Abstract
The ideal electronics packaging for next-generation wearable devices and integrated circuits would be a flexible material with high thermal conductivity of a metal. We report a liquid-metal polyurethane composite (LiMPuC) with a thermal conductivity of 23.42 W m-1 K-1 while retaining extreme stretchability. The performance arises from interfacial-chemistry-guided ordering of the polyurethane matrix and improved liquid-metal wetting. By modulating hydrogen-bond donor/acceptor densities in the thermoplastic polyurethane and grafting –NH2 groups onto eutectic gallium–indium (EGaIn) droplets, we create anchored, reconfigurable interfaces that (i) increase matrix chain alignment and intrinsic heat transport and (ii) promote stable, strain-tolerant thermal near-percolation of the liquid metal. Under large tensile strain, these coupled effects preserve high conductivity and deliver a flexibility figure of merit > 100. This chemistry-to-microstructure pathway, linking hydrogen-bond engineering with LM surface functionalization, provides a general strategy for designing flexible, high-\(\kappa\) composites for advanced thermal management in emerging electronics.
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The source data underlying Figs. 2–4 and Supplementary Figs. 9, 15,16, 19, 21, 22, 25 are provided as a Source Data file. Other source data are provided with this paper and the Supplementary Information. The experimental data that support the findings of this study are also available from the corresponding author upon request. Source data are provided in this paper.
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Acknowledgements
Y.L. acknowledges support from the National Natural Science Foundation of China (52273029), the Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China (2021ZZ119), the Natural Science Foundation of Fujian Province for Distinguished Young Scholars (2023J06045), the Self-deployment Project Research Program of State Key Laboratory of Functional Crystals and Devices (GNJT-2025-ZD07), and the Self-deployment Project Research Program of Haixi Institutes, Chinese Academy of Sciences (CXZX-2023-JQ09).
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Y.L. conceptualized the idea. Y.L., G.J.S., and S.B. designed the experiments. X.L., J.W., M.H., R.X., J.H., W.L., and M.L. performed the experiments, with X.L., J.W., R.X., and Y.L. analyzing the data. Y.L., J.W., and X.L. developed and constructed the thermal measurement instrumentation. Y.L. and X.L. drafted the initial manuscript, and all authors contributed to the discussion of the results and provided feedback on the manuscript.
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Liu, X., Wen, J., Xu, R. et al. Flexible rubber with metal-like thermal conductivity achieved via hydrogen bonding engineering. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71056-0
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DOI: https://doi.org/10.1038/s41467-026-71056-0
