The gel packs were a major component of the bio-neural circuitry, which was a hybrid organic-electronic computer system. The packs contained neural fibers surrounded in a blue gel with metallic interfaces on the top and bottom. They helped store more information and operated at faster speeds than isolinear circuitry.
The fibers in an individual gel pack were capable of making billions of connections, thus generating an incredibly sophisticated and responsive computing architecture. This kind of organic circuitry allowed computers to "think" in very similar ways to living organisms; by using "fuzzy logic", they could effectively operate by making a "best guess" answer to complex questions rather than working through all possible calculations. This was due in part to the inherent ability of organic neural systems to correlate chaotic patterns that eluded the capacities of conventional hardware.
The USS Voyager was one of the first starships equipped with the technology. (VOY: "Caretaker") Gel packs could not be replicated. (VOY: "Learning Curve") Voyager stored their spare gel packs in engineering locker Gamma 5. (VOY: "Renaissance Man")
- They were infected with a virus within bacteria due to cheese created by Neelix. (VOY: "Learning Curve")
- A gel pack in the mess hall was infected with a macrovirus, and led to an outbreak when it ruptured. (VOY: "Macrocosm")
- During a voyage through a Mutara-class nebula, the gel packs began to fail due to subnucleonic radiation. (VOY: "One")
Gel packs could be modified by injecting chroniton-infused serum into the packs in order to return a ship caught in numerous temporal periods, such as caused by a temporal anomaly, to a single temporal period. This process returned the ship to a few seconds before the anomaly occurred. (VOY: "Shattered")
When Overlookers kidnapped Captain Kathryn Janeway, The Doctor was forced to steal gel packs by posing as Lieutenant B'Elanna Torres. However when Janeway was rescued by Lieutenant Tom Paris and Lieutenant Commander Tuvok, the gel packs were returned to Voyager. (VOY: "Renaissance Man")