Friction and Pull-Off Forces on Submicron-Size Asperities Measured in High-Vacuum and in both Dry and Humid Nitrogen at Atmospheric Pressure
Friction and Pull-Off Forces on Submicron-Size Asperities Measured in High-Vacuum and in both Dry and Humid Nitrogen at Atmospheric Pressure
复制标题
在高真空以及大气压下干氮和湿氮中测量的亚微米级粗糙体的摩擦力和拉脱力
DOI：
10.1143/jjap.43.4506
复制
发表时间：
1998
影响因子：
1.5
通讯作者：
Y. Ando
中科院分区：
文献类型：
--
作者：
Y. Ando
利用聚焦离子束在硅衬底上制备了具有球形峰的微凸体。在2×10-5 Pa的高真空（HV）和大气压下的干燥和潮湿氮气中，使用原子力显微镜（AFM）测量每个粗糙体上的拉脱力和摩擦力。粗糙峰的曲率半径范围为70至610 nm。AFM悬臂的探针有一个扁平的正方形针尖，面积约为1×1 µm2。结果表明，拉脱力大致成正比的曲率半径的凹凸峰在每一个气氛。摩擦力与拉脱力成正比。湿氮气中的摩擦力对拉脱力的梯度略高于HV中的摩擦力，这表明毛细管的粘性阻力是摩擦力的一部分。HV中的摩擦力随着较低的滑动速度而增加，而不加热基底，这表明毛细管也具有防止直接固体接触的润滑作用。
Asperities having spherical peaks were fabricated on a silicon substrate using a focused ion beam. Pull-off and friction forces were measured on each asperity using atomic force microscopy (AFM) in a high vacuum (HV) of 2×10-5 Pa and in both dry and humid nitrogen at atmospheric pressure. The radius of curvature of the asperity peaks ranged from 70 to 610 nm. The probe of the AFM cantilever had a flat square tip, approximately 1×1 µm2 in area. The results showed that the pull-off force was roughly proportional to the radius of curvature of the asperity peaks in each atmosphere. The friction force was proportional to the pull-off force. The gradient of the friction force against the pull-off force was slightly higher in the humid nitrogen than in the HV, which suggests the viscous resistance of the capillary is part of the friction force. The friction force in HV increased with lower sliding velocities without heating the substrate, which suggests the capillary also has a lubricating effect that prevents direct solid contact.