Here we draw attention to the development of smart materials with embedded
vasculatures that provide multiple functionality: volumetric cooling, self-healing, mechanical
strength, etc. Vascularization is achieved by using tree-shaped (dendritic) and grid-shaped flow
architectures. As length scales become smaller, dendritic vascularization provides dramatically
superior volumetric bathing and transport properties than the use of bundles of parallel
microchannels. Embedded grids of channels provide substantially better volumetric bathing when
the channels have multiple diameters that are selected optimally and put in the right places. Two
novel dendritic architectures are proposed: trees matched canopy to canopy, and trees that alternate
with upside down trees. Both have optimized length scales and layouts. Flow architectures are
derived from principle, in accordance with constructal theory, not by mimicking nature.