Electromechanical characterization of didactical piezoelectric sensors based on crystalline grade PET

A mechanical shock or impact sensor system for teaching purposes was developed and characterized. The device consists of Mylar layers (3×3 to 21×21 cm2) confined by aluminum sheets. The metallic surfaces are wired in order to send their signals to a digital oscilloscope. The instrument receives voltage variations after the surface of the transducer is stroked by a plastic projectile (capsule mass: 50 g) released in free fall (heights: 0.15 - 3 m). The respective piezoelectric constant was determined to be d = 42.02±10−12 m/V. This proposed experiment can be attractive for a basic instrumentation course which combines both theoretical and experimental concepts of mechanics and materials sciences.