Biotron was created by Takara Toys in 1975 as a bridge between their Henshin Cyborg and Microman toy lines. Initially called Robotman in Japan, he was renamed Biotron when Mego bought the rights to produce the Microman toy line in the United States in 1976. Writer Bill Mantlo fleshed out a back story and a personality for Biotron during his initial run on Marvel's Micronauts series. Artist Michael Golden drastically scaled the character down in size but generally remained faithful to the original toy design. In Micronauts issue #26 Biotron was destroyed during a battle with Baron Karza and Hydra. Much later, all of Biotron's memories were downloaded into a giant spaceship, modeled off of Biotron's original appearance, called The Bioship. In Micronauts issue #58 Biotron was again restructured as a slightly larger than man sized roboid until he was again destroyed in Micronauts The New Voyages #4. Biotron was rebuilt yet again in Micronauts The New Voyages #9 and series artist Kelley Jones took the opportunity to give him a sleeker more streamlined redesign that had little resemblance to the original toy.
Biotron was created by the Homeworld engineers to serve as the eyes and ears for Commander Arcturus Rann during his long hypersleep. Their mission was to spend 1000 years exploring the Microverse, and during that time the two became psychically connected. Upon completion of their mission, Biotron and Commander Rann returned to Homeworld to find it under the oppression of a totalitarian regime, led by Rann's former science teacher, Baron Karza. Banding together with several other rebels and outcasts, Rann and Biotron formed The Micronauts, and dedicated their lives to fighting Karza's rule.