Recent advances in preparation and application of flexible thermally conductive elastomer films

Abstract

The growing demand for flexible electronics, on-chip cooling, and personal thermal management has driven the development of soft thermally conductive films that combine efficient heat transfer with mechanical compliance. This review summarizes recent advances in these materials, focusing on strategies to enhance thermal conductivity without sacrificing flexibility—such as rational filler selection, hierarchical microstructure design, and optimized interface engineering. We systematically analyze the properties of major elastomeric matrices and a range of functional fillers, including graphene, boron nitride, carbon nanotubes, MXene, and metallic nanowires, highlighting how surface functionalization, orientation control, and low-resistance interfacial coupling facilitate continuous phonon transport. Various fabrication approaches, from blending and coating to self-assembly and printing are evaluated in terms of their ability to balance thermal performance with mechanical compliance and environmental durability. Emerging applications in foldable heat sinks and conformal thermal interface for wearable devices are discussed, along with current challenges such as high interfacial thermal resistance and the trade-off between thermal and mechanical properties. The review concludes with perspectives on future research directions, including self-healing, ultra-flexible, and multifunctional thermal films.