Design and Thermal Performance of a Hinged Ultra-thin Flexible Vapor Chamber for Foldable Electronic Devices

As the trend toward device miniaturization and portability intensifies, foldable electronics have emerged as a pivotal innovation in the consumer electronics industry. However, increasing power densities and system integration impose stringent requirements on thermal management, rendering conventional solutions inadequate due to their rigidity and limited adaptability. Ultra-thin vapor chambers (UTVCs), which leverage two-phase heat transfer mechanisms, offer high effective thermal conductivity and compactness, but their typically rigid structures restrict their applicability in flexible systems, often resulting in mechanical fatigue and elevated interfacial thermal resistance. To overcome these limitations, this study proposes a hinged ultra-thin flexible vapor chamber (HUTFVC) interconnected via graphene film. The device incorporates a composite wick consisting of 2D copper mesh and 3D spiral woven mesh, achieving a total thickness of just 0.35 mm. Experimental results show that the HUTFVC attains an effective thermal conductivity of up to 2565.21 W/(m·K), approximately 6.4 times that of copper, under gravity-assisted conditions. Moreover, mechanical cycling tests confirm its durability through over 5000 folding cycles without structural degradation. These results demonstrate that the HUTFVC provides a high-performance, mechanically resilient, and integrable thermal solution for next-generation foldable electronics, with significant potential for engineering application and industrial deployment.