Improved piezoceramic energy harvesting circuit for self-powered wireless sensor nodes

In recent years the demand for completely autonomous systems has increased considerably in many remote sensing applications with substantial business potential. Ensuing research efforts in this field have acknowledged energy harvesting as an effective technology to overcome the limited lifetime of battery-powered systems. This paper presents a newly designed vibrational energy harvester, capable of powering indefinitely any low power wireless sensing node with the mechanical energy freely available in its own operating environment, collected by means of a custom built piezoceramic transducer. The circuit architecture outperforms similar solutions available in literature in terms of standby power consumption, cold-starting ability and in-the-field customization, to accommodate a wide range of operating conditions and piezoelectric transducers. The soundness of the design has been experimentally assessed on the harvester prototype with a thorough analysis of the efficiency of all the circuits involved in the power processing chain.