Mechanical–Thermal Coupling in Polymer Nanocomposites: From Interfacial Engineering to Cutting‐Edge Applications

ABSTRACT Polymer nanocomposites, fabricated by incorporating nano‐fillers into polymer matrices, are critical for applications in new energy, integrated circuits, flexible electronics, and soft robotics. These fields demand materials that simultaneously offer robust load‐bearing capabilities, efficient thermal management, and precise thermal responsiveness. Crucially, the internal mechanical and thermal fields within these materials interact, creating significant mechanical–thermal coupling effects—specifically where mechanical deformation alters thermal transport properties. This is particularly critical for nano‐fillers, as at least one dimension is less than 100 nm, thereby generating a prominent interface effect. However, a systematic understanding of the mechanisms through which mechanical–thermal coupling influences material properties remains limited, thereby restricting the full potential of these high‐performance materials. Here, we examine the mechanical–thermal coupling mechanisms in polymer nanocomposites. We systematically discuss how key factors—including interfacial properties, filler characteristics, and microstructure—dictate these coupling behaviors. Furthermore, we comprehensively summarize the mechanisms by which stress and strain regulate thermal conductivity, alongside strategies for the synergistic optimization of mechanical and thermal properties. This review provides theoretical insights essential for enhancing the reliability of high‐end chips, improving the thermal stability of flexible electronics, and strengthening the environmental adaptability of soft robots.