Tuesday, March 17, 2009

US Patent 7504014 - Electrolytic CNT interconnect method


One problem with bottom-up manufacturing of conductive wires is the establishment of predictable conductivity in the aggregation of the nanoparticles or nanowires forming the wiring. For example, a single nanotube may have an electrical conductivity much higher than that found in a nanotube composite. This patent from Fujitsu teaches one approach to solving this problem by forming metal connections between aligned nanotubes using electrodeposition. Claim 1 reads:

1. A method for manufacturing a carbon nanotube-based nanocircuit, the method comprising:

immersing carbon nanotubes in a solution to provide a suspension of charged nanotubes;

contacting the suspension with a substrate, wherein the substrate is patterned with metallic nanowire segments;

applying an electrical bias to the metallic nanowire segments, thereby causing at least one charged carbon nanotube to align with at least one segment; and

replacing the carbon nanotube suspension with an electrolyte containing ions; and

performing electrodeposition using the electrolyte to provide metal connections between carbon nanotubes.