An ink ejection nozzle arrangement is provided for an inkjet printer. The arrangement includes a wafer assembly defining an ink supply channel. A nozzle chamber structure is mounted to the wafer assembly, and defines a nozzle chamber for receiving ink from the ink supply channel and an ink ejection port through which ink in the nozzle chamber can be ejected. An anchor extends from the wafer assembly in a location external to the nozzle chamber. An elongate thermal actuator mechanism extends from the anchor and into the nozzle chamber. The thermal actuator mechanism includes an elongate arm which terminates in a free end within the nozzle chamber and a pair of layers of conductive material located on either side of the elongate arm. One of the layers is connected to a current supply so that the free end of the arm can be moved to eject ink in the nozzle chamber through the ink ejection port as a result of differential thermal expansion.