Thermal bend actuator comprising conduction pads

1. A thermal bend actuator comprising:

a first active cantilever beam for connection to drive circuitry, said first beam comprising a planar beam element having at least one bend;

a second passive cantilever beam mechanically cooperating with 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; and

at least one conduction pad positioned at a bend region of said beam element; and

first and second electrode contacts, 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,

wherein said at least one conduction pad is configured to facilitate electrical conduction in said at least one bend region.

2. The thermal bend actuator of claim 1 , wherein said at least one conduction pad is sandwiched between said first and second beams.

3. The thermal bend actuator of claim 1 , wherein said first beam is spaced apart from said second beam.

4. The thermal bend actuator of claim 1 , wherein at least part of said first beam is fused or bonded to said second beam.

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

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

7. The thermal bend actuator of claim 1 , wherein said first and second contacts are adjacent each other, and the beam element is bent for connection of said first and second ends to respective first and second contacts.

8. The thermal bend actuator of claim 1 , wherein said at least one conduction pad is a metal pad.

9. The thermal bend actuator of claim 8 , wherein said metal is titanium or aluminium.

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

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

12. 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 planar beam element having at least one bend; and

a second passive cantilever beam mechanically cooperating with 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 conductive pad positioned at a bend region of said first beam; and

first and second electrode contacts, 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,

wherein said conductive pad is configured to facilitate electrical conduction in said bend region.

13. The inkjet nozzle assembly of claim 12 , 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.

14. The inkjet nozzle assembly of claim 13 , wherein the moving portion comprises the actuator.

15. The inkjet nozzle assembly of claim 13 , wherein the nozzle opening is defined in the moving portion, such that the nozzle opening is moveable relative to the floor.

16. The inkjet nozzle assembly of claim 13 , wherein the moving portion is moveable relative to the nozzle opening.

17. The inkjet nozzle assembly of claim 12 , wherein said first and second contacts are adjacent each other, and the beam element is bent for connection of said first and second ends to respective first and second contacts.

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