Patent ID: 7524034

Claim:
An ink jet printhead comprising: a substrate including a plurality of nozzles adapted for supply with an ejectable liquid; a nozzle plate having a plurality of ink ejection openings defined therein, each opening corresponding to a respective nozzle, each nozzle having a respective nozzle chamber; a heater corresponding to each of the nozzles respectively, the heater having at least one heater element in the form of a suspended beam having an upper and a lower face in thermal contact with a bubble forming liquid, said beam being parallel with a plane of said nozzle plate; and, drive circuits corresponding to each of the nozzles respectively for controlling the operation of the heater; such that, heating the heater element to a temperature above the boiling point of the bubble forming liquid forms a gas bubble that causes the ejection of a drop of the ejectable liquid through the ink ejection opening, wherein each heater element includes solid material having a thickness of at least 0.25 microns and is configured for a mass of less than 10 nanograms of the solid material of that heater element to be heated to a temperature above said boiling point.