Abstract
It has been clarified that liquid lubricants confined in nanometer-sized gaps have different mechanical properties from those in bulk state, and it is necessary to consider these effects on lubrication design. In our previous studies, authors have established high-precision nano-rheology measurement method (fiber wobbling method), clarified that unique viscoelasticity of lubricants in nano gaps. In the conventional measurement, however, the effective contact area between the probe and the lubricant is several square microns, whereas the sliding distance is about several tens of nm. It means that the sample liquid in nano gaps is sheared without being replaced. On the other hand, in actual lubrication between mechanical elements, it is supposed that the sliding distance is sufficiently large as compared with the contact area. In order to measure the viscoelasticity of the lubricant under such conditions, the purpose of this research is to realize a sliding distance of micrometer order while maintaining the nano gaps in viscoelastic measurements using the fiber wobbling method.
