Toward intelligent molecular machines: Directed motions of biological and artificial molecules and assemblies

An overview of studies on biological molecular machines is given, focusing on their "programmed" motions and potential applications to the fabrication of movable nanodevices. Examples of semibiological and fully synthetic molecules and related assemblies that are capable of performing directed motions in response to certain stimuli are considered. The review aims to bring together the research areas of biological and artificial molecular machineries, which have most often been discussed separately, and to initiate a new paradigm for the development of intelligent nanodevices.