Making molecular machines work

Abstract

In this review we chart recent advances in what is at once an old and very new field of endeavour--the achievement of control of motion at the molecular level including solid-state and surface-mounted rotors, and its natural progression to the development of synthetic molecular machines. Besides a discussion of design principles used to control linear and rotary motion in such molecular systems, this review will address the advances towards the construction of synthetic machines that can perform useful functions. Approaches taken by several research groups to construct wholly synthetic molecular machines and devices are compared. This will be illustrated with molecular rotors, elevators, valves, transporters, muscles and other motor functions used to develop smart materials. The demonstration of molecular machinery is highlighted through recent examples of systems capable of effecting macroscopic movement through concerted molecular motion. Several approaches to illustrate how molecular motor systems have been used to accomplish work are discussed. We will conclude with prospects for future developments in this exciting field of nanotechnology.

High‐Power Actuation from Molecular Photoswitches in Enantiomerically Paired Soft Springs

“…Designing shape‐morphing materials has become a major scientific challenge, with implications ranging from soft robotics1, 2, 3 to realizing the full potential of artificial molecular machines 4, 5, 6, 7, 8. The variety of movements seen in the plant and animal kingdoms have provided inspiration for the engineering of soft robots of all kinds,9, 10, 11, 12, 13, 14 and in particular, the realization that plant mechanics often rely on dynamic helical systems15, 16, 17, 18, 19 has motivated the development of a variety of chiral actuators where molecules were used either as active transducers of energy11, 13, 20, 21 or as relays for humidity or temperature changes 22, 23, 24, 25.…”

Constructing an Array of Anchored Single-Molecule Rotors on Gold Surfaces

“…DOI: 10.1103/PhysRevLett.101.197209 PACS numbers: 85.85.+j, 63.20.dk, 68.37.Ef, 82.37.Gk The motion of single atoms or molecules plays an important role in nanoscale engineering at the single atomic or molecular scale [1,2]. The controllability of molecular motion is critical for molecular motors [3], which may convert external energy into orchestrated motion at the molecular level [4,5]. For molecular rotors [6] a high level of control over the rotation axis and, equivalently, selfassembly on a very large scale, are the key ingredients for their integration into complex molecular machines.…”

Help from above

“…These walkers have also recently been used in nanoscale assembly lines, picking up different types of cargo as they move along a track 4 . Moreover, nanoscale analogues of various macroscopic devices have been created 5 , including rotors, motors, switches, turnstiles and elevators, as well as some slightly more esoteric miniatures such as wheelbarrows and guitars.…”