Patent ID: 7441876

Claim:
An inkjet printhead comprising a plurality of micro-electromechanical nozzle arrangements having an areal density of at least 40,000 nozzles per square centimetre on a printing surface of the printhead, wherein each nozzle arrangement comprises a substrate; side walls extending from the substrate and supporting a nozzle plate to define a fluid chamber, the substrate defining a fluid inlet to said chamber, and the nozzle plate defining a nozzle from the chamber terminating in the printing surface; and at least one heater element suspended in the fluid chamber operatively containing a printing fluid supplied via the inlet, wherein activation of the heater element forms a vapour bubble in the fluid leading to a pressure increase in the chamber thereby ejecting the fluid via the nozzle, said heater element configured so that a point of collapse of the bubble is spaced from the heater element.