The idea of “utility fog” dates back to an Old Terran idea for replacing vehicular safety restraints with a cloud of floating micro-machines that could interlock into an impromptu harness when needed. Later thinkers imagined using such machines to form tools or even perform open-air nanofabrication. As it turned out though, the vacuum chamber proved impossible to do without, but the potential for using microswarms as manipulatory tools was still worth exploration and the present-day Federation developed four broad classes of “utility bots” that are still in common use.
U-Fog: The “classic” form of U-Bot, these microbots are fine enough to be carried by a small breeze or lock together temporarily into microscopic propellers or sails for guided motion. These micro-motors cannot propel an object of any significant density in gravity, but they can form grapples, cushions, or momentary barriers capable of arresting motion. In a pressurized microgravity environment they can move dense objects or adhere a person’s feet to a surface, simulating gravity to an extent. In vacuum they are, of course, next to useless without air to carry them.
U-Water: Microbots suspended in liquid, this variety of U-Bot exhibits less mobility but more “strength” than fog. These bots can also exploit the surface tension of the liquid they’re suspended in to extend their area of effect much further than an equivalent volume of U-Fog. Usually the bots are concentrated in a relatively small volume of liquid for storage and then poured into a local source of fluid, even a natural pond or lake. While U-Water can’t perform nanofabrication without a vacuum chamber it is popular for repair work and macro-assembly, it can even seal injuries in first aid. In gravity the pool of U-Water must remain in contact with the ground or floor, but it can “reach up” or “climb” vertical surfaces to some extent. In microgravity U-Water tends to resemble a giant amoeba, reaching out pseudopods.
U-Sand: The largest variety of U-Bot, U-Sand components are on the scale of grains of sand and usually packed so densely that their swarms are visible to the naked eye. Small amounts may be used to form metamorphic tools that change shape at a moment’s notice, large amounts may even form temporary buildings. However, they are primarily used for excavation and construction, a swarm of U-Sand can grind away particles from sheer bedrock and reform the grains into concrete blocks. This process is slower than conventional construction but many spacers find it more practical to transport a few cubic meters of U-Sand than excavators and mixers. Some versions of U-Sand contain specialized bots with molecular assembly attachments and others that can lock together tightly enough to form a vacuum chamber, creating a field nanofabricator.
Energetic Bots: The original conception of Utility Fog imagined that the bots would be constructed from synthetic diamond. However, some critics of the idea pointed out that even crystalized, a cloud of what amounted to carbon dust would be extremely flammable. The concept was quickly revised to employ non-flammable corundum instead, but the original idea lived on in “Energetic” U-Bots or “E-Bots”. E-Bots can be patterned after any form of U-Bot and perform the same functions, provided an atmosphere deprived of oxygen, and carbon is cheaper than aluminum, but they are most famously weaponized. While any form of U-Bot can be used as a weapon in some manner, the spectacle from the combustion of E-Bots has lead many planetary governments to restrict them more heavily than corundum U-Bots.
Technomages: All but the most basic U-Bot configurations require a BCI to control. With mental commands U-Bots can rearrange themselves into any shape the user can imagine, within physical limits. Given that implants were already required to make the most effective use out of them, it was no surprise when somebody had the idea of installing U-Bot reservoirs in their own bodies. People with such reservoir implants often imagine themselves recreating the feats of wizards from fantasy novels, hence the moniker of “techno-mage”.
Cytoran, the Outworld of monsters and augmented heroes, has a fair number of Technomage Venturists who believe they are working real magic.
Technomage implants are typically installed in a limb, replacing most of the soft tissue between the bones of a forearm or lower leg and substituting the muscles with more compact synthetics. There are two general varieties of implant, reservoirs simply hold a quantity of U-Bots produced by an external device while fabbers contain a miniaturized nanofabricator specialized to produce one variety of U-Bot. Technomages with fabber implants will usually refer to themselves using one of the four elements of Ancient European proto-chemistry, “air mages” have U-Fog fabbers, “fire mages” will produce E-Bots, etc.
Cytoran’s Emissary distributes U-Bots through the temples dedicated to them and their Bureau Directors. Most of their priests have UBIs that can call upon the U-Bots stored in the temple whenever they’re on the grounds while Venturist priests get reservoir implants to use them in the field. Fabber implants are allowed, grudgingly, on the condition that the natives cannot understand how they work. However, technomages with fabbers, or “sorcerers”, are widely distrusted by the priesthood and the general public.