machine has been defined as a discrete number of molecular
components that have been designed to perform mechanical-like
movements (output) in response to specific stimuli (input). It is often
applied more generally to molecules
that simply mimic functions at the macroscopic level. The term is also common
in nanotechnology, and a number of highly
machines have been proposed towards the goal of constructing a molecular assembler.
machines can be divided into two broad categories: synthetic