Molecular manufacturing is a branch of nanotechnology that involves the use of nanoscale (extremely small) tools and non-biological processes to build structures, devices, and systems at the molecular level. Nanoscale objects have dimensions on the order of a few nanometers (nm) or less, where 1 nm is equal to a billionth of a meter (10-9 m). Molecular manufacturing is distinct from nanoscale technology, another major branch of nanotechnology in which standard size tools are used to manufacture simple nanoscale structures and devices.
Nanotechnology has potential benefits, including water purification, sanitation, agriculture, alternative energy (particularly photovoltaics), home and business construction, computer manufacturing, communications, and medicine. Nanotechnology also poses risks, including economic disruption, misuse by people or organizations with nefarious intent, evolution of extreme governmental regulation, controversies over morality, and damage to the environment.