In vitro biomimetic modeling of physio-logical structures bridges the gap between 2D in vitro culture and animal models. Lumens (tubular structures) are ubiquitous in vivo, being present in blood vessels, mammary ducts, and the lymphatic system. A method 'LumeNEXT' is presented here that allows the fabrication of 3D embedded lumens where size, structure, distance, and configuration can be controlled using standard poly-dimethylsiloxane micromolding methods.