There is little doubt that molecular motors provide a rich possi-bility for the development of nanoscale devices that are capable of useful work. K.F.’s work in this area started in the early 1970 when he began to study Type I restriction-modification (R-M) systems, or more specifically the EcoR124I Type IC R-M enzyme.2 These complex enzymes were seen as interesting systems for “blue-sky research”, but the fact that they were large, multi-subunit, multifunctional enzymes that cut DNA in a random and highly ATP-dependent manner suggested that they would not be a useful commercial enterprise (unlike the Type II restriction enzymes that led to the revolution in studies of biology that genetic engineering represented). However, as recently detailed,2 the fact that the EcoR124I molecular motor was able to move micron-sized objects over several microns distance provided strong evidence that these motors could act as nanoactuators.22,625 Even so, the idea to commercialise the use of a molecular motor as an active component of a biosensor has taken a number of years and a great deal of investment of time and funds and presents an interesting example of how to move from “blue skies” research to a commercial product. A similar situation has been obvious for a number of other biological molecular motors, where much of the research was carried out by cell biologists who were driven by a need to understand how many

of the more complex tasks that a cell undertakes during its life cycle were accomplished, and which systems provided the driving force. Once the level of understanding for these biological molecular motors reached the level described earlier in this book it became apparent that many of these systems might have commercial potential. Hess et al.626 provided an early description of how biological molecular motor might be used in functional nanoscience and he imagined three main areas: 1. Material transport — where problems associated with

nanofluidics might be overcome by using an active transport system in a manner analogous to the transport systems of the cell. 2. Adaptive materials — where biological molecular motors could be used to rearrange the structure of a material in a

controllable manner. We would also include artificial muscle in such a definition and as indicated below, there is a great deal of potential in this area.