Effect of Pulse Duration on Laser-Induced Forward Transfer of Microdroplets

Laser-induced forward transfer has application prospects in three-dimensional metal microstructure printing. Pulse duration is a critical factor that influences the droplet transfer behavior, but droplet generation and deposition behavior under different pulse durations are unclear at present. In this study, 500 nm copper films were used as the research object to perform a laser-induced forward transfer experiment at five pulse durations. The results show that with an increase in pulse duration, the minimum and maximum energy fluence thresholds of the laser-induced forward transfer process to form complete microdroplets gradually increase, and the pulse duration significantly influences the morphology of deposited microdroplets. Based on the experiment, the processing map of laser-induced forward transfer under different pulse durations was plotted, and the material transfer rates of microdroplet deposition at different pulse durations were calculated. Finally, the large-area microdroplets array was printed using the scan head line-scanning method.