Tiny Computers Go Where No Computer Has Gone Before

Nanotechnology experts are exploring the capabilities of moleculesthat act like conventional computers but can operate in tiny placeswhere no silicon-based chip or semiconductor can go. Now, for the firsttime, they have used these molecules to perform logic operations andprocess information in spaces a few nanometres across.

This advance has been achieved by chemists at Queen'sUniversity Belfast, with funding from the Engineering and PhysicalSciences Research Council (EPSRC). Professor Amilra de Silva, Chair ofOrganic Chemistry at the university, says: "Computing isn't justconfined to semiconductors. Molecules have been processing informationever since life has been around on our planet. Harnessing thisremarkable ability really does have the potential to make a bigdifference to people's lives."

Molecular information processors placed in nano-spaces cangather, process and supply valuable data on how chemistry and biologyfunction at this tiny scale. Molecules can also be used as informationprocessors in medical and other applications. Portable blood gasanalysers incorporating early breakthroughs in this field are alreadyin use, with total sales of relevant sensor components already reachingUS$35 million.

When the right chemical inputs (e.g. sodium or potassium ions)and ultra-violet, blue, green or red light are applied, the artificialmolecules used by the team respond by emitting light. This 'signal' canbe analysed using a fluorescence spectrometer or even the eye toprovide data about the molecule's environment. Different types of theseinformation processors respond to different chemical inputs anddifferent colours of light.

The underlying principle is based on photosynthesis -- theprocess whereby plants use sunlight to produce food for themselves andfor us -- and is known as photo-induced electron transfer (PET). InPET, light causes electrons to move from one place to another. Thespeed of this process can be controlled by chemical means.

The Queen's University Belfast team is now focusing onimproving the complexity of the logic operations that can be performed.Professor de Silva will be discussing the team's work and illustratingcurrent capabilities at the BA Festival on 7th September.

Notes

Nanotechnology involves manipulating materials on a verysmall scale to build microscopic machines. The prefix 'nano' in'nanotechnology' means one thousand-millionth (10-9). A nanometre, forexample, is one thousand-millionth of a metre.

Professor de Silva's team primarily works with artificial,man-made molecules. This is easier than working with the much moresophisticated natural molecules which perform information processingtasks in living organisms (e.g. running intracellular reactionpathways) that help keep such organisms alive. All the molecules usedare of the type that has a fluorescent section (i.e. they emit lightwhen excited by another, higher-energy form of light).

A semiconductor or 'chip' is a material such as silicon thatconducts electricity, although not as well as copper, aluminium andother metals. They play a key role in computers, mobile phones and manyother products.

This year's BA (British Association for the Advancement ofScience) Festival of Science takes place in Dublin from 3rd -10thSeptember. The event is one of the UK's biggest science festivals andattracts around 400 of the best scientists and science communicatorsfrom home and abroad who reveal the latest developments in research toa general audience. For more information visit www.the-ba.net.

Professor Amilra de Silva will be talking about "LuminescentMolecules as Information Processors" from 10.00 to 12.00 on 7thSeptember at Joly LT, Hamilton Building. Professor de Silva will alsobe taking part in a press conference at 09.00 on 7th September where hewill be discussing his work. Professor David Leigh of EdinburghUniversity, with whom Professor de Silva has worked extensively in thepast, will be talking about "Tooling Up for the Nanoworld: The Magic ofMolecular Machines" on the same day and will also be taking part in thesame press conference.

The Engineering and Physical Sciences Research Council (EPSRC)is the UK's main agency for funding research in engineering and thephysical sciences. The EPSRC invests more than £500million a year in research and postgraduate training, to help thenation handle the next generation of technological change. The areascovered range from information technology to structural engineering,and mathematics to materials science. This research forms the basis forfuture economic development in the UK and improvements for everyone'shealth, lifestyle and culture. EPSRC also actively promotes publicawareness of science and engineering. EPSRC works alongside otherResearch Councils with responsibility for other areas of research. TheResearch Councils work collectively on issues of common concern viaResearch Councils UK. Website address for more information on EPSRC: www.epsrc.ac.uk/