Alignment engineering in thermal materials

Thermal management has become increasingly critical in a broad range of applications, including cooling electronic devices, regulating body temperature, harvesting solar energy, and so on. To achieve effective thermal management, thermal materials are essential platform that enables various thermal functions such as conduction, insulation, radiation, and absorption. However, it remains challenging to tune these properties in thermal materials by traditional mixing strategy. Alignment engineering has emerged as a promising approach for designing and fabricating thermal structures with extraordinary performance, but hasn’t been systematically summarized yet. In this review we summarize the recent progress in the emerging field of alignment-engineered thermal materials. The state-of-the-art alignment strategies are introduced, and various thermal materials, including alignment-engineered conductive, insulative, emissive, and absorptive materials, are discussed with emphasis on the correlations between alignment approaches and thermal functionalities, and the dynamic balance between ideal structure and practical engineering. Finally, we outline some perspectives on the challenges and opportunities for alignment engineering toward advanced thermal materials and practical applications.