Huang Xuanyu, Xiang Xiaojian, Li Chuang, Nie Jinhui, Shao Yifan, Xu Zhiping, Zheng Quanshui
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, China.
Nat Commun. 2025 Jan 8;16(1):493. doi: 10.1038/s41467-024-55078-0.
Micro actuators are widely used in NEMS/MEMS for control and sensing. However, most are designed with suspended beams anchored at fixed points, causing two main issues: restricted actuated stroke and movement modes, and reduced lifespan due to fatigue from repeated beam deformation, contact wear and stiction. Here, we develop an electrostatic in-plane actuator leveraging structural superlubric sliding interfaces, characterized by zero wear, ultralow friction, and no fixed anchor. The actuator features a micro-scale graphite flake in structural superlubric contact with silicon dioxide tracks, reducing friction from edge defects. Using the charge injection method, the structural superlubric actuator not only achieves a maximum relative actuation stroke of 82.3% of the flake size by applying voltage to buried electrodes-3.4 times larger than previously reported, but also enables controllable reciprocating actuation by adjusting the form of the bias voltage. Additionally, no visible wear was observed at the structural superlubric interface after over 10,000 sliding cycles, indicating robust reliability. Our work presents a design concept for micro actuators with high performance and durability, potentially guiding the development of many structural superlubric micro-devices.
微执行器在纳米机电系统/微机电系统中被广泛用于控制和传感。然而，大多数微执行器的设计是带有固定在固定点的悬梁，这会导致两个主要问题：驱动行程和运动模式受限，以及由于梁的反复变形、接触磨损和黏附引起的疲劳导致寿命缩短。在此，我们开发了一种利用结构超润滑滑动界面的静电平面内执行器，其特点是零磨损、超低摩擦且无固定锚点。该执行器的特征是一个微尺度的石墨薄片与二氧化硅轨道形成结构超润滑接触，减少了边缘缺陷产生的摩擦。使用电荷注入方法，这种结构超润滑执行器不仅通过向埋入电极施加电压实现了最大相对驱动行程为薄片尺寸的82.3%，比之前报道的大3.4倍，而且还能通过调整偏置电压的形式实现可控的往复驱动。此外，在超过10000次滑动循环后，在结构超润滑界面未观察到明显磨损，表明其可靠性强。我们的工作提出了一种高性能和耐用性的微执行器设计概念，可能会指导许多结构超润滑微器件的发展。
