“…Among them, the devices based on the piezoelectric effect are attracting the interest of the scientific community, since they can be used not only for energy harvesting processes [ 9 , 10 , 11 ], but also in daily used devices, such as, for example, microphones and vibration sensors [ 12 ]. Direct and inverse piezoelectric effect are well-known phenomena since the end of the XIX century [ 13 , 14 ], which can be exploited in resonators [ 15 ], micropumps [ 16 ], or more complex systems like sonars [ 17 ], continuous pressure monitor devices, [ 18 ] and in the so-called piezoelectric surgery [ 19 ]. Alongside this, pushed by the dramatic increases of energy request, the use of piezoelectric materials, as devices for energy harvesting, appears to be a very appealing research field [ 20 , 21 , 22 , 23 ].…”