Tuesday, September 19, 2006

US Patent 7108841 - E-Field Assisted Nanotube Growth


Growing parallel arrays of vertically oriented nanotubes on a substrate is important for a variety of applications (field emission displays, parallel e-beam lithography, etc.) This patent from Smalley's group at Rice has priority to 1997 and claims using electric fields to assure parallelism when forming single walled nanotubes using catalytic growth. Claim 1 reads:

1. A method for forming a macroscopic molecular array of tubular carbon molecules, said method comprising the steps of: a) providing a nanoscale array of microwells on a substrate; b) depositing a metal catalyst in each of said microwells; and c) directing a stream of hydrocarbon or CO feedstock gas at said substrate under conditions that effect growth of single-wall carbon nanotubes from each microwell, and d) applying an electric field in the vicinity of said substrate to assist in the alignment of said nanotubes growing from said microwells.