A Novel Full Stressed Energy Harvester with Varied Thickness

Abstract

This study developed a novel full stressed energy harvester composed of a cantilever with varied thickness in the length direction to harvest energy from ambient vibrations. This harvester owns a higher efficiency of energy harvesting when compared with the harvester of a uniform cross section, since the maximum bending stress is constant in each cross section. The current available models for cantilever harvesters are inapplicable to the new improved fully stressed harvester due to its unique shape. By employing Rayleigh-Ritz method, a corresponding governing equation is hence developed to model the full stressed harvester for estimating the efficiency. The influence of the geometry on the generated electric power is also discussed for the full stressed harvester. The results show that the full stressed harvester can double the electric power generated by the uniform harvester, and the full stressed harvester has a lower natural frequency.