In recent years, electroactive materials have attracted interest due to its applications in energy harvesting owing to piezoelectric nature. The energy harvesting with these PVDF piezoelectric polymers have great potential to remote applications such as in vivo sensors, embedded micro-electro-mechanical systems devices, and distributed network instruments. Using polymers for energy harvesting is a growing field, which has great potential from energy density viewpoint. The output power is inversely proportional to the harvester's frequency bandwidth. Consequently, it is much harder to efficiently harvest power from low-frequency sources with a large frequency band response and with a very small system size than from a stabilized high-frequency vibration source. This paper presents a mechanical prototype that is able to predict mechanical frequency excitation so as to increase power harvesting capabilities of piezoelectric polymers. An equivalent structure scheme has been developed using current and electrical schemes models; such a process rendered it possible to increase the converted power by 83% with a low-frequency mechanical excitation. This study contributes to provide a framework to develop an innovative energy-harvesting technology that collects vibrations from the environment and converts them into electricity to power a variety of sensors. (C) 2018 Elsevier Ltd. All rights reserved.