“…Nevertheless, the production of a hybrid composite part, consisting of a fragile metal insert and an ultra-thin-walled polymer cover, is still a challenge, especially given the small dimensions and tolerances of heart valve components. This requires full knowledge of the rheological properties of the polymer (TPU—Thermoplastic Polyurethane) [ 18 , 19 , 20 , 21 , 22 ], simulation methods exceeding the current state-of-the-art practices, precise positioning of the metal frame, and an adapted micro-injection molding cycle to avoid any collapsing of the frame due to the high pressure of the melt during filling in of the cavity [ 9 , 10 , 23 , 24 , 25 , 26 , 27 ]. Additionally, some aspects of heart-valve sealing to prevent wear of the TPU leaflet can be challenging.…”