Highly-coupled PZT-based vibration energy harvester for broadband applications

International audienceThis paper reports on the design and experiment of a highly-coupled piezoelectric energy harvester. Such a device is necessary to benefit from non-linear electrical techniques to improve the frequency bandwidth. A previously developed 2-degree of freedom (2-DOF) analytical model is improved with the Rayleigh method and is used to understand electromechanical interactions and for a preliminary design. As a result, we built a PZT-5A cantilever embedding a long proof mass. The tests demonstrate a strong electromechanical coupling coefficient (k²=10.2% for the 1 st mode)