The Barrow Scale classifies civilizations by their capacity for inward miniaturization of technology — micro/nano-scale engineering — complementing the outward-facing kardashev-scale. While the Kardashev scale measures energy use at planetary, stellar, and galactic levels, the Barrow scale tracks mastery of progressively smaller structures.
Vidal et al. (2026) argue in their comprehensive technosignatures review that both scales should inform seti search strategies, since detectable signatures may arise from miniaturized engineering as well as megastructures. See src-technosignatures-review-2026-05.