Laser-induced forward transfer from healing silver paste films

Laser-induced forward transfer (LIFT) is a nozzle-less printing technique where a controlled amount of material is transferred from a thin film to a receiver substrate with each laser pulse. Conventionally, each laser pulse is directed to a different spot on the donor ink film as the donor substrate is moved together with the receiver surface after each pulse. In this letter, we demonstrate that it is possible to do the LIFT printing of industrial grade silver paste using multiple pulses on the same spot on the donor film due to the healing of the silver paste film. We modify the rheology of the silver paste by adding a lower viscosity solvent and show that the change in material rheology allows for printing in different regimes.