Patent ID: 8641388

Claim:
A household electric appliance having a pump equipped with a pumping chamber comprising a mobile wall formed by a metal membrane of electrically conductive material having an inner surface oriented to the inside of the pumping chamber and covered with at least one layer of electrically insulating material and the metal membrane also having an outer surface in contact with a piezoelectric actuator provided for displacing said metal membrane and forcing liquid from the pumping chamber by altering the volume of the pumping chamber under the action of said piezoelectric actuator, wherein said piezoelectric actuator is powered by voltage from a domestic mains, without interposition of an isolation transformer, and further wherein said inner surface of the metal membrane is covered with the at least one first electrically insulating layer possessing flame retardant properties and two electrically insulating supplementary layers each having a thickness less than the thickness of the at least one first electrically insulating layer.