Seaweed farming has long been recognized as a nature-based climate solution, but expanding it into the open ocean has proven difficult due to strong currents and scarce nutrients. A new study published on 28 September 2026 in Environmental Science and Ecotechnology presents a modular, origami-inspired system that could overcome these barriers, potentially enabling large-scale seaweed cultivation for carbon sequestration and other products.
Researchers at Zhejiang University, with collaborators at Guizhou University and the Ningbo Innovation Center, developed the Seaweed Origami-inspired Aquaculture System (Seaweed OAS). The design uses a shell-core structure to slow local flow, provide attachment surfaces, and store slow-release nutrients. In simulations, a single unit under 2.0 m/s currents produced a suitable growth volume 17 times larger than a spherical reference, and optimized six-unit arrays increased per-unit suitable volume by 2.1-fold. Laboratory, lake, and open-ocean trials in the Philippine Trench region confirmed stability, and global mapping identified 10,335 million hectares—28.5% of the global ocean—as potentially suitable.
The geometry is the breakthrough. Inspired by the traditional Chinese huiwen (fret) pattern, the researchers folded flat panels into a 25-sided variant pentagonal unit. Twelve units assemble into a dodecahedron-like shell. The dimensionless scaling ratio φ = a/R controls folding, with an optimal single-unit design at φ = 0.36. At 2.0 m/s inflow, it produced 2,607.7 cm³ of suitable growth volume, and the best single-unit result reached 2,791.6 cm³. Suitable growth was defined as streamwise velocity ≤0.5 m/s. In a six-unit Hexagon 2 layout with 0.35 m spacing, total suitable volume reached 33,210.3 cm³ at 2.0 m/s, or 5,535.1 cm³ per unit, 2.1 times an isolated unit. The modules were 3D-printed with polylactic acid (PLA) and water-soluble polyvinyl alcohol (PVA) supports. Compression tests gave a minimum peak load of 11,693 N versus a predicted peak drag of 39.9 N, a safety factor of 293.
Macroalgae contribute roughly 1.5 petagrams of carbon to global annual net primary production, and farm sediments can bury about 1.87 ± 0.73 tons of carbon dioxide equivalent per hectare per year—about twice the rate of adjacent non-farmed areas. Yet open-ocean expansion is limited by strong currents that prevent stable attachment and destroy the low-velocity conditions needed for growth. Nutrients such as nitrogen, phosphorus, and dissolved iron are too dilute for large-scale cultivation. Existing platforms either depend on scarce offshore infrastructure or cannot regulate local flow. The Seaweed OAS addresses these challenges by creating quiet microhabitats where seaweed can attach and grow, while storing slow-release nutrients. Cooperative wake interactions in the optimized hexagonal array let upstream units shield downstream units, increasing suitable growth volume per unit.
The authors caution that long-term cultivation outcomes, deep-ocean carbon storage, and the ecological effects of material degradation remain unverified and require field study. If validated over longer deployments, the Seaweed OAS could support open-ocean seaweed cultivation for food, feed, biomaterials, and carbon sequestration. Its modular shell-core design may be deployed without existing offshore infrastructure, and connection modules with controllable degradation could eventually let the system break apart so carbon-rich biomass sinks to the deep ocean for long-term storage. Global suitability mapping suggests vast potential across marine areas, though shipping lanes, ice cover, temperature, nutrient ratios, flow speed, and marine protected areas must guide siting. The authors call for long-term offshore trials to quantify seaweed growth, structural durability, material ecotoxicity, and the fate and persistence of sequestered carbon. The study was published with DOI 10.1016/j.ese.2026.100769.
