Shaping Thermal\nTransport and Temperature Distribution\nvia Anisotropic Carbon Fiber Reinforced Composites

With the ongoing electrification of vehicles, thermal\nmanagement\nis on everyone’s lips. To prevent overheating in electronic\nsystems, new design strategies for thermal dissipation are needed.\nThermally anisotropic materials enable targeted directional heat transport\ndue to their anisotropic thermal conduction. Laminates made of unidirectionally\naligned carbon fibers in a polymer matrix can be tailored regarding\ntheir in-plane anisotropy. Exposing the laminates to a temperature\ngradient reveals that the thermal transport is determined by their\nanisotropic properties. The corresponding heat flow can be visualized\nby IR thermography. The combination of anisotropic laminate discs\ninto composite materials, similar to building with toy bricks, enables\nprecise control of heat transport in the macroscopic composite materials.\nThus, we achieve control of heat flow at the level of the individual\ncomponents. In addition, we show that the orientation of anisotropy\nrelative to the temperature gradient is crucial to guide the heat\nflow selectively. We found that the ratio of thermal anisotropy, the\namount and arrangement of anisotropic components, and their positioning\nin the composite strongly influence heat transport. By combining all\nthese factors, we are able to locally control the heat flow in composites\nby creating materials to either dissipate heat or block heat transport.\nThe proposed concept can be extended to different shapes of building\nblocks in two or three dimensions.