The Jet formation in Ring-shape Laser Induced forward transfer

In this study, ring-shape laser spot was used to induce a ring-shape cavitation aiming to improve the separation accuracy in the laser induced forward transfer (LIFT) process. The roles of laser pulse energy and the size of the ring-shape laser spot on jet formation in LIFT process were theoretically analyzed with ring-shape bubble collapse model established by Lattice Boltzmann Method. The results show that the geometrical symmetry of the ring-shape cavitation blocks the interaction between the inner and outer liquids, leading to higher separation accuracy. The simulation results show that under a specific ratio of internal and external diameter of the ring-shape laser spot, a secondary produced vortex velocity flow can further promote the accuracy of the transferring.