Boosting the performance of energy harvesters subject to white Gaussian vibrations through impedance matching solutions

We discuss models of piezoelectric energy harvesters for scavenging energy from random mechanical vibrations, represented by a white Gaussian noise source. We show that circuit theory can be applied to design a matching network, to be interposed between the piezoelectric transducer and the load, able to increase the power transferred to the latter. The second order matching network is compared with a previously proposed solution, based on power factor correction, implemented through a single reactive element. We show that the new architecture boosts the harvested power with respect to the simple, unmatched resistive load, by a factor larger than 9, and with respect to the power factor correction solution by more than 17%.