Patent ID: 7879308

Claim:
A method for manufacturing a carbon nanotube device consisting of a carbon nanotube core having an integrally attached graphitic outer layer comprising the steps of: a) preparing a transition metal catalyst on a selected substrate; b) placing said transition metal catalyst and substrate of step (a) in a reaction vessel; c) purging said reaction vessel of step (b) by heating said reaction vessel to a temperature between 500° C. and 750° C. while introducing a gaseous mixture of hydrogen and an inert gas; d) growing said carbon nanotube core by changing said gaseous mixture of step (c) to a stream consisting of approximately 10% carbon-containing gas and approximately 90% inert gas, while increasing said temperature of said reaction vessel to a range between approximately 900° C. and approximately 1000° C.; (e) growing said integrally attached graphitic outer layer on said carbon nanotube core of step (d) by changing said reaction parameters to promote said distinct formation of graphitic carbon material; (f) cutting away a portion of said graphitic outer layer to leave said carbon nanotube core partially exposed to produce the carbon nanotube device resembling a co-axial cable with the carbon nanotube extending a distance from an integrally attached outer graphic layer; (g) etching a 1-5 mil tungsten wire to a sharp tip; (h) fabricating a slot at said sharp tip of said tungsten wire; and (i) welding the graphic outer layer of said carbon nanotube device with said carbon nanotube core to said tungsten tip using focus ion beam technology to deposit metal to the interface between the graphic outer layer and the slot to bond the carbon nanotube device to the tip.