Patent ID: 7633056

Claim:
A process for moving a particle with a device, said device comprising a substrate, a wave guide and a grating, the process comprising: injecting light with wavelength λ into the wave guide, wherein the wave guide is disposed on the substrate; diffracting, with the grating, the light transmitted through the guide to a medium with an index nsuper in which the particle is located, wherein the grating is disposed on the wave guide; and moving said particle above the grating and through said medium by imparting motion to said particle through said medium in a predetermined direction, dependent upon a grating pitch, with a force generated by the diffracting of the light from the grating, said force being expressed as follows: F =nd/c ( C scat +C abs ) I , wherein C scat and C abs are effective diffusion and absorption sections of the particle, I is an intensity diffracted by the grating, nd is the index nsuper of the medium, and c is speed of light.