Origami-geometry-enabled seaweed cultivation for scalable carbon sequestration in open oceans.

Seaweed aquaculture offers a scalable route to food production and marine carbon sequestration, yet expansion into open oceans is limited by strong currents that prevent stable attachment and destroy the low-velocity conditions needed for growth, while nutrient scarcity adds a further constraint. Existing platforms either rely on scarce offshore infrastructure or lack the geometric capacity to regulate local flow. Here we show that origami geometry can reshape local hydrodynamics to create substantially larger suitable growth volumes within a modular shell-core structure that simultaneously provides attachment surfaces and nutrient storage. Computational fluid dynamics demonstrated that a single unit under 2.0 m s-1 currents produced a suitable growth volume 17 times larger than a spherical reference; optimized multi-unit arrangements further increased per-unit volume 2.1-fold through cooperative wake interactions. Laboratory, lake, and open-ocean trials confirmed structural stability, and global mapping identified approximately 10,335 million hectares of potentially suitable waters. These results establish origami geometry as a design principle that enables scalable seaweed cultivation for carbon sequestration in open oceans.