Piezoelectric Polymer Characterization Setup for Active Energy Harvesting

Piezoelectric polymers, such as poly(vinylidene fluoride) (PVDF), offer a sustainable alternative to traditional ceramic-based energy harvesters, addressing concerns regarding environmental impact and resource scarcity. The energy harvesting ability of these PVDFs under various mechanical constraints has been widely investigated. To determine the power output of the material, most of the studies usually use the same electrical setup: the piezoelectric material is in series with a load resistor and the voltage is measured at the resistor's terminals. This usual "passive" method of measurement can underestimate the optimal value of energy harvesting ability. To accurately assess the energy harvesting potential of PVDF, a novel "active" measurement method is proposed. This method involves the simultaneous application of both mechanical and electrical stimuli to the PVDF film, enabling precise control and optimization of the energy harvesting process. To validate this approach, the structural and electrical properties of the stretched PVDF were initially characterized to produce a datasheet. Subsequently, the energy harvesting performance was investigated using both "passive" and "active" methods. The results demonstrated a significant enhancement in power output, with the "active" method yielding up to 3.2 times higher values compared with the "passive" method. This finding highlights the importance of employing advanced measurement techniques to accurately characterize the energy harvesting capabilities of piezoelectric materials.