Experimental analysis of viscous and material damping in microstructures through the interferometric microscopy technique with climatic chamber

This study describes an experimental analysis of energy dissipation due to damping sources in microstructures and micro electro-mechanical systems (MEMS) components using interferometric microscopy techniques. Viscous damping caused by the surrounding air (squeeze film damping) and material damping are measured using variable geometrical parameters of samples and under different environmental conditions. The equipment included a climatic chamber designed (built ad hoc) which was used to modify the surrounding air pressure. Results show the relationship between damping coefficients and sample geometry caused by variation in air flow resistance and the relationship between quality factor and air pressure. The experimental results will provide a useful data source for validating analytic models and calibrating simulations. A thorough discussion about interferometry applied to experimental mechanics of MEMS will also contribute to the reduction of the knowledge gap between specialists in optical methods and microsystem designers.