Patent ID: 7438391

Claim:
A micro-electromechanical nozzle arrangement for an inkjet printhead, said arrangement comprising: a substrate defining an inverted pyramidal ink chamber with an ink supply channel leading through the substrate, said substrate having a layer of drive circuitry; a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber in addition to ink flow guide rails to minimize wicking along the nozzle rim according to surface tension effects of ink in the chamber; and a plurality of actuators displaceable with respect to, and radially spaced about, the nozzle rim, and in between, the guide rails, each actuator having a serpentine heater element configured to thermally expand upon receiving current from the drive circuitry thereby moving said actuators into the chamber operatively increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle.