Modelling of piezoelectric sandwich energy harvester with auxetic cores

This paper presents a comprehensive study on the modelling and optimisation of a piezoelectric sandwich energy harvester featuring auxetic cores compared to isotropic cores, aimed at enhancing vibrational energy harvesting efficiency. The proposed auxetic piezoelectric energy harvester with a tapered thickness is engineered to achieve a more uniform stress distribution, leading to significant improvements in power output and energy density compared to conventional uniform-thickness designs. Through finite element analysis (FEA) and experimental validation, the optimised TAEH demonstrates enhanced electromechanical performance. Additionally, a numerical model is developed to simulate the dynamic behaviour of the energy harvester with auxetic substrates. Simulations reveal that the auxetic core induces biaxial strain in the piezoelectric material, generating higher electrical output without increasing mechanical stress. The model is refined through iterative simulations to accurately predict the harvester’s structural and electrical performance, showcasing the potential of auxetic designs to advance the field of sustainable vibrational energy harvesting in mechanical systems.