Piezoelectric actuator for a flow-around of a medium arrangement

Disclosed is a piezoelectric actuator module (03) for flow around by a medium assembly comprising an actuator base (05) and an actuator head (04) and at least one intervening enclosed piezoelectric actuator (16) comprising at least the piezoelectric actuator (20) surrounding protective layer system (17 ) of one or more functional layers, wherein the protective layer system (17) comprises at least: - a first layer consisting of a surrounding said at least one piezoelectric actuator (16) at its two ends to the actuator base (05) and the actuator head (04) high-pressure-tightly connected to metal sleeve (18, 24), and - a by the actuator base (05) and the actuator head (04) limited space between the metal sleeve (18, 24) and the at least one piezoelectric actuator (16) completely fills second layer consisting of an elastomer and / or an electrically nonconductive oil having.