Material Damping Analysis of Triangular Cantilever Beam for Electromagnetic Vibration Energy Harvesting Applications

Vibration energy harvesting (VEH) have emerged as one of the most promising sources of sustainable energy to power low-powered electronics and structural health monitoring. However, research that involves powering larger devices have also been explored. Among the different approaches to convert mechanical vibrations into electricity, the two most common applied methods are piezoelectric transducers and electromagnetic induction. While piezoelectric VEH generally dominates in the micro-volume scale, electromagnetic VEH tends to perform better at larger volumes. Triangular cantilever beam are often desired in piezoelectric vibration energy harvesting applications as they result in a better performance due to a higher and more uniform stress. However, the application of this cantilever geometry has not yet been explored for other transduction methods. In this study, the application of a triangular cantilever beam for a cantilevered electromagnetic vibration energy harvester was examined by analyzing its material damping and comparing it to a regular rectangular beam. The material damping of the harvester was predicted through finite element analysis using the critically damped stress method. Under the same beam volume or beam length, the triangular cantilever beam exhibited an approximately 7.1% lower material damping when compared to a rectangular cantilever beam. Further analysis shows that the triangular beam can also deliver a 21.7% higher power output than the rectangular beam.