Study on the performance of tailored spring elements for piezoelectric MEMS energy harvesters

Energy harvesting has recently attracted much attention of the research community as a key enabling technology in applications such as autonomous Wireless Sensors Network (WSN), Internet of Things (IoT), e-health and more in general all the applicative scenarios requiring an autonomous low power distributed system. Among the various energy harvesting techniques, vibrational piezoelectric energy harvesters have several advantages compare to other solutions (e.g. high output density power, high output voltage). One of the main constraints in the exploitation of such a technology is the limited bandwidth of the devices, intrinsic to the mechanical resonator typically used. In this contribution, different resonators based on a cantilever-like structure are studied both by FEM simulation and by measurements of physical samples. The goal of this preliminary study is to verify the effectiveness of those whip designs for energy harvesting purposes.