The goal of this project is to continue the development of an optofluidic technique to characterize the rheology of spatially-confined thermoplastics. It is based on sensing changes in optical properties of a porous thin film due to the capillary filling of a liquid into the pores. The rheological information can be obtained as a function of temperature from the time evolution of the optical thickness of the film. The importance of this project resides in the simplicity of the experimental set-up. Moreover it enables one to estimate the viscosity in conditions of nano-confinement, which cannot be done using standard rheometers.