US Patent 7915539 - Carbon nanotube electric part

http://www.freepatentsonline.com/7915539.html

This patent is from Fuji Xerox and includes some relatively broad claims for using carbon nanotubes in forming an electrical component. The priority date for this patent is Feb. 24, 2003. Two nanotube related patents which may interfere with this patent appear to be US 6918284 from the U.S. Navy (priority April 25, 2003) and US 6979244 from Canon. Claim 1 reads:

1. An electric part comprising:

a nonconductive base matrix member;

a carbon nanotube group that is sealed within the nonconductive base matrix member, and wherein the carbon nanotube group includes a plurality of carbon nanotubes, the plurality of carbon nanotubes are electrically connected to each other and are in physical contact with each other, in which substantially only an end portion of a carbon nanotube contained in the plurality of carbon nanotubes is exposed from one surface of the nonconductive base matrix member; and

an electrode that is connected to a side surface of at least one carbon nanotube included in the carbon nanotube group.

US Patent 7674447 - CNT-biopolymer electrical connector

http://www.freepatentsonline.com/7674447.html

This patent is from Fuji Xerox and teaches a new type of bioelectronic interconnect for nanoscale circuitry. Claim 1 reads:

1. An electrical connection structure comprising

plural carbon nanotubes provided as electrodes, and

a biopolymer,

wherein carbon atoms of graphene sheets of the plural carbon nanotubes and the biopolymer are directly fixed with each other at an arbitrary portion of the biopolymer in a stable electrically connected state

wherein the biopolymer is one of DNA and RNA;

the electrodes are in contact with a portion of the biopolymer, and

wherein the electrodes include Na+ ions diffused inside of the carbon nanotubes.

US Patent 7573186 - CNT electrochemical sensor

http://www.freepatentsonline.com/7573186.html

This patent from Fuji Xerox teaches a variation of a carbon nanotube chemical sensor which purportedly produces higher sensitivity. Claim 1 reads:

1. An electrode for electrochemical measurement comprising:

a plurality of carbon nanotubes,

a catalyst causing a specific chemical reaction, and

an insulator in which the carbon nanotubes and the catalyst are embedded,

wherein the carbon nanotubes are electrically connected with each other by chemical bonding to thereby form a network structure, a part of the catalyst is exposed at a surface of the insulator, and a part of the plurality of the carbon nanotubes are exposed at the surface of the insulator to form an electroconductive portion, and the carbon nanotubes are cross-linked with a cross-linking agent having non-self polymerizability.

US Patent 7355334 - Crosslinked CNT electron emitter

http://www.freepatentsonline.com/US7355334.html

This patent from Fuji Xerox claims crosslinking of carbon nanotubes in forming an electron emitter to increase mechanical and electrical stability. Claim 1 reads:

1. An electron beam generator device comprising: a base body having a conductive surface; and an electron-emission electrode having a carbon nanotube structure on the conductive surface of the base body, wherein the carbon nanotube structure constitutes a network structure which has plural carbon nanotubes and a crosslinked part including a chemical bond of plural functional groups, the chemical bond at least connecting one end of one of the carbon nanotubes to another one of the carbon nanotubes.

However, US Patent 6,057,637 was not considered during prosecution and may by relevant as teaching the use of an epoxy matrix and crosslinking carbon based nanotubes for a field emission device (see column 5, line 66 - column 6, line 7).

US Patent 7309404 - Arc discharge CNT manufacture using charcoal electrodes

http://www.freepatentsonline.com/7309404.html

The three main methods of carbon nanotube manufacture are laser ablation, CVD, and arc discharge. The arc discharge method forms carbon nanotubes via the application of a direct current discharge between graphite electrodes in a reduced pressure, inert gas atmosphere. This patent from Fuji Xerox teaches using charcoal in place of the graphite for cheaper cost production. Claim 1 reads:

1. A manufacturing method for a carbon nanotube, comprising: applying a voltage between two electrodes whose tips are opposed to each other; generating discharge plasma in a discharge area between the two electrodes; and using an electrode made of a porous carbonaceous material, wherein said porous carbonaceous material is charcoal as at least one of the two electrodes whose tips are opposed to each other.

