Single-step aerosol printing of metallic nanostructures via in-flight plasma reduction

Direct printing of metallic inks rarely achieves functional conductivity in a single step. Most techniques require post-processing, including solvent removal and particle sintering, which restricts applicability in power-limited systems, heat-sensitive substrates, and rapid fabrication scenarios. In this work, we present a plasma-assisted aerosol deposition process that integrates deposition and post-processing into a single step. Using this approach, we demonstrate direct metallization of nickel and copper films at low temperatures. We also demonstrate that co-deposition of precursor inks can produce biphasic
alloyed films. The effects of plasma voltage, wet-gas flow rate, solvent composition, and layer count on film morphology, structure, surface chemistry, thickness, adhesion, and resistivity are systematically investigated. The process yields resistivities of 297 µΩ·cm for nickel and 17 µΩ·cm for copper, comparable to or lower than values reported for other direct-write techniques. The process-structure relationships established in this work provide a framework for enabling rapid metallization in applications such as space manufacturing, printed electronics, and biocompatible coatings on heat-sensitive substrates.