an inkjet printhead integrated circuit has a substrate . a drive circuitry layer is positioned on the substrate . the substrate and the drive circuitry layer define a plurality of ink inlet channels . nozzle chamber walls and roofs spanning the nozzle chamber walls are positioned on the substrate to define nozzle chambers in fluid communication with respective ink inlet channels . the roofs define respective ink ejection ports . ink ejection members are positioned in respective nozzle chambers and are displaceable with respect to the roofs to eject ink from the ink ejection ports . thermal actuators are outside of and associated with respective nozzle chambers and are connected to the drive circuitry layer to move with respect to the substrate on receipt of electrical signals from the drive circuitry layer . work transmitting structures define at least one of the walls of respective nozzle chambers and are configured to transmit work from the actuators to the ink ejection members . pairs of work transmitting structures and associated ink ejection members each have a common layer of fabrication material .