Areas
Nanotechnology is less a single discipline than a scale at which physics, chemistry, biology and engineering meet. These are its main working areas.
| Area | What it is | Where it is used |
|---|---|---|
| Nanoparticles | Particles from a few to a hundred nanometres across, of metals, oxides or polymers | Catalysts, pigments, sunscreens, diagnostic tests |
| Carbon nanomaterials | Fullerenes, nanotubes and graphene — carbon as cages, tubes and sheets | Composites, conductive additives, sensors, research |
| Two-dimensional materials | Crystals one or a few atoms thick, beginning with graphene | Research in electronics, membranes and coatings |
| Quantum dots | Semiconductor nanocrystals whose colour is set by their size | Display panels, biological imaging |
| Nanoelectronics | Transistors and memory cells with features from a few to a few tens of nanometres | Current processors and memory chips |
| Nanomedicine | Carriers that protect a drug and deliver it into cells | Liposomal cancer drugs; the lipid nanoparticles of mRNA vaccines |
| Nanophotonics | Structures smaller than the wavelength of light that steer it | Sensors, anti-reflective surfaces, flat lenses |
| DNA nanotechnology | DNA used as a programmable building material rather than as genetic code | Research: nanoscale rulers, scaffolds, containers |
| Molecular machines | Single molecules that rotate, shuttle or switch on command | Research; recognised with the 2016 Nobel Prize in Chemistry |
| Nanometrology | Electron and scanning-probe microscopy, and the standards behind them | Quality control wherever the above are manufactured |
Older than its name
People used nanoparticles long before anyone could see them. The Roman Lycurgus Cup, from the fourth century, looks green in reflected light and red when lit from behind because of gold and silver particles in the glass. Michael Faraday prepared ruby-red colloidal gold in 1857 and correctly guessed that the colour came from particles too small to see.