Bio-inspired microvascular exchangers employing circular packing – synthetic rete mirabileElectronic supplementary information (ESI) available: Design of packing patterns. Exchange unit fabrication. COMSOL mass and heat transfer modeling. CO2-MEA reaction mechanism. Mass and heat transfer experimental details. Fluorescent temperature measurement probe information. Heat transfer calculations. Channel distance correlations. See DOI: 10.1039/c4mh00120f

Natural systems employ microvascular exchangers with circular packing for both heat and mass transfer that closely conform to the compact, packing of circles of two diameter. Mathematical descriptions of these systems exist, but have rarely been studied in three dimensions for their exchange properties. We focus on four close packed patterns: “Hexagonal” “Dodecagonal”, “Squarer”, and “Double Squarer”. While two of these patterns have natural analogs, the others are abiological. We compare computationally and experimentally the mass and heat transfer characteristics of these various patterns. Intriguingly the “Double Squarer” pattern, had the highest transfer rates within our fabrication constraints.