Analytical Modeling and Experimental Validation of an Optimized Auxetic Composite Plate for Enhanced Piezoelectric Energy Harvesting

Piezoelectric energy harvesters show promise for powering small electronics by scavenging ambient vibration energy. However, increasing output voltage remains challenging due to the limitations of traditional harvester designs. This study demonstrates a novel approach using optimized auxetic plate vibrations to boost piezoelectric energy conversion efficiency. An analytical model is derived for a clamped-free plate energy harvester incorporating auxetic effects through both <FOR VERIFICATION>d31 and <FOR VERIFICATION>d32 piezoelectric coupling modes. Finite element analysis optimizes the auxetic plate geometry for maximum voltage generation. Experimental validation is conducted on 3D-printed harvesters with simple, optimized auxetic, and single unit cell plate configurations. Results show the optimized auxetic plate increases voltage by over 30% compared to a conventional design under base excitation. The analytical model agrees well with simulations and empirical data. Parametric sweeps reveal peak performance corresponds to a hexagonal auxetic unit cell length of 8<FOR VERIFICATION>mm. This work establishes auxetic plate vibration mechanics as an effective means to augment piezoelectric strain and enhance energy harvester output. The calibrated analytical-computational-experimental methodology provides insight for piezoelectric harvester design optimization through auxetic material integration. This auxetic-based approach offers a pathway to improve various energy transduction mechanisms for self-powered applications.