Application of surface plasmon resonance to measurement of hydrostatic pressure in tribological lubricant layers

A new method for studying elastohydrodynamic lubrication (EHL) dimple is demonstrated. This technique uses the spectral characteristics of surface plasmon resonance (SPR) to perform imaging of the dimple. Due to SPR absorption shift for different refractive index values, the refractive index variation across the dimple can be investigated by the color variation in the reflecting dimple image. Several dimples produced at different impact force levels have been studied in our experiments and the refractive index changes associated with such experimental conditions have been successfully identified by the spectral SPR imaging. The internal pressure distribution within the dimple is discussed.