Improving piezoelectric energy harvesting performance through mechanical stiffness matching

The mechanical energy transfer between the source structure and active material in piezoelectric energy harvesters is investigated here. First, an analytical prediction to improve mechanical energy transfer into the piezoelectric material is proposed and validated by tailoring the stiffness of the beam to off-the-shelf piezocomposites through numerical models and experiments. An experimental study is then presented whereby the mechanical properties of freeze cast piezocomposites are controlled by adjusting the volume fraction of piezoceramic and epoxy filler phases. This offers a new approach for tailoring the mechanical properties of piezocomposites to maximize mechanical energy transfer into the material via stiffness matching.