US Patent 7176478 - Nanotube Vacuum Electronics

http://www.freepatentsonline.com/7176478.pdf

Vacuum tubes predate transistors as the switching element of choice and still have several advantages such as higher switching speeds (since electrons have higher mobility in vacuum than silicon). Unfortunately power requirements and size make vacuum electronics impractical on a large scale, that is of course unless someone invents a high efficiency nanoscale electron emitting element. This patent proposes one way to create such vacuum nanoelectronics. Claim 1 reads:

1. A diode, comprised of two electrodes laterally shifted from each other and placed on non conductive substrate, wherein the first electrode includes a dielectric layer deposited on the substrate, a conductive layer placed on top of said dielectric layer and a nanotube placed on top of said first conductive layer, the axis of said nanotube being essentially normal to one of the edges of the said conductive layer while said nanotube protrudes beyond said one of the edges of said conductive layer into the area of a second electrode which includes a conductive layer placed on the substrate next to said one of the edges of said first conductive layer, so that said nanotube is located above and protrudes into the area of said second electrode.

US Patent 7164744 - Nanotube Logic Drivers

http://www.freepatentsonline.com/7164744.pdf

Nantero is the leading U.S. patent holder for nanotube based electronics and, while most of their patents are directed toward non-volatile mechanical memory, more recent patents focus on nanotube based logic or other circuit configurations. This patent is directed toward nanotube switching circuits for driver circuitry .

1. An off-chip driver circuit, comprising: a differential input having a first and second signal links, each coupled to a respective one of two differential, on-chip signals; at least one output link connectable to an off-chip impedance load; and at least one switching element having an input node, an output node, a nanotube channel element, and a control structure disposed in relation to the nanotube channel element to controllably form and unform an electrically conductive channel between said input node and said output node; wherein the input node coupled to a reference signal and the control structure is coupled to the first and second signal links and the output node is coupled to the output link, and wherein the nanotube channel element is sized to carry sufficient current to drive said off-chip impedance load.