Zeng Xingzhong, Peng Yitian, Lang Haojie, Cao Xing'an
College of Mechanical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
Nanotechnology. 2018 Feb 23;29(8):085706. doi: 10.1088/1361-6528/aaa2e5.
The nanotribological characteristics of silver nanowires (Ag NWs) are of great importance for the reliability of their applications in flexible nanodevices involving mechanical interactions. The frictional behaviors of Ag NWs on graphite substrate were directly investigated by atomic force microscopy (AFM) nanomanipulation. The relatively short NWs demonstrate three forms of motion-rotation, translation and a combination of the two-whose frictional behaviors behave like rigid rods. The relatively long Ag NW shows characteristics of a flexible beam, whose friction increases with an increase in the bending angle of the NW. The friction between the NW and substrate increases linearly with an increase in the length of the NW. The long Ag NW displays extraordinary flexibility that can be folded to different shapes, and the friction of the folded NW becomes smaller due to the decreased bending deformation. The critical aspect ratio of the Ag NW on graphite substrate for two different frictional behaviors between the relatively long and short NWs is found to be 12-15. These findings can deepen the understanding of the frictional characteristics of Ag NWs and contribute to their quantitative interface design.
银纳米线（Ag NWs）的纳米摩擦学特性对于其在涉及机械相互作用的柔性纳米器件中的应用可靠性至关重要。通过原子力显微镜（AFM）纳米操纵直接研究了Ag NWs在石墨基底上的摩擦行为。相对较短的纳米线表现出三种运动形式——旋转、平移以及两者的组合——其摩擦行为类似于刚性杆。相对较长的Ag NW表现出柔性梁的特性，其摩擦力随着纳米线弯曲角度的增加而增大。纳米线与基底之间的摩擦力随着纳米线长度的增加而线性增大。长Ag NW展现出非凡的柔韧性，能够折叠成不同形状，并且由于弯曲变形减小，折叠后纳米线的摩擦力变小。发现对于相对长、短纳米线之间两种不同摩擦行为而言，Ag NW在石墨基底上的临界长径比为12 - 15。这些发现能够加深对Ag NWs摩擦特性的理解，并有助于其定量界面设计。
