Nanotechnology

Nanotechnology studies and controls matter whose important dimensions are on the nanoscale, conventionally about $1$–$100$ nanometres. A nanometre is $10^{-9}$ metres. The scientific interest comes from changes in behaviour at these dimensions, including the increasing role of surfaces and, in suitable systems, quantum confinement.^[ref]

For example, subdividing a fixed volume into smaller nanoparticles increases the exposed surface area, changing how much material can participate in a surface reaction. Nanostructures can also alter electrical conductivity, interaction with light and mechanical properties by controlling geometry rather than changing only chemical chemical composition. Useful nanotechnology therefore combines fabrication with measurements of structure and properties, such as electron microscopy or atomic force microscopy.^[ref]

Nanotechnology is the science and engineering of manipulating matter at the nanoscale, typically defined as involving structures ranging from 1 to 100 nanometers (nm) in size. To put this in perspective, a nanometer is one-billionth of a meter, which is about 100,000 times smaller than the diameter of a human hair. Nanotechnology involves the study, design, and application of materials and devices at this incredibly small scale, where unique physical and chemical properties often emerge.