Magnetohydrodynamic Drop-on-Demand Liquid Metal 3 D Printing

We present a novel method for liquid metal drop-on-demand (DOD) additive manufacturing of three-dimensional (3D) solid metal structures. This method relies on magnetohydrodynamic (MHD)-based droplet generation. Specifically, a pulsed magnetic field, supplied by an external coil, induces a Lorentz force density within a liquid metal filled ejection chamber, which causes a droplet to be ejected through a nozzle. Three-dimensional 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.