In microfluidic technology,dielectrophoresis(DEP)is commonly used to manipulate particles.In this work,the fluid-particle interactions in a microfluidic system are investigated numerically by a finite difference method(FDM)for electric field distribution and a lattice Boltzmann method(LBM)for the fluid flow.In this system,efficient particle manipulation may be realized by combining DEP and field-modulating vortex.The influence of the density(ρp),radius(r),and initial position of the particle in the y direction(yp0),and the slip velocity(u0)on the particle manipulation are studied systemati-cally.It is found that compared with the particle without action of DEP force,the particle subjected to a DEP force may be captured by the vortex over a wider range of parameters.In the y direction,as ρp or r increases,the particle can be captured more easily by the vortex since it is subjected to a stronger DEP force.When u0 is low,particle is more likely to be captured due to the vortex-particle interaction.Furthermore,the flow field around the particle is analyzed to explore the underly-ing mechanism.The results obtained in the present study may provide theoretical support for engineering applications of field-controlled vortices to manipulate particles.