Energy-efficient Conformal Mold Cooling Using Additively Manufactured Microcellular Thermal Metamaterials

Additive manufacturing (AM) has recently gained attention for its ability to fabricate conformal cooling channels with complex internal geometries, owing to its high design flexibility. This study proposes a design strategy based on lattice-type microcellular structures to improve energy efficiency in conformal mold cooling. Microlattice-based cellular cooling channels with varying strut diameters were designed to enhance heat transfer performance, while cellular inlet/outlet tubes were introduced to improve thermal insulation and minimize heat leakage. A series of configurations combining different tubes and channel designs was numerically investigated in terms of thermal, structural, and fluidic performance, and compared with conventional circuit-type straight and curved channels. Among the tested design candidates, a strut diameter of 0.6 mm was identified as optimal, providing a favorable balance between thermal insulation and structural integrity. Mold heating experiments comprehensively validated the simulation results, demonstrating that the cellular tubes reduced surface temperatures by over 20% compared to solid tubes, while the cellular cores increased heating rate and improved temperature uniformity across the mold surface. Notably, the combined use of a cellular core and cellular tubes achieved the lowest energy consumption (2.0 ± 0.19 Wh) and fastest thermal response, demonstrating superior overall performance. These findings highlight the potential of microcellular thermal metamaterials for advanced conformal cooling applications, including injection molding and die casting, enabling both enhanced heat transfer and energy savings in high-performance mold designs.