Multi-electrode piezoelectric energy harvesters

In this work, a model for a doubly-clamped piezoelectric energy harvester having multiple electrodes and a central proof mass is presented. The model is based on Euler-Bernoulli beam theory, accounts for the distributed effects of the proof mass and for the exact location of the strain nodes, and is therefore of high accuracy in predicting voltage and charge distributions. We use such model in the context of the electrode optimal placement for maximum power output. Single-mode terminal voltage outputs for various connection configurations between the electrodes are obtained under given resistive loads. The theoretical solutions are found to closely agree with Finite Element Method (FEM) simulations obtained from Coventor MEMS+ and Cadence Virtuoso.