Nanotechnology comprises technological developments on the nanometer scale, usually 0.1 to 100 nm. (One nanometer equals one thousandth of a micrometer or one millionth of a millimeter.) The term has sometimes been applied to microscopic technology. This article discusses nanotechnology, nanoscience, and "molecular nanotechnology."
The term nanotechnology is sometimes conflated with molecular nanotechnology (also known as "MNT"), a theoretical advanced form of nanotechnology believed by some to be achievable at some point in the future, based on productive nanosystems. Molecular nanotechnology would fabricate precise structures using mechanosynthesis to perform molecular manufacturing. Molecular nanotechnology, though not yet existent, is posited by its proponents to have a great impact on society if realized.
More broadly, nanotechnology includes the many techniques used to create structures at a size scale below 100 nm, including those used for fabrication of nanotubes and nanowires, those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers.
The term nanoscience is used to describe the interdisciplinary fields of science devoted to the study of nanoscale phenomena employed in nanotechnology. This is the world of atoms, molecules, macromolecules, quantum dots, and macromolecular assemblies, and is dominated by surface effects such as Van der Waals force attraction, hydrogen bonding, electronic charge, ionic bonding, covalent bonding, hydrophobicity, hydrophilicity, and quantum mechanical tunneling, to the virtual exclusion of macro-scale effects such as turbulence and inertia.
The size scale of nanoscience and nanotechnology make them susceptible to quantum-based phenomena, leading to often counterintuitive results. Furthermore, the vastly increased ratio of surface area to volume opens new possibilities in surface-based science, such as catalysis.
Nanotechnology is already having a considerable impact on the field of electronics, where the drive towards miniaturization continues and transistor gate lengths of 65 nm are routinely fabricated in prototype circuits. The device density of modern computer electronics (i.e. the number of transistors per unit area) has grown exponentially, and this trend is expected to continue for some time (see Moore's law). However, both economics and fundamental electronic limitations prevent this trend from continuing indefinitely. Some see further development of nanotechnology outside of the semiconductor roadmap, and the hoped-for advent of molecular nanotechnology, as the next logical steps for continued advances in computer architecture, while others are less sanguine.
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