US Patent 7544938 - Statistical characterization of nanoparticles

http://www.freepatentsonline.com/7544938.html

In order to effectively use nanoparticles it is important to something about the size distribution of the particles. This patent from FEI teaches forming an electrostatic pattern to attract small groups of nanoparticles sufficient to perform statistical analysis. Claim 1 reads:

1. A method of determining properties of nano-particles, comprising:

forming a charge pattern on a substrate;

distributing nano-particles onto the charge pattern, the charge pattern causing the nano-particles to spread across the surface of the substrate; and

automatically measuring a property of a plurality of nano-particles to determine statistical characteristics of the nano-particle population.