What is nanotechnology?*
Nanotechnology is defined as the purposeful engineering of matter on the atomic or molecular scale. Nanotechnology and nanoscience (the study of nanoscale phenomena) happen between the range of 100 nm down to the atomic level (approximately 0.2 nm), and it is only in recent years that sophisticated tools have been developed to investigate and manipulate matter in this range. New insights have greatly affected our understanding of the nanoscale world, including the change in behavior compared with the same materials at a larger size.
Two main reasons for the difference in properties is that nanomaterials have an increase in relative surface area and a dominance of quantum effects. These factors can change or enhance properties such as strength and electrical characteristics. As a material shrinks to nano-size, there is an increase in the surface area to volume ratio (a greater portion of the atoms are found at the surface area compared to those inside). As catalytic chemical reactions occur at the surface, nanoparticles will be much more reactive than the same mass of the material made up of larger particles. So, for nanomaterials, surface reactions become dominant. In tandem with the surface-area effects, quantum effects begin to dominate. This can significantly change a material’s optical, magnetic or electrical properties.
These size-dependent properties have been known for centuries; gold and silver nanoparticles have been used as colored pigments in stained glass and ceramics. Depending on the size, gold particles can appear in red, blue or gold color. It was later discovered, as explained by Nano.gov, that the motion of gold’s ecectrons is confined. Because this movement is restricted, gold nanoparticles react differently with light compared to larger-scale gold particles. Their size and optical properties can be put to practical use in medical imaging.
Nanomaterials in commercial products
Nanotechnology encompasses a wide range of technological developments in areas as diverse as healthcare, manufacturing and agriculture. Nanomaterials can nowadays be found in many commercial products. Think about certain sunscreens, paints, rubber tires, medical implants, computer chips and many more. Nanoparticles in products are not fixed (such as sunscreens), be used to form composites from which they might later be released (nanoparticles in paint), or be created if nanomaterials are damaged or break down (rubber tires). In sunscreens, nanosized titanium dioxide and zinc oxide are used to absorb and reflect ultraviolet rays while still occurring transparent to the visible light. This is a nice technology to protect consumers from sunburn, but as the nanoparticles are not fixed they could penetrate the skin. although suncreen reduces the risk of sunburn, skin penetration of nanoparticles may also not be without consequences. Also, some other nanoparticles or fibres (asbestos and quartz) have shown to cause harm to humans or the environment when released into the air. For this reason, the safety of ingredients in new emerging technologies is increasingly included in safety assessments. For more information about nanotechnologies please see the three booklets on food, energy and health.
*Information was derived from Royal Society and Royal Academy of Engineering (2004) Nanoscience and nanotechnologies: opportunities and uncertainties
Public engagement in nanotechnology
As nanotechnology aims to exploit the effects of nanomaterials to create new structures and devices with innovative properties and functions, novel applications of nanotechnologies have been introduced. Whereas beneficial innovations have been welcomed, we just explained it may not be without consequences. Some novel nanotechnologies have raised social and ethical concerns with society and contributed to a wider societal debate. Interested in joining the debate? Search in our snapshot public engagement database to find out how you can participate.