Integrated Power Harvesting System Including a MEMS Generator and a Power Management Circuit

This paper presents a novel ambient energy scavenging system for powering wireless sensor nodes. It uses a MEMS generator and an ASIC power management circuit. The system is realised as a system on a package (SoP) with all components fabricated entirely using the microfabrication techniques. The electromechanical transduction is performed using the piezoelectric effect of aluminium nitride thin films. The reported experimental results prove the possibility of exploiting very low amplitude signals delivered by the generator for charging a storage capacitor. It is also shown that the proposed system of 5 mm³ can endlessly power a simple wireless sensor node; while a lithium-polymer thin film battery of the same volume can do so only for less than two months.