Nanometre
A nanometre (nm) is a unit of length in the metric system, equal to one billionth of a metre (10-9 m). It is one millionth of a millimetre (10-6 mm), or one thousandth of a micrometre (10-3 μm).
The nanometre is commonly used to measure dimensions at the atomic and molecular level. It is particularly important in nanotechnology, semiconductor manufacturing, and materials science. For perspective, a strand of human DNA is about 2.5 nanometres in diameter. Individual atoms are on the order of 0.1 to 0.3 nm in diameter.
The term "nanometre" is derived from the Greek word "nanos," meaning "dwarf." The prefix "nano-" is used in the International System of Units (SI) to denote a factor of 10-9.
Applications of nanometre-scale technologies and materials include:
- Electronics: Transistors and other electronic components are manufactured at the nanometre scale, allowing for increased performance and miniaturization of devices.
- Materials Science: Nanomaterials, such as nanoparticles and nanotubes, possess unique properties compared to their bulk counterparts, leading to applications in areas like reinforced composites, drug delivery, and sensors.
- Medicine: Nanoparticles can be used for targeted drug delivery, diagnostic imaging, and gene therapy.
- Optics: Nanomaterials can be engineered to manipulate light in novel ways, leading to applications in advanced displays, solar cells, and optical sensors.
Because the nanometre is so small, specialized techniques such as electron microscopy and atomic force microscopy are often required to visualize and manipulate structures at this scale. The precision required in working at the nanometre scale necessitates highly controlled environments and specialized equipment.