Nanotechnology is an emerging field of research and development dedicated to increasing control over material structures of nanometre size (0.1 to 100nm). The prefix "nano" from a Greek word meaning "dwarf denotes a one billionth part. A nanometer is equal to one billionth of a meter (10~(-9) m). In comparison the limit of visibility for the unaided human eye is around 10~4 m. Nano-objects (1 to 100 nanometres) are therefore intermediate in size between molecules and bulk materials. Nanotechnology, according to the National Nanotechnology Initiative (NNI), is defined as utilisation of structures with at least one dimension of nanometre size for the construction of materials, devices or systems with novel or significantly improved properties due to their nano-size. Applications include solid-state, bio-, chemical and measurement technologies that converge "top-down" and "bottom-up" to the nanoscale. The concept of nanotechnology is however not new, having been adopted by Taniguchi in 1974 when he defined the critical dimensions and tolerances in technology. Hence nanotechnology is part of the evolution of machining accuracy, with no differences from traditional fields of science or engineering except in size. Today nanotechnology consists of four major fields: nanoelectronics, nanomaterials, molecular nanotechnology and nanoscale-resolution microscopy.
展开▼