US 7244374 - Carbon nanotube/metal composite

http://www.freepatentsonline.com/7244374.html

Metal/carbon nanotube composite material is useful in a variety of applications including improved heat sinks. This patent from Fuji Xerox teaches using cross-linking of functional groups bonded on the carbon nanotube sidewalls to reduce discontinuity of conduction paths and approve the effectiveness of these materials. Claim 1 reads:

1. A composite comprising a carbon nanotube structure and a metal-containing material that are mixed together, wherein the carbon nanotube structure has a network structure constructed by mutually cross-linking functional groups bonded along the lengths of plural carbon nanotubes through chemical bonding of the functional groups together.

US Patent 7228094 - Nanopowder on substrate

http://www.freepatentsonline.com/7228094.html

Yipes! This patent claim from Xerox is directed to a donor used in electrophotography processes but some of the claims appear quite broad.

1. A donor member comprising a substrate and having thereover a coating comprising a nano-size powder having a particle size of from about 25 to about 500 nanometers.

Although the specification of "donor member" may limit the breadth somewhat, many publications to metallic, magnetic, carbon-based, or other nanoparticle films formed on a substrate that would be in the cited range can be found by doing a quick survey of GoogleScholar prior to the priority date of this patent. See for example:
http://www.springerlink.com/content/g554625k1707l80h/

US Patent 7217374 - Carbon nanotube mesh resistor

http://www.freepatentsonline.com/7217374.html

This patent from Fuji Xerox proposes improved resistor material formed using carbon nanotubes including cross-linking the nanotubes via a polymerization reaction. Claim 1 reads:

1. A resistance element comprising an electrical resistance body consisting of a patterned carbon nanotube structure having a mesh structure, in which plural carbon nanotubes are cross-linked to one another through cross-linked sites.

US Patents 7205021 and 7205940 - Carbon nanotube antennas

http://www.freepatentsonline.com/7205021.html - AMBIT CORP. patent
http://www.freepatentsonline.com/7205940.html - FUJI XEROX patent

One of the reasons I created this blog was to recognize the early potential commercialization of nanostructured materials for which patents, as opposed to scientific literature, can be a better judge. There have been several patents, such as the basic nanotube electron emitter patent by Till Keesmann, which have the potential to create entire industries (such as surface emitting displays) and from which hundreds of further patents have been filed.

Another group of fundamental nanotube patents with a lot of potentia,l but for which less of a patent thicket exists, are based on the optical reception and transmission properties of nanotubes. Robert Crowley of Ambit Corp. is arguably the first to patent the uses of carbon nanotubes in antenna elements and US Patent 7,205,021 is a continuation application based on earlier patents with priority going back to 1997. Claim 1 reads:

1. A method of manufacturing and using a device having an array of carbon nanotubes for the receipt and radiation of electromagnetic energy therefrom, comprising: providing a substrate; arranging a predetermined pattern of nanotube growth sites on said substrate; growing at least one electromagnetic energy receiving carbon nanotube from said growth sites on said substrate; receiving electromagnetic energy by said at least one carbon nanotube; and radiating said electromagnetic energy by a carbon nanotube.

Coincidentally another nanotube antenna patent issued this week from Fuji Xerox with priority going back only to 2003. Claim 1 reads:

1. An antenna characterized by comprising: a radiator formed of a carbon nanotube, an electrode that is connected with a part of the carbon nanotube and is for operating the antenna as a monopole antenna.

One of Crowley's earlier patents was cited by the Patent Examiner but the Examiner did not consider Crowley's design to fall under the category of "monopole" antennas since Crowley uses an array of nanotubes. The Examiner used an obviousness type rejection that was successfully refuted by the attorney. However, it seems to me that Crowley's design could be considered a monopole antenna in some sense. Fuji Xerox's patent specification defines a monopole antenna as follows

"That is, the present invention is directed to an antenna characterized by including a radiator made up of a carbon nanotube, and as a specific structure, for example, an antenna characterized by including an electrode that is connected with a part of the carbon nanotube and is for operating the antenna as a monopole antenna. The "monopole antenna" is directed to an antenna that has an electricity feeding portion (an antenna that is provided with an electrode) on an end portion of the radiator, whereas the "bipolar antenna" is directed to an antenna having an electricity feeding portion in the center of the radiator."

Figure 3 of Ambit's patent seemingly illustrates several examples of monopoles by this definition when the nanotube extends from only one side of substrate 11 (although the bipolar type are also included).