Feasibility study of using amplified piezo-stack actuators for the actuation of direct drive servovalvesPaolo Tamburrano, Pietro De Palma, Andrew R. Plummer, Elia Distaso and Riccardo AmiranteE3S Web Conf., 197 (2020) 07004DOI: https://doi.org/10.1051/e3sconf/202019707004