Tuning the nanotribological behaviors of single silver nanowire through various manipulations

Abstract

Nanotribological characteristics of silver nanowires (Ag NWs) are of great importance for the reliability of their applications where involving mechanical interactions. The frictional behaviors of the Ag NWs with different lengths on SiO2/Si substrate have been investigated directly by atomic force microscopy (AFM) nanomanipulation. The relatively short and long Ag NWs behave like the rigid rods and flexible beams, respectively, and the critical aspect ratio of NWs for the two cases is found to be about 20. The relatively short NWs demonstrates three forms of motion with different frictional behaviors. The friction of the relatively long NWs increases with the bend of the NWs. The long Ag NWs display extraordinary flexibility that can be folded to different shapes, and the folded NWs show a similar frictional behavior with the rigid rods. Different simplified mechanical models are established to match the frictional behaviors of the corresponding Ag NWs. The adhesion between the Ag NWs and substrate is calculated by an indirect method based on the van der Waals force equation to assess their adhesive attraction. These findings may provide insight into the frictional characteristics of Ag NWs and contribute to the quantitative interface design and control for their applications.