Enhanced vibrational energy harvester based on velocity amplification

We propose a vibrational energy harvester with enhanced power capability based on velocity amplification through sequential pair-wise collisions between multiple masses in series. Under vibrational stimuli, sequential impacts of mass pairs can produce a velocity amplification of more than a factor of three on the smallest mass of the train. Thus, by rendering this element magnetically active, an amplified current is induced in a coil. Experimental tests performed on a two- and three?mass prototype demonstrate more than a factor of 28x of power gain compared to a single-mass resonant configuration under wideband random vibrations.