Nanotechnology derives its name from the Greek word for dwarf – nanos. Working with nanostructures – structures with dimensions from 1 to 100 nanometres – means exploring the universe of atoms and molecules, a world invisible to the naked eye.
One nanometre is about the length of ten hydrogen atoms lined up together, or approximately 50,000 times smaller than the diameter of a single human hair. Or to illustrate the point more clearly: the size of a nanoparticle in relation to that of a football is roughly equivalent to that of a football relative to the size of the Earth. Since material properties are highly dependent on particle size, nanoparticles exhibit physical and chemical characteristics that are clearly different from those of solid matter visible to the naked eye. Nanotechnology is therefore not just another step towards miniaturization.
Experts believe that opening up this invisible universe will have a greater impact on our daily lives than the changes precipitated by computer and information technologies over the past two decades. In fact, taking advantage of material properties that rely on nano-structures is nothing new. The Romans and Chinese discovered long-ago how to use metal nanoparticles in glass and ceramics to create colourful effects without knowing the principles of nanotechnology.
Other more recent examples include carbon black – an ultrafine powder used as a filler in the manufacture of rubber tyres since the 1920s – and the titanium dioxide nanoparticles mixed into sun lotions to absorb harmful UV light.
Many popular nano-developments that have come onto the market in recent years were derived directly from nature. The most prominent example is the lotus effect, which prevents dirt accumulating permanently on house walls and car surfaces. Nanoparticles, similar to ultra-fine hairs in special wall paints and waxes, form a closed wafer-thin surface from which – as in a lotus leaf – pollutants simply roll off. wic
