Droplet-Confined Electroplating for Nanoscale Additive\nManufacturing: Current Control of the Initial Stages of Growth of\nCopper Nanowires

Droplet-confined\nelectrodeposition enables a precise deposition\nof three-dimensional, nanoscopic, and high purity metal structures.\nIt aspires to fabricate intricate microelectronic devices, metamaterials,\nplasmonic structures, and functionalized surfaces. Yet, a major handicap\nof droplet-confined electrodeposition is the current lack of control\nover the process, which is owed to its dynamic nature and the nanoscopic\nsize of the involved droplets. The deposition current offers itself\nas an obvious and real-time window into the deposition and needs to\nbe analyzed operando. Nucleation and growth dynamics are evaluated\nsystematically. Our results indicate different deposition regimes\nand link the current to both morphology and volume of deposited copper.\nThis allows for optimized electroplating strategies and calibration\nof the slicing algorithms necessary for a controlled deposition of\n3D structures with different solvents. The potential of selecting\nappropriate solvents further readies this novel technique for the\nreliable deposition of functional structures with submicron resolution.