Performance Testing of a Piezoelectric Device for Extracting Energy from Vibrations

Energy harvesting from ambient sources is an interesting opportunity for wireless and self-powered electronics, increasing research efforts toward the development of new devices. Among all energy sources, vibrations seem particularly convenient for this kind of application. Piezoelectric resonant systems, though offering configurations well suited to recover energy from vibrations, suffer from narrow operational bands, and for this reason new solution to enhance performances at off-design excitation conditions is sought. In this paper a piezoelectric resonant energy harvester is developed, focusing the attention on both ceramics production method and support material choice in order to maximize the oscillation amplitudes, and consequently the energy output. The device produced at ISTEC laboratories is then compared with a commercial product under harmonic excitations. Results relative to power output show that the in-house assembled device has better performance than the commercial one in the considered tested conditions, both in absolute terms and with respect to the active piezoelectric volume of the two devices.