Gas pressurised encapsulation for an actuator

摘要

A piezo-electric actuator (1) for use in a diesel engine. The actuator (1) comprises a piezo-electric element (3) which is encapsulated such that a layer of gas at a pressure above atmospheric pressure surrounds the piezo-electric element. The presence of the gas within the encapsulation around the element (3) avoids the need to passivate electrodes exposed on the surface of the element.