Microvascular Composites for Novel Thermal Management Devices

Living systems rely on pervasive vascular networks to enable a plurality of biological function, exemplified by natural composite structures 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. CU Aerospace, with team partners the University of Illinois at Urbana-Champaign (UIUC), North Carolina State University (NCSU), and Lockheed Martin, are utilizing a revolutionary microvascular technology developed at UIUC to build a composite counter-flow heat exchanger. This technology relies on 3D weaving of sacrificial fibers into a polymeric matrix, which are subsequently vaporized to obtain a uniform array of capillaries. By weaving these sacrificial fibers with a perpendicular array of carbon fibers and using computational modeling to optimize the design, this device can achieve good lateral thermal conductance while retaining very low axial conductance. Most Joule-Thomson heat exchangers are either metal finned-tube devices with limited surface area between the solid and gas streams, or etched-glass/silicon devices that allow relatively limited gas flow and cooling power. A micro-capillary array based heat exchanger offers the potential for both large surface area and large gas flow, with a manufacturing process that offers low-cost mass production.