Dynamics of a vibrational energy harvester with a bistable beam: voltage response identification by multiscale entropy and “0-1” test

The use of bistable laminates is a potential approach to realize broadband piezoelectric-based energy harvesting by introducing elastic non-linearities to the system. In this paper the dynamic response of a piezoelectric material attached to a bistable laminate beam is examined based on the experimental measurement of the generated voltage-time series. The system was subjected to harmonic excitations and exhibited single-well and snap-through vibrations of both periodic and chaotic character. The ability to identify the vibration modes of the energy harvester is important since different levels of power are expected in each dynamic mode. We identify the dynamics of the selected system response using return maps, multiscale entropy, and “0-1” test. The potential of the approaches to identify periodic and chaotic modes and snap-through events in the non-linear bistable harvester is described.