Tuesday, February 17, 2009

US Patent 7491428 - Self assembled monolayer used in CNT alignment


Alignment of nanotubes is important in order to optimize properties such as electrical conductivity and thermal transport. This method from NASA is based on an electric field alignment approach in which a self assembled monolayer is used to facilitate the alignment. Claim 1 reads:

1. A method for the deposition and alignment of carbon nanotubes, comprising the steps of:

providing an assembly that comprises a substrate having at least two electrodes supported thereon and opposing one another with a gap region being defined therebetween;

depositing a carbon nanotube (CNT) attraction material on said substrate in said gap region;

applying an electric potential to said two opposing electrodes wherein an electric field is generated across said gap region;

wetting said CNT attraction material with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein, wherein a first portion of said CNTs are aligned with said electric field and adhered to said CNT attraction material, and wherein a second portion of said CNTs are not adhered to said CNT attraction material; and

removing said carrier liquid and said second portion of said CNTs from said assembly;

wherein said CNT attraction material is a self-assembled monolayer.