How new are nanotechnologies?
Nanotechnology may not be as new as you thought
It may seem that nanotechnology is new and exciting, having emerged around the start of this century. However, some people argue that nanotechnology is just a ‘rebranding’ of older science and that its inﬂuence is evolutionary rather than revolutionary. In the longer term, though, nanotechnologies have the potential to affect manufacturing processes across a wide range of industries; this has already led not just to ‘the same but better’ but to genuinely new products.
Nanoparticles are not new: they have existed widely in the natural world for millions of years, created by living things or by volcanic activity. Nano-effects are astonishingly common in nature – from non-reﬂective moths’ eyes to extraordinarily efﬁcient nanolenses in crystalline sponges. The enamel of our teeth is constructed, in part, through the use of natural nanotechnology. In fact, people have exploited the properties of nanoparticles for centuries. Gold and silver nanoparticles, for example, are responsible for some coloured pigments that have been used in stained glass and ceramics since the tenth century (depending on their size, gold particles can appear red, blue or gold).
Computer chips have been made using nanotechnologies for the past 20 years, and chemists have been making polymers – large molecules made up of nanoscale subunits – for decades.
Today, there are two approaches to manufacturing nanomaterials: ‘bottom-up’ and ‘top-down’. In the ‘bottom-up’ approach, structures are built up atom by atom using sophisticated tools such as the scanning tunneling microscope or atomic force microscope. These can pick up, slide or drag atoms or molecules around to build simple nanostructures. Molecules can also be assembled by chemical synthesis or by self-assembly, whereby atoms and molecules arrange themselves into ordered structures.
In ‘top-down’ approaches, traditional engineering techniques such as machining and etching are used at very small scales. Products therefore tend to be reﬁnements of existing products, such as electronic chips with ever more components crammed onto them.Lead image:
Johan J Ingles-Le Nobel/Flickr CC BY NC ND