What you're thinking of is likely a Scanning Tunneling Microscope (STM) or a Transmission Electron Microscope (TEM).
* Scanning Tunneling Microscope (STM): This instrument uses a sharp, pointed metal tip to scan the surface of a material. By measuring the quantum tunneling current between the tip and the surface, it can create an image of the individual atoms on the surface.
* Transmission Electron Microscope (TEM): This type of microscope uses a beam of electrons to illuminate the sample. The electrons pass through the sample and are focused by magnetic lenses to produce an image. TEM can achieve much higher resolution than light microscopes, allowing us to see the internal structure of materials, including individual atoms.
While these instruments don't let us "see" atoms in the traditional sense, they allow us to visualize their arrangement and structure, providing incredible insights into the world of the very small.
