Sun Taotao, Wu Zhanghui, Li Zhihong, Zheng Quanshui, Lin Li
Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
Sensors (Basel). 2019 Aug 5;19(15):3431. doi: 10.3390/s19153431.
Structural superlubricity (SSL) is a state of nearly zero friction and zero wear between two directly contacted solid surfaces. Recently, SSL was achieved in mesoscale and thus opened the SSL technology which promises great applications in Micro-electromechanical Systems (MEMS), sensors, storage technologies, etc. However, load issues in current mesoscale SSL studies are still not clear. The great challenge is to simultaneously measure both the ultralow shear forces and the much larger normal forces, although the widely used frictional force microscopes (FFM) and micro tribometers can satisfy the shear forces and normal forces requirements, respectively. Here we propose a hybrid two-axis force sensor that can well fill the blank between the capabilities of FFM and micro tribometers for the mesoscopic SSL studies. The proposed sensor can afford 1mN normal load with 10 nN lateral resolution. Moreover, the probe of the sensor is designed at the edge of the structure for the convenience of real-time optical observation. Calibrations and preliminary experiments are conducted to validate the performance of the design.
结构超润滑（SSL）是两个直接接触的固体表面之间几乎零摩擦和零磨损的一种状态。最近，在中尺度上实现了SSL，从而开启了SSL技术，该技术有望在微机电系统（MEMS）、传感器、存储技术等领域得到广泛应用。然而，当前中尺度SSL研究中的负载问题仍不明确。巨大的挑战在于同时测量超低剪切力和大得多的法向力，尽管广泛使用的摩擦力显微镜（FFM）和微摩擦计分别可以满足剪切力和法向力的要求。在此，我们提出一种混合双轴力传感器，它能够很好地填补FFM和微摩擦计能力之间的空白，用于介观SSL研究。所提出的传感器能够承受1mN的法向负载，横向分辨率为10 nN。此外，传感器的探头设计在结构边缘，便于实时光学观察。进行了校准和初步实验以验证设计的性能。
