Huang Xuanyu, Xiang Xiaojian, Nie Jinhui, Peng Deli, Yang Fuwei, Wu Zhanghui, Jiang Haiyang, Xu Zhiping, Zheng Quanshui
Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China.
Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China.
Nat Commun. 2021 Apr 15;12(1):2268. doi: 10.1038/s41467-021-22371-1.
Miniaturized or microscale generators that can effectively convert weak and random mechanical energy into electricity have significant potential to provide solutions for the power supply problem of distributed devices. However, owing to the common occurrence of friction and wear, all such generators developed so far have failed to simultaneously achieve sufficiently high current density and sufficiently long lifetime, which are crucial for real-world applications. To address this issue, we invent a microscale Schottky superlubric generator (S-SLG), such that the sliding contact between microsized graphite flakes and n-type silicon is in a structural superlubric state (an ultra-low friction and wearless state). The S-SLG not only generates high current (210 Am) and power (7 Wm) densities, but also achieves a long lifetime of at least 5,000 cycles, while maintaining stable high electrical current density (~119 Am). No current decay and wear are observed during the experiment, indicating that the actual persistence of the S-SLG is enduring or virtually unlimited. By excluding the mechanism of friction-induced excitation in the S-SLG, we further demonstrate an electronic drift process during relative sliding using a quasi-static semiconductor finite element simulation. Our work may guide and accelerate the future use of S-SLGs in real-world applications.
能够有效将微弱且随机的机械能转化为电能的小型化或微尺度发电机，在为分布式设备的供电问题提供解决方案方面具有巨大潜力。然而，由于摩擦和磨损普遍存在，迄今开发的所有此类发电机都未能同时实现足够高的电流密度和足够长的使用寿命，而这对于实际应用至关重要。为解决这一问题，我们发明了一种微尺度肖特基超润滑发电机（S-SLG），使得微米级石墨薄片与n型硅之间的滑动接触处于结构超润滑状态（超低摩擦且无磨损状态）。该S-SLG不仅能产生高电流（约210 Am）和高功率（约7 Wm）密度，还能实现至少5000次循环的长寿命，同时保持稳定的高电流密度（约119 Am）。实验过程中未观察到电流衰减和磨损，表明S-SLG的实际持久性是持久的或几乎是无限的。通过排除S-SLG中摩擦诱导激发的机制，我们利用准静态半导体有限元模拟进一步证明了相对滑动过程中的电子漂移过程。我们的工作可能会指导并加速S-SLG在实际应用中的未来使用。
