Integration of piezoelectric energy scavengers with FBAR resonators for the miniaturization of autonomous wireless sensors nodes

In this paper, the transduction part of a vibration-driven piezoelectric energy harvester has been designed, fabricated and characterized. The fabrication technology used allows the monolithic integration of Film Bulk Acoustic Resonators (FBARs) in the same wafer. This piezoelectric-based system together with an integrated circuitry can contain all the elements of a node that can belong to a wireless sensor network (WSN). A scavenged power of around 0.2 μW, i.e. an power density of around nd 0.13 mW/cm³, can be extracted at a resonance frequency of 515 Hz and an input acceleration of 0.64 m/s².