Patent ID: 7287834

Claim:
A micro-electromechanical ink ejection device for a printer, the device comprising: a wafer substrate defining an ink inlet channel and incorporating drive circuitry; a nozzle chamber structure positioned on the wafer substrate and including a wall that defines a slot extending away from the substrate and a roof that defines a part-circumferential opening into the slot, the nozzle chamber structure defining a nozzle chamber in fluid communication with the ink inlet channel and an ink ejection port through which ink in the nozzle chamber can be ejected; an ink ejection paddle positioned in the nozzle chamber and displaceable towards and away from the ink ejection port to eject ink from the ink ejection port; a support extending from the wafer substrate outside the nozzle chamber; and an elongate actuator extending between the support and the paddle, a heater disposed at the support end of the actuator being connected to the drive circuitry to cause displacement of the paddle end of the actuator on receipt of a signal from the drive circuitry, the actuator being shaped to correspond with the slot and the part circumferential opening.