Researchers at the University of Oldenberg are currently exploring the limits of how small they can 3D print metals.

The team is currently able to print as small as a single molecule, with the ultimate goal of printing atom by atom. This will open up many potential applications in the areas of microelectronics, nanorobotics, sensor and battery technologies.

https://phys.org/news/2022-12-atom-lab-explores-nanoscale-3d.html