Dynamic Analysis behaviour of an electro mechanical energy harvester beam based on piezoelectricity

Dynamics of an electromechanical energy harvesting cantilever beam deposited by two piezoelectric layers throughout the entire length have been studied. Two different output circuit configurations including parallel and series connections have been investigated. The free and forced vibration problem is studied by discretizing the motion equation and numerically solving the resultant along with the governing electrical equation. The energy conservation law for the proposed electromechanical energy harvesting device has been examined and accordingly verified. The behavior of the energy harvester subjected to various external load resistances was studied and it was concluded that in the absence of mechanical viscous damping, the system exhibited damped response which was attributed to the energy consumption throughout the output circuit. It was proved that as the external load resistance increases the attenuation rate of the response amplitude and accordingly the harvested voltage does also increase. The amount of harvested power for both parallel and series output circuit configurations were examined and it was concluded that in series configuration the harvested voltage in compare with that of the parallel connection is considerably higher; however the harvested current was lower than that of the parallel connection.