The Graphene Sheet Patent Landscape
April 7, 2008 – 3:55 pmIn order to complement the previous posting I thought it would be interesting to take a look at some of the patent trends regarding graphene sheet materials. As noted in this recent article of the Nanotechnology Law & Business Journal the terminology associated with carbon nanotubes and related nanostructures can be somewhat inconsistently used in the patent literature leading to difficulties in performing reliable searching of patent databases. For example, while carbon nanotubes are usually described in terms of a rolled up graphene sheets, patents referring to carbon nanotubes rarely make reference to this. In a recent search of issued U.S. patents it was found that “graphene” is referenced in only 349 U.S. patents (as of 4/1/2008) while “carbon nanotube” or “carbon nanotubes” is referenced in 3,354 U.S. patents.
Of course, graphene is a more generic term associated with not just carbon nanotubes but ordinary graphite, which is probably most familiar for it’s use in pencil “leads”. Graphite is essentially multilayer graphene sheets so for inventions based on single sheet graphene it may be proper to consider not just carbon nanotube patents but also patents directed to graphite itself since, as of April 1, 2008, 81,631 U.S. patents make reference to “graphite” which is of course a far greater number of patents than that for carbon nanotubes.
Based on a review of the patents that do recite “graphene” most of these patents are not actually referring to planar (i.e. non-curved) graphene sheets and are instead using terms such as “hollow graphene sheet”, “tubular graphene layers” or “cylindrical graphene sheet” to describe curved carbon nanostructures. The few non-curved graphene patents of interest include:
US Patent 7,015,142 and US Patent 7,327,000 - from Georgia Tech Research teaches basic patterning of single sheet graphene.
US Patent 7,071,258 - from Nanotek Instruments teaching the formation of multilayer graphite plates with thicknesses less than 10 nm.
Currently pending patent applications of interest include:
US Patent Application 2004/0247957 - from Nissan Motor teaching graphene structures for hydrogen storage in fuel cells
US Patent Application 2005/0127334 - from Matsushita Electric teaching graphene structures for electron emission
US Patent Application 2007/0284557 - from Unidym teaching a transparent conductive film formed from graphene
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