Nanotechnology, shortened to “nanotech,” is the study of the control of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller, and involves developing materials or devices within that size. Nanotechnology is very diverse, ranging from novel extensions of conventional device physics, to completely new approaches based upon molecular self-assembly, to developing new materials with dimensions on the nanoscale, even to speculation on whether we can directly control matter on the atomic scale.
One nanometer (nm) is one billionth of a meter. By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12-0.15 nm.
Two main approaches are used in nanotechnology. In the “bottom-up” approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. In the “top-down” approach, nano-objects are constructed from larger entities without atomic-level control.
Molecular nanotechnology (or molecular manufacturing) would involve manipulating single molecules in finely controlled, deterministic ways. This is more theoretical than the other subfields and is beyond current capabilities. It is especially associated with the concept of a molecular assembler, which can produce a structure or device atom-by-atom. Manufacturing in the context of productive nanosystems is not related to the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles.
Other speculative areas include nanorobotics and programmable matter based on artificial atoms.
Health and societal concerns
A number of serious concerns have been raised about what effects and risks the increased use of nanotechnology could pose for society, and what action if any is appropriate to mitigate these risks.
A study found that when rats breathed in nanoparticles, the particles settled in the brain and lungs, which led to significant increases in biomarkers for inflammation and stress response. A major study published more recently in Nature Nanotechnology suggests some forms of carbon nanotubes – a poster child for the"nanotechnology revolution” – could be as harmful as asbestos if inhaled in sufficient quantities.
Calls for tighter Regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology.
The Center for Responsible Nanotechnology suggests that new developments could result in, among other things, untraceable weapons of mass destruction, networked cameras for use by the government, and weapons developments fast enough to destabilize arms races. One area of concern is the effect that industrial-scale manufacturing and use of nanomaterials would have on human health and the environment, as suggested by nanotoxicology research. Groups such as the Center for Responsible Nanotechnology have advocated that nanotechnology should be specially regulated by governments for these reasons.
Some counter that overregulation would stifle scientific research and the development of innovations which could greatly benefit humanity. Other experts have testified that successful commercialization depends on adequate oversight, risk research strategy, and public engagement.
The Center for Responsible Nanotechnology