Laser induced forward and reverse transfer for additive manufacturing of multimaterial micro components

Pulsed laser can be used to eject materials from transparent donors through an ablation based expulsion mechanism. The material ejection can be controlled through the correct design of the donor materials and the laser optical setup. The ejected material in the form of sub-micrometric droplets can be stacked in order to achieve freestanding 3D components in the micrometric scale. This work depicts the use of a femtosecond pulsed UV laser to deposit material from solid donors in forward and reverse transfer modes in a flexible manner. The system architecture and the process development were carried out as a collaboration between Technoprobe and Politecnico di Milano. In the laser induced forward transfer (LIFT) mode, PVD produced pure titanium layers deposited on transparent glass is deposited in a drop-by-drop fashion to produce free- standing 3D micro metal objects. In the laser induced reverse transfer (LIRT) mode solid metals are transferred to transparent media to produce 2D layers with in-situ material mixing capabilities.