Inkjet nozzle that incorporates volume-reduction actuation

1. An inkjet nozzle comprising:

a substrate defining an ink chamber; and

a cover mounted to the substrate and covering the ink chamber; the cover comprising a rim that defines an ink ejection port through which ink can be ejected, a plurality of fixed support arms supporting the rim, and a plurality of movable actuator arms each located between an adjacent pair of fixed support arms and which can move into the chamber to eject ink from the ink ejection port; the actuator arms extending radially outwardly from the rim and collectively having rotational symmetry.

2. An inkjet nozzle as claimed in claim 1 , wherein the actuator arms have rotational symmetry of an order of six.

3. An inkjet nozzle as claimed in claim 1 , wherein the substrate includes a wafer, and a CMOS drive layer deposited upon the wafer which is configured to drive the movement of the actuator arms.

4. An inkjet nozzle as claimed in claim 1 , wherein the ink chamber is tapered inwardly away from the cover.

5. An inkjet nozzle as claimed in claim 4 , wherein the substrate defines an ink inlet which is located at a tip of the tapered chamber, the inlet being aligned with the ink ejection port.

6. An inkjet nozzle as claimed in claim 1 , wherein each actuator arm includes a heater which can be activated to displace the arm.

7. An inkjet nozzle as claimed in claim 1 , wherein each actuator arm includes an enlarged free end located proximate the rim.

8. An inkjet nozzle as claimed in claim 7 , wherein each free end is tapered.