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This paper reports a microfluidic microparticles sorting generator by using the optical force and hydrodynamic forces.Micro/Nanoparticles ranging in size from 70 nm to 1 μm can be aligned and focused in the core flow stream by hydrodynamic focusing [1-3].The particles can be subsequently manipulated by the optical force and liquid stoke forces.The particles with different size and refractive indices can be selected by the optical forces and drag force,flowing with different traces.It has a great potential in cell,or molecule sorting and separating.Figure 1 shows the schematic of the nano-optofluidic system,which consists of three flow streams in a microchannel.Nanoparticles are flowing in the core flow stream by the hydrodynamic effect.A single-mode optical fiber is injected vertically.When the particles flow in the microchannel,they will be controlled by three forces: the optical gradient force that pushes particles to the higher intensity,the radiation force that exists in the direction of light propagation,and the drag force that hinders the velocity change of the particles.In principle,larger particles are more easily to be moved by optical forces while smaller particles are easily blocked by the drag force due to its smaller specific surface area.As a result,particles with different sizes can be sorted by a suitable flow rate and input power in the microchannel.Figure 2 shows that optical forces are very sensitive to the refractive indices and extinction coefficient of particles.Fig.3 shows the simulation results of the nanoparticles under optical field in the central of the input power.Fig.4 shows the images of the sorting traces of different size particles in the microchannel under the optofluidic forces with different diameters.In conclusion,an optofluidic device for single cell and molecule sorting by using optical force combined with the hydrodynamic focusing is demonstrated.