Patent ID: 7131717

Claim:
An inkjet printhead integrated circuit comprising: a substrate that defines a plurality of ink supply channels; a drive circuitry layer positioned on the substrate; and a plurality of nozzle arrangements positioned on the substrate electrically connected to the drive circuitry layer, each nozzle arrangement comprising: a chamber defined by the substrate; a roof positioned over the nozzle chamber, the roof having a rim defining an ink ejection port, the rim being supported above the respective ink supply channel with support arms that extend from the rim to the drive circuitry layer; and at least one thermal actuator positioned in the roof, at least one portion of the thermal actuator being made of a material which expands when heated, the at least one portion being interposed between two of the support arms and the thermal actuator being arranged to receive an electrical current from the drive circuitry layer to thereby heat the at least one portion, wherein, upon receipt of the current the thermal actuator is configured to be displaceable towards the substrate so as to reduce a volume of the chamber, so that ink is ejected from the ink ejection port.