Inkjet printhead with nozzle assemblies having fluidic seals

1. An inkjet printhead for a printer, the printhead having a plurality of micro-electromechanical nozzle assemblies, each nozzle assembly comprising:

a substrate defining an ink inlet channel;

an arm connected at a first end to a thermal actuator fast with said substrate via an anchor arrangement; and

a nozzle defining an ink aperture over the ink inlet channel, wherein

the nozzle has a nozzle rim connected to a second end of the arm opposite the first end and is displaceable towards the substrate by the actuator to eject ink from the aperture, and

the nozzle includes a skirt portion depending downwards from the nozzle rim and a wall portion extending upwards from the substrate, the wall portion having an inwardly directed lip that forms a fluidic seal with the skirt portion.

2. The printhead of claim 1 , wherein the actuator includes an active beam and a passive beam, and thermal expansion of the active beam produces a moment on the nozzle rim via the arm.

3. The printhead of claim 1 , wherein the substrate includes a dielectric layer in the form of a CVD oxide.

4. The printhead of claim 1 , further comprising a nozzle guard mounted on the substrate, the nozzle guard having a shield that defines a plurality of apertures.

5. The printhead of claim 3 , wherein a CMOS passivation layer is deposited on the dielectric layer, said CMOS layer facilitating electrical actuation of the actuator.

6. The printhead of claim 4 , wherein the nozzle guard is formed from a material having a coefficient of thermal expansion that substantially matches that of the nozzle assembly.

7. The printhead of claim 5 , wherein the anchor arrangement is mounted on conductive pads providing an electrical connection to the CMOS layer.