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Two-electrode setup: from standard electroplating to droplet-confined electroplating. (a) In standard electroplating, the electrolyte is not spatially confined. Meniscus-confined electroplating confines the electrodeposition of metals into a small volume by using a liquid bridge between a solvent-filled capillary and a conductive substrate. This process is still very similar to normal electroplating, as both electrodes are connected through an electrolyte. (b) Droplet-confined electroplating is also based on a solvent-filled capillary in close proximity to a conductive substrate. Applying a high electric potential between an electrode immersed within the capillary and the conductive substrate leads to an electrohydrodynamic ejection of an ion-containing droplet. This droplet then impacts the substrate, the contained ions are reduced, and the droplet evaporates. A repetition of this cycle leads to the formation of an out-of-plane metal nanostructure. Notably, no liquid connection is maintained between the electrolyte reservoir and the individual droplets. , .