US Patent 7728284 - Polarized optical nanotweezers

http://www.freepatentsonline.com/7728284.html

Two of the primary techniques used to manipulate individual nanoparticles are atomic force microscopy and optical tweezers. This patent from Japan Science and Technology Agency teaches a method of using optical tweezers on groups of quantum dots. Claim 1 reads:

1. A method of manipulating nanosize objects, said method comprising:

illuminating nanosize objects with light resonant with an electronic excitation level of the nanosize objects to induce force being exerted on the nanosize objects from the resonant light for manipulation of the nanosize objects, wherein:

the resonant light illuminates a collection of nanosize objects;

the resonant light is changed in polarization to control mechanical interaction of the nanosize objects; and

the resonant light is changed in polarization so as to excite resonance energy of closely positioned nanosize objects to a level below resonance energy of a single nanosize object.