Improved strain distribution of cantilever piezoelectric energy harvesting devices using H-shaped proof masses

This article proposes a cantilever piezoelectric energy harvester consisted of an ordinary rectangular beam and an H-shaped proof mass. The H-shaped proof mass comprises two detached metal blocks that can provide large rotary inertia. A uniform strain distribution along the composite cantilever could be obtained by selecting an appropriate mass ratio between the detached metal blocks and vibration mode. We also fabricated a prototype H-shaped energy harvesting device. The result of the experiment done on the device is identical with both the theoretical and finite element analyses.