Want to slip into an atomic groove this weekend? No problem, just bring this gleaming chamber along. This is the precision machinery of an atomic force/scanning tunneling microscope, an instrument capable of imaging material surfaces with atomic resolution.
In action, an exceptionally sharp tip comes within a few atomic diameters of the material and raster scans across the surface. To maintain a consistent distance, the tip follows every change in height and texture that it encounters—think of a turntable needle following a record’s grooves, but on the atomic scale. In fact, that tip is essentially a tungsten needle with a radius smaller than just 5 billionths of a meter. And as crazy as that sounds, it’s actually just the last few atoms at the needle’s apex that really drive the resolution. To top all that off, the machine maintains an ultra-high vacuum to keep out any stray molecules that may make the needle jump.
The resulting images show the surface height relative to specific positions, revealing a map of larger features (relatively speaking) such as atomic steps and terraces. But this remarkable microscope can also provide images of individual atoms inside the custom-made materials at our Center for Functional Nanomaterials.