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, in an unprecedented breakthrough, chemists at Edinburgh University have used light to stimulate man-made molecules to propel small droplets of liquid across flat surfaces and even up 12° slopes against the force of gravity. This is equivalent to tiny movements in a conventional machine raising objects to over twice the height of the world's tallest building.
This significant 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 (e.g. volume, viscosity, 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 Italy and the Netherlands. David Leigh, Forbes Professor of Organic Chemistry and EPSRC Senior Research Fellow, leads the Edinburgh University team.
David Leigh and his colleagues have achieved their breakthrough by harnessing a natural biological mechanism called '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 (this is 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."
David Leigh will be discussing his work and showing videos of droplet movement during his talk at the Festival on 7th September. A detailed report has also been published in the latest edition of Nature Materials ('Nanoshuttles move droplets uphill'; Vol. 4, pp.704-710, 2005).
Notes for Editors
Nanotechnology involves manipulating materials on a very small scale to build microscopic machines. The prefix 'nano' in 'nanotechnology' means one thousand-millionth (10-9). A nanometre, for example, is one thousand-millionth of a metre.
This year's BA (British Association for the Advancement of Science) Festival of Science takes place in Dublin from 3rd -10th September. The event is one of the UK's biggest science festivals and attracts around 400 of the best scientists and science communicators from home and abroad who reveal the latest developments in research to a general audience. For more information visit www.the-ba.net.
Professor David Leigh will be talking about "Tooling Up for the Nanoworld: The Magic of Molecular Machines" from 14.00 to 16.00 on 7th September at Joly LT, Hamilton Building. Professor Leigh will also be taking part in a press conference at 09.00 on 7th September where he will be discussing his work. Professor Amilra de Silva of Queen's University Belfast, with whom Professor Leigh has worked extensively in the past, will be talking about "Luminescent Molecules as Information Processors" on the same day and will also be taking part in the same press conference.
The Engineering and Physical Sciences Research Council (EPSRC) is the UK's main agency for funding research in engineering and the physical sciences. The EPSRC invests more than £500 million a year in research and postgraduate training, to help the nation handle the next generation of technological change. The areas covered range from information technology to structural engineering, and mathematics to materials science. This research forms the basis for future economic development in the UK and improvements for everyone's health, lifestyle and culture. EPSRC also actively promotes public awareness of science and engineering. EPSRC works alongside other Research Councils with responsibility for other areas of research. The Research Councils work collectively on issues of common concern via Research Councils UK. Website address for more information on EPSRC: www.epsrc.ac.uk/
For more information, contact:
Professor David Leigh, University of Edinburgh, tel: 0131 650 4721, e-mail: david.leigh@ed.ac.uk (during the festival Professor Leigh can be contacted via Jane Reck – see mobile number below).
Two images: (in .wmv format ie windows media video) are available from the EPSRC Press Office, contact Lisa Green, tel: 44-179-344-2806, e-mail: lisa.green@epsrc.ac.uk (droplet on flat.wmv and dropletuphill12degrees.wmv), suggested caption for both: "Science on the move – for the first time man-made molecules are propelling larger-than-atom-sized objects."
Jane Reck, EPSRC Press Officer, tel: 01793 444312, mob: 07990 848751, e-mail: jane.reck@epsrc.ac.uk Craig Brierley, Press Officer, British Association for the Advancement of Science, tel: 020 7019 4947, e-mail: Craig.Brierley@the-ba.net