Patent ID: 7325901

Claim:
An ink jet nozzle arrangement for ejecting ink, the ink jet nozzle arrangement comprising: a substrate that defines an ink inlet; integrated circuitry positioned on the substrate; a nozzle structure positioned on the substrate and defining a nozzle chamber in fluid communication with the ink inlet and an ink ejection port in fluid communication with the nozzle chamber from which ink can be ejected; and an elongate actuator having a fixed end fast with respect to the substrate and a free end extending into the nozzle chamber, the actuator comprising a pair of mechanically coupled and electrically isolated arms extending along the substrate with one of the arms being interposed between the other arm and the substrate, the interposed arm being electrically coupled to the integrated circuitry; wherein the actuator is configured so that when the interposed arm receives an electrical signal from the integrated circuitry, the actuator experiences differential thermal expansion and bends to induce movement of its free end and thereby eject ink in the nozzle chamber from the ink ejection port.