Glossary of terms used on NANO Magazine

A

AFM

atomic force microscopy/microscope

Anions

An ion consists of one or more atoms and carries a unit charge of electricity. Those that are negative ions (hydroxyl and acidic atoms or groups) are called anions (cf. cation).

Assembler

A general-purpose device for molecular manufacturing, capable of guiding chemical reactions by positioning molecules.

Atom

The smallest unit of a chemical element, about a third of a nanometre in diameter. Atoms make up molecules and solid objects.

Atomic force microscopy / microscope (AF

Atomic force microscopy is a technique for analysing the surface of a rigid material all the way down to the level of the atom. The atomic force microscope was invented in 1986 uses a mechanical probe to magnify surface features up to 100 000 000 times, and produces 3D images of the surface. AFM uses various forces that occur when two objects are brought within nanometres of each other. An AFM can work either when the probe is in contact with a surface, causing a repulsive force, or when it is a few nanometres away, where the force is attractive. AFM is being used to understand materials problems in many areas, including data storage, telecommunications, biomedicine, chemistry, and aerospace. AFM is derived from a related technology, called scanning tunnelling 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.