Nanotechnology
From Memory Alpha, the free Star Trek reference
Nanotechnology was a field of science and technology involving devices so small that the naked eye could not see them.
The Borg Collective was infamous for their use of nanotechnology to advance their goals, specifically assimilating new members and technologies with nanoprobes. (VOY: "Scorpion")
The Federation Starfleet also commonly used nanotechnology, such as in isolinear circuitry. In 2366, Wesley Crusher was experimenting with nanites, small robotic devices in the field of nanotechnology. (TNG: "Evolution")
Major Kira Nerys once delayed Vedek Winn's ship and claimed it was to inspect for nanotechnology. (DS9: "The Collaborator")
