With the decrease in energy consumption of electronic sensors, the concept of harvesting renewable energy in human surrounding becomes a must. In this context, piezoelectric generators seems promising since they can harvests mechanical vibrations and in general energy available in nature. The aim of this paper is to design a piezoelectric generators, optimized for different kind of sensors and electronic equipments, able to work under the sea or into rivers, which can work with natural water vibrations generated by solid-fluid objects interactions (Von-Karman Vortex) and then to test the effectiveness of the device developing an electronic board to analyze the behavior of the generator