A major advance in nanotechnology with far-reaching potential benefits in medicine and other fields is to be announced at this year’s BA Festival of Science in
Scientists have built molecules that can, for the first time ever, move larger-than-atom-sized objects. Constructing molecular machines capable of performing relatively large-scale mechanical tasks has never been achieved before.
Now, chemists at
This step could eventually lead to the development of artificial muscles that use molecular ‘nano’-machines of this kind to help perform physical tasks. Nano-machines could also be used in ‘smart’ materials that change their properties, such as volume, viscosity or conductivity, in response to a stimulus. They could even control the movement of drugs around the body to the exact point where they are needed.
The research has been funded by the Engineering and Physical Sciences Research Council (EPSRC), and has also involved scientists in
David Leigh and his colleagues have achieved their breakthrough by harnessing ‘Brownian motion’, the random movement of molecules caused by collisions with molecules around them. This has involved controlling (or ‘biasing’) Brownian motion so that molecule movements are no longer completely random.
The team has developed a way of covering a gold surface with specially engineered molecules. When stimulated by ultra-violet light, the components of these molecules change position because a chemical reaction takes place in one part of the molecule that causes it to repel another part.
These changes in position dramatically alter the surface tension of a droplet of liquid placed on the gold surface and in this way produce enough energy to move the droplet a distance of up to a millimetre. It may be the tiniest of movements but in the emerging discipline of nanotechnology this represents a giant technological leap forward.
David Leigh says: “Nature uses molecules as motors and machines in all kinds of biological and chemical processes. Although man’s understanding of how to build and control molecular machines is still at an early stage, nanoscale science and engineering could have a life-enhancing impact on human society comparable in extent to that of electricity, the steam engine, the transistor and the Internet.”