Microfactories

Microfactories are presumably a small dimension factory that is able to produce small dimension products. While this technology is currently experimental in the real world, they are mentioned in three instances in Metroid Prime series data.

The Logbook entry for Samus Aran's Gunship in Metroid Prime 2: Echoes and Metroid Prime 3: Corruption reveal that the Gunships in both games contain microfactories designed to produce ammunition. This explains how Samus is able to regenerate her Missile, Power Bomb and/or Beam Ammo within her Gunship. The microfactories do not, however, restore Ship Missile Ammunition in Corruption, which must be collected in the field from killed enemies or broken crates.

Unused, original log data in the internal files of the Metroid Prime 2: Echoes Bonus Disc mention Splitter Microfactories. These were contained within the "Steadfast" class Guardian (Quadraxis in the final game), which used them to generate Splitter class sentry drones (Quads in the final game). In the final game, Dark Quads are spawned separately from Quadraxis.