Patent ID: 7175260

Claim:
An inkjet printhead chip that comprises a wafer substrate, drive circuitry positioned on the wafer substrate, and a plurality of nozzle arrangements positioned on the wafer substrate, each nozzle arrangement comprising nozzle chamber walls and a roof wall positioned on the wafer substrate to define a nozzle chamber and an ink ejection port in the roof wall, a micro-electromechanical actuator that is connected to the drive circuitry, the actuator including a movable member that is displaceable on receipt of a signal from the drive circuitry, the movable member defining a displacement surface that acts on ink in the nozzle chamber to eject the ink from the ink ejection port, wherein the movable member of each actuator defines at least part of the nozzle chamber walls and roof wall so that movement of the movable member serves to reduce a volume of the nozzle chamber to eject the ink from the ink ejection port.