Drop-on-Demand 3 D Metal Printing

We present a novel method for drop-on-demand (DOD) printing of 3D solid metal structures using liquid metal droplets. This method relies on magnetohydrodynamic (MHD)-based droplet generation. Specifically, a pulsed magnetic field, supplied by an external coil, induces a MHDbased force density within a liquid metal filled ejection chamber, which causes a droplet to be ejected through a nozzle. Three-dimensional (3D) solid metal structures of arbitrary shape can be printed via layer-by-layer patterned deposition of droplets with drop-wise coalescence and solidification. We introduce this prototype MHD printing system along with sample printed structures. We also discuss the underlying physics governing drop generation and introduce computational models for predicting device performance.