Friction and wear remain the primary modes for energy dissipation in moving mechanical components. Superlubricity is highly desirable for energy saving and environmental benefits. Macroscale superlubricity was previously performed under special environments or on curved nanoscale surfaces. Nevertheless, macroscale superlubricity has not yet been demonstrated under ambient conditions on macroscale surfaces, except in humid air produced by purging water vapor into a tribometer chamber. In this study, a tribological system is fabricated using a graphene-coated plate (GCP), graphene-coated microsphere (GCS), and graphene-coated ball (GCB). The friction coefficient of 0.006 is achieved in air under 35 mN at a sliding speed of 0.2 mm s-1 for 1200 s in the developed GCB/GCS/GCP system. To the best of the knowledge, for the first time, macroscale superlubricity on macroscale surfaces under ambient conditions is reported. The mechanism of macroscale superlubricity is due to the combination of exfoliated graphene flakes and the swinging and sliding of the GCS, which is demonstrated by the experimental measurements, ab initio, and molecular dynamics simulations. These findings help to bridge macroscale superlubricity to real world applications, potentially dramatically contributing to energy savings and reducing the emission of carbon dioxide to the environment.

中文翻译：

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石墨烯涂层表面实现宏观超润滑。

摩擦和磨损仍然是运动机械部件能量耗散的主要方式。超润滑对于节能和环境效益来说是非常理想的。宏观超润滑以前是在特殊环境下或在弯曲的纳米级表面上进行的。然而，宏观超润滑性尚未在环境条件下在宏观表面上得到证实，除了通过将水蒸气吹入摩擦试验室而产生的潮湿空气中。在这项研究中，使用石墨烯涂层板（GCP）、石墨烯涂层微球（GCS）和石墨烯涂层球（GCB）制造了摩擦学系统。在开发的 GCB/GCS/GCP 系统中，在 35 mN 的空气中，以 0.2 mm s-1 的滑动速度持续 1200 秒，摩擦系数达到 0.006。据了解，首次报道了环境条件下宏观表面的宏观超润滑性。宏观超润滑的机制是由于剥离的石墨烯薄片与GCS的摆动和滑动相结合，这通过实验测量、从头算和分子动力学模拟得到了证明。这些发现有助于将宏观超润滑与现实世界的应用联系起来，可能会极大地促进节能并减少二氧化碳向环境的排放。