| Atomic force microscopy (AFM) is a
technique for analyzing the surface of a rigid material all the way down
to the level of the atom. AFM uses a mechanical probe to magnify surface
features up to 100,000,000 times, and it produces 3-D images of the
surface.
The technique is derived from a related technology, called scanning
tunneling microscopy (STM). The difference is that AFM does not require
the sample to conduct electricity, whereas STM does. AFM also works in
regular room temperatures, while STM requires special temperature and
other conditions.
AFM is being used to understand materials problems in many areas,
including data storage, telecommunications, biomedicine, chemistry, and
aerospace. In data storage, it is helping researchers to "force" a disk
to have a higher capacity. Today's magnetic storage devices typically
have a capacity limit of between 20 and 50 gigabits (billions of bits)
per square inch of storage medium. Researchers are looking into AFM to
help raise read and write densities to between 40 gigabits and 300
gigabits per square inch. No one has yet commercialized AFM technology
for this purpose, but IBM and others are actively pursuing it. |