Sliding friction of elastomer with well-defined surface topography and in situ observation of its frictional interface

摘要

When two macroscopic bodies are brought into contact, multi-asperity contact is formed between the two bodies. Multi-asperity contact plays a key role in macroscopic sliding friction. However, a question as to how dynamics of individual contact spot is related to the macroscopic motion of the sliding sample is not fully understood. The understanding has been hampered by the following two reasons. Firstly, in many cases, frictional interfaces are not optically accessible. Secondly, due to random nature of surface topography of solids, analysis of solid contacts is complicated [1]. A model system which can avoid these two obstacles may extend understandings of macroscopic sliding friction. Here, we intend to develop such a model system, whose frictional interface has a simple structure and is optically accessible, by employing a friction system of elastomer with well-defined surface topography sliding over a prism. We characterized the sliding motion observed in this friction system under various conditions, and performed in situ observations of the frictional interface during sliding.