Short abstract
An exhibition at the Science Museum, London, until 31 August 2005, after which it will tour the United Kingdom
www.sciencemuseum.org.uk/antenna/nano/index.asp
Rating: ★★★
The Science Museum's latest exhibition defines its subject as the active making, manipulation, and measurement of extremely tiny things. These things are measured in nanometres, with a nanometre being a millionth of a millimetre, or about as far as a fingernail grows in a second.
At the nanoscale, materials behave differently, and it's their weird and wonderful properties that nanotechnology sets out to exploit. Increased reactivity is one such property—a function of the increased ratio of an object's surface area to its volume as it gets smaller. For example, nanoparticles of silver are more reactive than large particles. Attached to cotton fabric, nanoparticles stop bacteria and fungi growing, hence their use in wound dressings and non-smell socks.
Most medical uses of nanotechnology, however, are hypothetical. What research has been done, warns the exhibition, is at an early stage, and interventions will have to undergo rigorous trials before entering clinical practice.
Three possible uses are highlighted: delivering the exact dose of a drug to the intended location, providing new ways to grow and repair body tissues, and using the detection of single molecules in diagnosis. In this diagnostic use, a single strand of DNA, wrapped around a carbon nanotube, recognises other molecules and sends an electronic signal down the carbon nanotube, which transfers the signal to a computer. “Hype or hope?” asks the commentary, and then answers its question: “Tiny sensors under your skin could be sensitive enough to detect one warning molecule in your blood and may eventually be able to send that information direct to your GP's surgery.” Mercifully, we're spared a Fantastic Voyage-like nano-submarine on a mission to dissolve a clot.
Figure 1.
Small is beautiful: nanowire flowers (see www.visions-of-science.co.uk)
Credit: NOVARTIS VISIONS OF SCIENCE 2004/GHIM WEI HO
The inclusion of the words “big deal” in the exhibition's title is presumably aspirational. As a recent Economist survey of nanotechnology pointed out, there's something of an “intellectual-property land-grab” going on, with more investment capital sloshing around than there are good ideas to fund, and a host of countries with significant stakes in nanotechnology research (www.economist.com/surveys/showsurvey.cfm?issue=20050101). The UK Department of Trade and Industry, ever mindful of the financial interests of UK plc, part funded the exhibition and chose its opening day to publish its response to Nanoscience and Nanotechnologies: Opportunities and Uncertainties. Commissioned from the Royal Society and the Royal Academy of Engineering, this report sought to ensure the provision of a regulatory system that would address public concerns and would allow the development of nanotechnologies in a respectable and innovative way.
Nanotechnology is not without its risks, although like its medical benefits, these are mostly theoretical at this stage. To its credit the exhibition doesn't flinch from documenting these, even going to the extent of including an electron micrograph showing carbon nanotubes that have found their way into human skin cells.
Nanoparticles have probably existed since the world began—they're present in volcanic ash, smoke, and even the ocean spray. But this doesn't help us when it comes to manmade nanoparticles, or “natural” nanoparticles in unnaturally high concentrations.