From Fiber Bundles to Architected Membranes: Triply Periodic Minimal Surface Architectures for Biohybrid Artificial Lungs.

Artificial lung systems rely almost exclusively on hollow fiber membrane (HFM) bundles, where gas exchange is constrained by heterogeneous flow distribution and thrombogenic blood-material interfaces. Here, we introduce an architecture-driven design framework for artificial lungs based on additively manufactured triply periodic minimal surface (TPMS) membranes. In contrast to discrete fiber bundles, TPMS membranes form continuous three-dimensional architectures that simultaneously regulate perfusion pathways, diffusion interfaces, and blood-material interactions. Computational fluid dynamics and multiphysics transport simulations reveal that membrane architecture governs gas exchange through coupled effects of membrane thickness, unit cell size, and three-dimensional flow topology. Optimized TPMS architectures achieved on average up to ∼88% higher oxygen transfer rates across the investigated flow regime compared to conventional HFM while enabling substantially more homogeneous flow fields and reduced stagnation zones. Experimental screening identifies polydimethylsiloxane-based printable elastomers compatible with thin gas-permeable membranes and endothelial functionalization. The biohybrid endothelial interface mitigates thrombogenic interactions, while maintaining gas transport. Computed tomography-derived implant geometries demonstrate the feasibility of translating architected membrane systems into anatomically integrated artificial lungs. Together, these results establish a new design paradigm for artificial lungs, in which membrane architecture becomes the primary determinant of gas transport, flow distribution, and hemocompatibility.