, or gold.

21. The capacitor of claim 1, wherein a length of the members of the plurality of nanofibers ranges from about 1 micron or less to at least about 500 microns, from about 5 micron or less to at least about 150 microns, from about 10 micron or less to at least about 125 microns, or from about 50 micron or less to at least about 100 microns;

and wherein the diameter of the members of the plurality of nanofibers ranges from about 5 nm or less to at least about 1 micron, from about 10 nm or less to at least about 500 nm, from about 20 nm or less to at least about 250 nm, from about 20 nm or less to at least about 200 nm, from about 40 nm or less to at least about 200 nm, from about 50 nm or less to at least about 150 nm, or from about 75 nm or less to at least about 100 nm.

22. A device comprising the capacitor of claim 1, 9, or 16.

23. The device of claim 22, wherein the device comprises a timepiece, a watch, a radio, a remote control device, a nanodevice, a medical prosthetic, or a medical implant device.

24. An electric capacitor, comprising at least a first electrode surface, which electrode surface comprises a plurality of nanofibers, wherein a density of the members of the plurality of nanofibers increases the surface area of the first electrode surface at least 1.5 times to at least 100,000 times or more, at least 5 times to at least 75,000 times or more, at least 10 times to at least 50,000 times or more, at least 50 times to at least 25,000 times or more, at least 100 times to at least 10,000 times or more, or at least 500 times to at least 1,000 times or more greater in comparison to an area of electrode surface without nanofibers, which area comprises a substantially equal footprint.

25. An electric capacitor, comprising at least a first electrode surface, which electrode surface comprises a plurality of nanofibers, wherein the farad capacity of the capacitor comprises from about at least 1.5 times to at least 100,000 times or more, at least 5 times to at least 75,000 times or more, at least 10 times to at least 50,000 times or more, at least 50 times to at least 25,000 times or more, at least 100 times to at least 10,000 times or more, or at least 500 times to at least 1,000 times or more greater in capacity in relation to a capacitor having an electrode surface of substantially equal footprint but not comprising a plurality of nanofibers.

26. A capacitor comprising a supporting substrate having at least a first electrode surface, a nanostructured thin film layer comprising alumina or aluminum deposited on at least a region of the surface, and a hydrophobic coating deposited on the film layer.

27. The capacitor of claim 26, wherein the hydrophobic coating comprises a diamond-like carbon coating.