Non-conformal thermal cloak metamaterial by continuous metal fiber embedded 3D printing

Thermal metamaterials represent a promising avenue for controlling and manipulating heat flow, obtaining typical devices such as thermal cloaks, thermal rotators, and thermal concentrators. However, there is still a limited theoretical and experimental study of nonconformal geometric thermal metadevices accessible due to design and fabrication challenges. Prominent traditional fabrication methods, such as laminating and layer-by-layer assembly, mold-based casting, and combining processes with 3D printing and wire-cutting methods, have consistently presented challenges in fabricating complex components with high structural integrity and mechanical performance. Therefore, a novel continuous metal fiber-embedded 3D printing approach was proposed in this research to support the design and fabrication of a nonconformal thermal cloak metamaterial. The design is based upon conformal discrete theory (CDT) to simplify the anisotropic thermal conductivity tensors. Subsequently, the design was demonstrated by using a continuous constant metal wire of 0.3 mm in diameter after iterative parametric analysis with successful competitive potential for thermal cloaking effect and temperature behavior at the stealth area. The study showcases the simulation and experimental implementation of cloaking functionalities, offering guidance for the design and manufacturing of nonconformal thermal metamaterials by continuous metal fiber-embedded 3D printing that have potential applications in various fields, such as heat shielding, temperature regulation, heat spreaders for electronic devices, and aircraft.