Another area is in miniature electromechanical systems (MEMS) in which conventional parts such as gears, cams, and other typical engineering parts are made and used, but these are on a very small scale, usually of a millimeter or less. Measurement of surfaces of these small parts is very difcult because it is not straightforward to adapt existing instruments, or procedures, to the much smaller sizes. The surface characteristics of MEMS come somewhere in between the macro and nano regimes mentioned above, but problems with their measurement do not!