Experimental Setup for Testing Low Energy Harvesting Devices Based on Lead-Free NBT-BT-PVDF Composite Flexible Films

The paper presents the realization of an experimental setup used for testing energy harvesting and storage devices based on the use of lead-free bismuth sodium titanate-barium titanate (NBT-BT) in combination with polyvinylidene fluoride (PVDF) polymer. PVDF is a polymer matrix in which piezoelectric phase is dispersed and enables formation of flexible films by hot pressing method. The paper presents an electromechanical model of a typical PVDF module, generates a simulation model, and presents simulation results. The experimental setup is based on a mechanical excitation for generating pulses of an force of different amplitude and duration, applied on the aforementioned energy harvesting NBT-BT-PVDF devices, likewise, on an electronic assembly for measuring the pulses of electrical quantities (current and voltage), that are generated at the output electrodes. The research in this paper is predominantly experimental and it shows the obtained oscilloscope recordings of the excitation force and output voltage of energy harvesting modules at different modes and conditions of mechanical excitation. After this, a comparison of the simulation and experimental results is made.