a nozzle assembly is provided for ejecting ink . the nozzle assembly includes a substrate incorporating drive circuitry . an actuator support extends from the substrate . an actuator arm extends from the actuator support and includes a heater which is coupled to the drive circuitry . a nozzle extends from the substrate at a spaced apart location from the actuator support and the heater . the nozzle defines an ink chamber in fluid communication with : an ink supply , an ink ejection port in fluid communication with the nozzle chamber , and a slot through which the actuator arm extends and terminates in a free end within the ink chamber . responsive to the heater receiving an electrical signal from the drive circuitry , the free end of the actuator arm is displaced in the ink chamber to eject ink contained therein through the ink ejection port .