FEMTO-ST Institute (UMR6174, rated A+) is one of the biggest and most competitive French laboratories in engineering sciences (about 700 persons). Technological platform MIMENTO of FEMTO-ST, dedicated to micro-fabrication of acoustic and optic components with long-years expertise on electro-active and piezoelectric materials such as alkaline niobates and manufacturing including thin film growth and integration of single crystal films, is one of the biggest clean rooms in France (network RTB). In FIESTA, FEMTO-ST is in charge of chemical/phase transition engineering, elaboration of single-crystal & ceramic KTN films based on piezoelectric KTN crystals or powder (possibly with LGEF for the latter aspect), characterization of structural and physical properties (electrical, piezoelectric and acoustical) of thin films, and microfabrication and characterization of acoustic devices.