Performance testing of piezoelectric energy harvesting for extracting energy from vibration

Recovery energy from vibrations is a promising opportunity for different type of structures, like buildings, roads, machinery, vehicles, and so on. Vibrations affect the considered structures with different levels of intensity and, in this way, the energy source is available at several locations, for instance allowing for powering of wireless sensors, led lights and other low-consumption electrical loads, such as IoT components, without the need of cabling. Piezoelectric benders, i.e., cantilevers beams embedding piezoelectric materials, are compact and easy-to-install devices, and in fact they are widely studied [1]. The performance of the piezoelectric devices depends on the piezo material, layer configuration and geometry. In this work, several piezoelectric harvesters, produced at the ISTEC laboratories as well as available on-the-shelf, are tested using a test-rig where an aluminium plate is excited with a shaker. The cantilever piezoelectric devices are exposed to harmonic excitation and experimental results relative to the voltage and the power output are illustrated, including analysis of the linearity of the response with different level of excitation.