|There is more information available on this subject at Nanotechnology on the English Wikipedia.|
Nanotechnology, often shortened to nanotech, is a field of technology involving the manipulation of matter on extremely small scales.
Humanity first began developing nanotechnology around the turn of the 21st century. The technology saw widespread use by the 26th century, serving as a general-purpose technology on almost all industries. The term "nanotechnology" was coined by the Japanese scientist Norio Taniguchi and popularized by K. Eric Drexler.
Humanity, principally the United Nations Space Command, utilizes nanotechnology for several purposes. Nanoreagent hydrocarbots are a suspension of nanomachines that convert carbon-heavy matter into usable fuel for the UNSC's internal combustion power plants, including the hydrogen-injected internal combustion engines used by the M12 Force Application Vehicle and the M274 Ultra-Light All-Terrain Vehicle.
In addition, various nanoscale materials such as carbon nanofibers (primarily carbon nanotubes) have become standard in construction. Due to its great durability and strength, carbon nanotubes allows the construction of enormous structures which would be impossible using conventional materials, such as space elevators. Carbon nanotubes are also used to construct vehicle tires, such as those of the M12 Warthog FAV. Possessing single-unit nanotube skeletons, the tires perform similar to traditional inflatable tires while being virtually unbreakable.
Other types of nano-fibers are utilized in special military training garments, working in conjunction with tactical training rounds. These fibers respond to TTR paint by becoming rigid and immobile, thus preventing a struck body part from moving.
Nanomachines are also used in conjunction with MJOLNIR armor systems. As of 2552, the UNSC had developed nanotechnology designed to perform repairs on MJOLNIR armor while its Spartan occupant rested in cryo-sleep. Given enough time and in the hands of a capable "smart" AI, these nanomachines were capable of completely overhauling a suit. While the Charon-class light frigate Forward Unto Dawn drifted through space for four years, the AI Cortana used nanomachines to upgrade and redesign John-117's MJOLNIR Mark VI armor. A similar form of nanotechnology was incorporated into the MJOLNIR Mark VII, allowing the suit to repair and upgrade itself autonomously during cryo-sleep. This feature was presumably carried over to the MJOLNIR [GEN2].
The Huragok are an example of the Forerunners' mastery of nanotechnology. Huragok are synthetic organisms, having no true tissues or organs but instead being composed entirely of nano-mechanical surrogates. Their tentacles are equipped with microscopic cilia, capable of splitting apart to manipulate objects on extremely small scales. Certain Forerunner installations, such as Shield World 006, contained special touch-panels that could interact on a nano-scale with Huragok cilia.
Certain Forerunner devices are capable of assembling objects out of raw materials, rearranging matter on a molecular or atomic scale. Design seeds could manufacture entire spacecraft on-site using only raw materials from the surrounding environment, and Promethean Watchers can similarly "conjure" new Crawlers simply by using raw materials present in an area of ground.
While few other examples of Forerunner nanotechnology are known to exist, their level of technological advancement would imply that most of their technology involved some form of nanotech.