PZT ceramic particles/polyurethane composites formalism for mechanical energy harvestingAbdelkader Rjafallah, Abdelowahed Hajjaji, Fouad Belhora, Abdessamad El Ballouti, Samira Touhtouh, Daniel Guyomar and Yahia BoughalebEur. Phys. J. Appl. Phys., 89 3 (2020) 30901DOI: https://doi.org/10.1051/epjap/2020190102