"Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications."
(U.S. National Nanotechnology Initiative: www.nano.gov)
In the 21st Century, the term 'nanotechnology' refers to an applied science, focussed upon exploiting novelties arising from size-dependent phenomena exhibited in nanoscale matter.
When dealing with matter below approximately 50 nanometres, the laws of quantum physics supersede those of traditional physics, resulting in changes to a substance's conductivity, elasticity, reactivity, strength, colour, and tolerance to temperature and pressure. Such changes are useful to all industrial sectors where nanotechnology has been suggested as enabling faster, cheaper, smaller, lighter, safer, cleaner and 'smarter' solutions.
Yet, utilising science at the nanoscale is not new. For example, in the 4th Century A.D., the Romans applied gold and silver nanoparticles to colour glass cups. The resulting artefacts were red in transmitted light and green in reflected light - a sophistication not reproduced again until medieval times. There are many scientists today who would argue they have been conducting research in the realms of the nanoscale since well before 1990.
So how come more and more people are talking about nanotechnology as the 'next big thing' if it has 'existed' for such a long time? There are three main reasons. Firstly, only in the past few decades have we really had the experimental means to conduct work focussed on activity at the nanoscale. Emerging tools, including scanning probe microscopy, quantum mechanical computer simulation and soft X-ray lithography, have combined with new synthesis methods, such as chemical vapour deposition, leading to a significantly greater, ever accelerating understanding of scientific endeavour at the nanoscale. These progressions have been paralleled by the discovery of materials such as fullerenes and nanotubes and, in more recent years, stimulated by a flood of government nanotechnology funding in countries such as the U.S., China and Japan.
Secondly, nanotechnology has, as its underlying aim, the desire to manufacture with ultimate precision on the atomic scale in a 'bottom-up' manner. This means that, rather than the traditional approach to manufacturing whereby bulk materials are whittled down, nanotechnology aims to produce devices commencing with the self-assembly of individual atoms into precise configurations, as has been the case with combinational chemistry for many years. Whilst a great deal of nanotechnology continues to utilise 'top-down' processes such as lithography, the gradual trend is towards 'bottom-up' approaches that hold numerous, long-term manufacturing, financial and environmental advantages.
Thirdly, and arguably most importantly, the recognition of nanotechnology as an emerging field demands and creates new levels of multi-disciplinary collaboration and cross-fertilisation amongst the sciences. Practically, this happens because of the integrated exploitation of biological principles, physical laws and chemical properties at the nanoscale. The increasing desire and need to classify technology resulting from nanoscale manipulation and the progressive integration of scientific disciplines at a unifying length-scale, has led to the accepted term 'nanotechnology', under which new research is growing and existing research is often re-classified. Whilst nanotechnology is projected by the U.S. National Science Foundation (NSF) to have a global market value of $1 trillion by 2011, early signs in the information and communications technology (ICT) and textile industries are that nanotechnology is more complementary, than displacing.
