Seven of Nine
The Borg are a major source of technological upgrades conducted on "Voyager". Cargo bay 2 is equipped with several Borg alcoves when Captain Janeway forms an alliance with the Borg and several Borg are forced to work aboard "Voyager" during the alliance. Seven of Nine and Harry Kim build an astrometrics lab from scratch with Borg-enhanced sensors, knowledge of which Seven of Nine retained from the Borg. Additionally, the crew designed and built the "Delta Flyer" support craft at the behest of the character Tom Paris later in the series.