Wireless sensor networks (WSNs) always consist of many mobile and stationary sensor nodes.Dynamic sensor deployment is one of the key topics addressed in the research of WSNs

which is adopted to improve the coverage and detection probability of WSNs.The performance of virtual force (VF) algorithm may be deteriorated because the stationary sensor nodes will confine the global optimal searching ability.This paper proposes a dynamic sensor deployment strategy for WSNs

so-called virtual force-directed particle swarm optimization (VFPSO).VFPSO combines the VF with particle swarm optimization (PSO)

where the velocity of each particle is updated according to not only the historical local optimal solutions and global optimal solutions but also the virtual forces of sensor nodes.The key motivation of this strategy is to use the virtual force to direct the updating of PSO for improving the convergence speed

and PSO is used to enhance the global searching ability.Simulation results demonstrate that VFPSO has better performance on regional convergence and global searching than VF algorithm and PSO algorithm

and it can implement dynamic sensor deployment efficiently and rapidly.