This paper presents both simulation and experimental results on the principal characteristics of vibration energy harvesting with electromagnetic and piezoelectric seismic transducers. The electromagnetic seismic transducer is formed by coil-magnet components connected via soft springs. The piezoelectric seismic transducer is made by a thin cantilever beam with piezoelectric patches bonded on the top and bottom sides and a block mass fixed at the free end. The two transducers are design and built in such a way as they have the same weights of the base and suspended masses and the same fundamental natural frequency. A unified lumped parameter model based on the frequency response functions of the electro-mechanical transduction coefficients and mechanical and electrical impedances is derived and validated experimentally. A formulation is thus introduced for the energy harvested with the two transducers. The spectra of the power harvested per unit base vibration of the two harvesters are simulated and validated experimentally.
