On the application of circuit theory and nonlinear dynamics to the design of highly efficient energy harvesting systems

Ambient dispersed mechanical vibrations are a viable energy source, that can be converted into usable electric power. Ambient vibrations are random process, that can be modeled by superposition of periodic signals. When most of the energy is concentrated in a narrow frequency band, a single periodic function may be a reasonable approximation. This work shows that circuit theory, complemented with nonlinear dynamics methods, are instrumental in designing efficient energy harvesters for ambient mechanical vibrations. It is also shown that the average extracted power can be maximized by a proper load matching, and that the introduction of nonlinearities results in a larger frequency bandwidth, increasing the efficiency of the harvester at frequencies close to the resonance. Even for the nonlinear harvester, the matched load boosts the performance by a large amount.