Biomedical Engineering Reference
In-Depth Information
Molecular Motors and Machines
Serena Silvi and Alberto Credi
1
Introduction
Movement is one of life's central attributes. Nature provides living systems with
complex molecules called motor proteins, which work inside a cell like ordinary
machines built for everyday needs. The development of civilization has always been
strictly related to the design and construction of devices, from wheel to jet engine,
capable of facilitating man movement and traveling. Nowadays, the miniaturization
race leads scientists to investigate the possibility of designing and constructing
motors and machines at the nanometer scale, i.e., at the molecular level. Chemists,
by the nature of their discipline, are able to manipulate atoms and molecules and are
therefore in the ideal position to develop bottom-up strategies for the construction
of nanoscale devices.
Natural molecular motors are extremely complex systems; their structures and
detailed working mechanisms have been elucidated only in a few cases and any
attempt to construct systems of such a complexity by using the bottom-up molecular
approach would be hopeless. What can be done, at present, in the fi eld of artifi cial
molecular motors is to construct simple prototypes consisting of a few molecular
components, capable of moving in a controllable way, and to investigate the chal-
lenging problems posed by interfacing artifi cial molecular devices with the macro-
scopic world, particularly as far as energy supply and information exchange are
concerned. Surely, the study of motion at the molecular level is a fascinating topic
from the viewpoint of basic research and a promising fi eld for novel applications.
In the fi rst section of this chapter, we shall introduce the concepts of molecular
motors and machines, and we describe the bottom-up (i.e., supramolecular) approach
to their construction. We then discuss the characteristics of molecular motors, with
S. Silvi A. Credi (
*
)
Dipartimento di Chimica “G. Ciamician” , Università di Bologna ,
Bologna , Italy
e-mail: alberto.credi@unibo.it
