How can a scanning tunneling microscope move atoms across a surface?

A scanning tunneling microscope (STM) can move atoms across a surface by utilizing the strong electric field generated between the probe tip and the sample surface.1

By applying a specific voltage—such as four volts in certain experimental setups—the electric field at the tip becomes sufficiently intense to manipulate atoms. This force can be used to remove atoms from the tip and deposit them onto a substrate, or to move existing atoms along the surface. This capability allows researchers to fabricate nanostructures, such as small atomic clusters or islands, effectively patterning surfaces at an unprecedented scale.12