Conductive patterned metal films bonded to compliant elastomeric substrates form meshes which enable flexible electronic interconnects for various applications. However, while bottom-up deposition of thin films by sputtering or growth is well-developed for rigid electronics, maintaining good electrical conductivity in sub-micron thin metal films upon large deformations or cyclic loading remains a significant challenge. Here, we propose a strategy to improve the electromechanical performance of nanometer-thin palladium films by in-situ synthesis of a conformal graphene coating using chemical vapor deposition (CVD). The uniform graphene coverage improves the thin film’s damage tolerance, electro-mechanical fatigue, and fracture toughness owing to the high stiffness of graphene and the conformal CVD-grown graphene-metal interface. Graphene-coated Pd thin film interconnects exhibit stable increase in electrical resistance even when strained beyond 60% and longer fatigue life up to a strain range of 20%. The effect of graphene is more significant for thinner films of < 300 nm, particularly at high strains. The experimental observations are well described by the thin film electro-fragmentation model and the Coffin-Manson relationship. These findings demonstrate the potential of CVD-grown graphene nanocomposite materials in improving the damage tolerance and electromechanical robustness of flexible electronics. The proposed approach offers opportunities for the development of reliable and high-performance ultra-conformable flexible electronic devices.

导电图案金属薄膜粘合到柔顺的弹性体基材上形成网格，从而为各种应用提供灵活的电子互连。然而，虽然通过溅射或生长的自下而上沉积薄膜对于刚性电子产品来说已经很成熟，但在大变形或循环负载下保持亚微米薄膜金属良好的导电性仍然是一个重大挑战。在这里，我们提出了一种通过化学气相沉积（CVD）原位合成保形石墨烯涂层来提高纳米薄钯膜机电性能的策略。由于石墨烯的高刚度和共形 CVD 生长的石墨烯-金属界面，均匀的石墨烯覆盖提高了薄膜的损伤容限、机电疲劳和断裂韧性。即使应变超过 60%，石墨烯涂层 Pd 薄膜互连也能表现出稳定的电阻增加，并且在应变范围达 20% 的情况下，疲劳寿命更长。对于 < 300 nm 的较薄薄膜，石墨烯的影响更为显着，特别是在高应变下。薄膜电碎裂模型和科芬-曼森关系很好地描述了实验观察结果。这些发现证明了 CVD 生长的石墨烯纳米复合材料在提高柔性电子产品的损伤容限和机电鲁棒性方面的潜力。所提出的方法为开发可靠且高性能的超顺应柔性电子设备提供了机会。