Three-dimensional microvascular fiber-reinforced composites.

Living systems rely on pervasive vascular networks to enable a plurality of biological function in both soft and hard tissue. Extensive vasculature in composite structures, such as osseous tissue in bone and tracheary elements in trees, exemplify natural materials that are lightweight, high-strength, and capable of mass and energy transport. In contrast, synthetic composites possess high strength-to-weight ratios but lack the dynamic functionality of their natural counterparts. The creation of microvascular networks in composites by methods that are fully compatible with current composite manufacturing processes remains an unmet challenge. Fabrication approaches such as laser micromachining, [ 1–3 ] soft lithography, [ 4–7 ] electrostatic discharge, [ 8 ] fugitive inks, [ 9–11 ] sugar and polyethylene fibers, [ 12 , 13 ] and hollow glass fibers [ 14–17 ] produce microvascular structures, but none of these are suitable for rapid, large-scale production of fiber-reinforced composites with complex vasculatures due to either incompatibility with existing composites manufacturing methods