Double-pulse laser-induced forward transfer of thin liquid copper jet: Toward 3D nano-manufacturing

Laser-induced forward transfer appears to be one of the key players of additive manufacturing at the micrometer scale. The basic concept of LIFT consists in the backside laser irradiation of a thin donor film, in solid[1], paste[2] or liquid[3] state, coated on a transparent substrate to transfer a small volume of the donor material onto a receiver substrate placed nearby. From investigations on different states of LIFT, researchers point out the pros and cons of LIFT in solid and liquid phase[4]. In summary, the transfer from a solid donor film often leads to the generation of small debris due to its unstable transfer process. In contrary, liquid films allow a stable transfer process. However, high resolution droplets (<15μm) are hardly printed because dewetting process strongly limits the minimal thickness of the donor liquid film.