US Patent 7682591 - Selective area nanopartcle positioning

http://www.freepatentsonline.com/7682591.html

This patent from IBM teaches a way to pattern nanoparticles used for the catalytic growth of nanowires or nanotubes. The method is based on deposition into substrate recesses and wiper removal of excess nanoparticles outside of the recesses. Claim 1 reads:

1. A method of positioning nanoparticles on a patterned substrate, the method comprising:

providing a patterned substrate with selectively positioned recesses;

applying a solution or suspension of nanoparticles to the patterned substrate to form a wetted substrate;

dragging a wiper member across a surface of the wetted substrate to remove a portion of the applied nanoparticles from the wetted substrate such that a substantial number of the remaining portion of the applied nanoparticles are disposed in the selectively positioned recesses;

heating the wiped substrate with the remaining portion of the applied nanoparticles disposed in the selectively positioned recesses;

wherein the nanoparticles are catalytic sites for the growth of one-dimensional materials.