Nanosensors for Pressure and Temperature Mapping in Confined Lubricant Films

Pressure and temperature are two relevant parameters in the elastohydrodynamic lubrication (EHL) regime. For instance, the pressure may reach values up to 1-2 GPa inducing an important elevation of the lubricant viscosity. In addition, the temperature can rise up to 100°C due to sliding conditions.A new in situ experimental technique allowing local and simultaneous measurement of pressure and temperature in lubricated contacts is under development. This technique is based on the sensitivity of some photoluminescent nanoparticles (NP) to temperature and pressure variations.In this paper, the calibration of different semiconductor-based NP dispersed in lubricant is detailed and their potential use as nanosensors is discussed. Their respective temperature and pressure sensitivities (variations of the fluorescence wavelength) were calibrated using a high pressure diamond cell in which temperature can be controlled precisely