Improvements to ferroelectric durability

摘要

A piezoelectric actuator (21) for use in a fuel injection system of an internal combustion engine, the actuator comprising a stack (34) of ferroelectric layers (16); an encapsulation (36) for protecting the stack (34) from the ingress of liquid; and oxygenation means for providing oxygen to the ferroelectric layers (16), the means positioned between the encapsulation (36) and stack (34). The oxygenation means is preferably impregnated in a fabric (22) which forms a layer between the encapsulation (36) and the stack (34).