Abstract

and materials or lack of scalability and vascular complexity of the fabrication approach. Here we show that the introduction of sacrificial fibers into woven preforms enables the seamless fabrication of 3D microvascular composites that are both strong and multifunctional. Underpinning the method is the efficient thermal depolymerization of catalyst-impregnated polylactide (PLA) fibers with simultaneous evaporative removal of the resulting lactide monomer. The hollow channels produced are high-fidelity inverse replicas of the original fiber’s diameter and trajectory. The method has yielded microvascular fiber-reinforced composites with channels over one meter in length that can be subsequently filled with a variety of liquids including aqueous solutions, organic solvents, and liquid metals. By circulating fluids with unique physical properties, we demonstrate the ability to create a new generation of biphasic pluripotent composite materials in which the solid phase provides strength and form while the liquid phase provides interchangeable functionality. Microvascular composite fabrication begins with the mechanized weaving of sacrifi cial fi bers into 3D woven glass