Testing and Simulation of Multilayer Polyvinylidene Fluoride-Based Piezoelectric Energy Harvester Devices

Power supply challenges for implantable medical devices, including pacemakers and health sensors, require device miniaturization for safe and minimally invasive implantation, as well as advancements in energy supply and storage technologies, such as high-density batteries and wireless power transmission. Traditional piezoelectric energy harvesters (EH) often exhibit high electrical impedances, which can restrict their use in energy harvesting systems. To address this limitation, a polymer-based multilayer flexible energy harvesting device composed of alternating dielectric and piezoelectric β-phase polyvinylidene fluoride (PVDF) layers is introduced. A theoretical mechanical model based on large-displacement beam theory is developed to quantify the stress experienced by the piezoelectric layer, and parametric simulations of the generated energy are conducted. Experimental results are compared with simulation outcomes. Furthermore, using real human heart kinematics obtained from epicardium surface measurements, the voltage and energy obtainable from the proposed devices are evaluated. The multilayer PVDF device demonstrates increased maximum output voltage and capacitance, along with reduced impedance compared to the single-layer configuration. The proposed EH multilayer PVDF-based provides significant advantages due to its simple and expandable architecture, indicating strong potential for supplying energy to small-scale devices for biomedical applications.