Multimodal analysis of generic cantilever-based piezoelectric nanogenerators with offset-proof mass

The present work investigates analytically and experimentally the multimodal performance analysis of piezoelectric (PZT-5A) based generic nanogenerators. The present nanogenerators consider both uni-morph and bimorph with offset-proof mass subjected to sinusoidal base excitation. The finite element-based multi-mode electromechanical coupled dynamics governing equations are derived to formulate the analytical expressions of uni-morph, and bimorph nano-harvesters for frequency responses function of output voltage, current, and power, respectively. The impact of base excitation, load resistance, thickness, length, and mass of offset-proof mass on the output voltage and harvested energy is investigated by considering multi-mode vibration bodies. PZT-5A is evenly distributed over the substructure for the single voltage output. Interestingly, we noticed that a uni-morph cantilever with offset-proof mass is the best among all the investigated configurations, showing the maximum power at different load conditions. Analytical solutions are in good agreement with nearly no error for the first few vibration modes as compared to what was obtained using numerical simulation. The experimental realization for a single mode of vibration has been explored, and results showed that the fundamental mode swings very similar behaviors in voltage and power output, mostly in pre-and post-resonance conditions as compared to analytical results, and the difference between these two results is about nearly 5%. Thus, the present work depicts an effectual correlation between analytical development, numerical results using COMSOL 2D, and experimental realization for analyzing energy harvesting devices. These results may be helpful for the experimentalists to design efficient nanogenerators.