A novel MEMS-based piezoelectric multi-modal vibration energy harvester concept to power autonomous remote sensing nodes for Internet of Things (IoT) applications

The Internet of Things (IoT) urges for development and pervasive deployment of energy-autonomous integrated remote sensing nodes. Microsystems-based (i.e. MEMS) Energy Harvesting (EH) seems to be a key-enabling technology to face such a challenge, and environmental vibrations are a source of energy commonly available in domestic, industrial and public contexts. A major limitation of standard vibration Energy Harvesters (EHs) is the power conversion performance typically pronounced just around the fundamental mechanical resonant frequency (narrowband device). In this work, we introduce a resonator design concept named Four-Leaf Clover (FLC). Having several mechanical Degrees Of Freedom (DOFs), the FLC EH-MEMS exhibits several resonant modes in the frequency range from around 200 Hz up to several kHz. Thereafter, it IS capable to convert mechanical into electric energy efficiently in a wide frequency range of vibrations (wideband device). The FLC EH-MEMS design concept discussion is corroborated by simulations and experimental measurements that verify its performance and, in turn, that provide support to the contribution it can bring to self-powered integrated sensing nodes in the IoT scenario.