# Scanning-tunneling microscope A scanning-tunneling microscope uses voltage deltas on a very small metal tip and very precise motion to detect the structure of surfaces with sub-nanometer precision. It can also move individual atoms [Scanning tunneling microscope - Wikipedia](https://en.wikipedia.org/wiki/Scanning_tunneling_microscope) * Questions * What surfaces does it work on? * Does it always need a vacuum? * How does it actually move atoms? Does it just sort of