Astrophysical dust plays a major role in stellar formation and evolution, and in the chemical enrichment of the Galaxy. However, the processes which lead to its formation in the circumstellar environment of evolved stars, and describe its interactions with the Interstellar Medium, are largely unknown. Mid-IR observations, combined with radiative transfer modeling aimed to derive the dust physical parameters from its thermal emission, are our best tool to investigate the physics of dust in many astrophysical contexts.
