Thermal bend actuator with conduction pad at bend region

1. A thermal bend actuator comprising:

a first active cantilever beam for connection to drive circuitry, said first beam comprising a bent planar beam element;

a second passive cantilever beam fused to the first beam, such that when a current is passed through the first beam, the first beam expands relative to the second beam resulting in bending of the actuator;

at least one conduction pad sandwiched between said first and second beams, said conduction pad being positioned at a bend region of said planar beam element so as to facilitate electrical conduction around said bend region; and

first and second adjacent electrode contacts positioned at one side of the actuator, wherein a first end of said beam element is connected to said first contact and a second end of said beam element is connected to said second contact.

2. The thermal bend actuator of claim 1 , wherein said beam element comprises one bend, which bends said beam element through 180 degrees.

3. The thermal bend actuator of claim 1 , wherein said beam element is a serpentine beam element comprising a plurality of bends.

4. The thermal bend actuator of claim 1 , wherein said conduction pad is titanium or aluminium pad.

5. The thermal bend actuator of claim 1 , wherein said beam element is comprised of a metal nitride, a mixed metal nitride or a metal alloy.

6. The thermal bend actuator of claim 1 , wherein said second beam is comprised of silicon oxide.

7. An inkjet nozzle assembly comprising:

a nozzle chamber having a nozzle opening and an ink inlet; and

a thermal bend actuator for ejecting ink through the nozzle opening, said actuator comprising:

a first active cantilever beam for connection to drive circuitry, said first beam comprising a bent planar beam element;

a second passive cantilever beam fused to the first beam, such that when a current is passed through the first beam, the first beam expands relative to the second beam resulting in bending of the actuator;

at least one conduction pad sandwiched between said first and second beams, said conduction pad being positioned at a bend region of said planar beam element so as to facilitate electrical conduction around said bend region; and

first and second adjacent electrode contacts positioned at one side of the actuator, wherein a first end of said beam element is connected to said first contact and a second end of said beam element is connected to said second contact.

8. The inkjet nozzle assembly of claim 7 , wherein the nozzle chamber comprises a floor and a roof having a moving portion, whereby actuation of said actuator moves said moving portion towards said floor.

9. The inkjet nozzle assembly of claim 8 , wherein the moving portion comprises the actuator.

10. The inkjet nozzle assembly of claim 9 , wherein the nozzle opening is defined in the moving portion, such that the nozzle opening is moveable relative to the floor.

11. The inkjet nozzle assembly of claim 9 , wherein the moving portion is moveable relative to the nozzle opening.

12. An inkjet printhead comprising a plurality of nozzle assemblies according to claim 7 .