Ink jet nozzle to eject ink

1. A printer including an array of ink jet nozzles to eject ink, each of said nozzles comprising:

a body defining a chamber in which the ink to be ejected can be located, the body having an aperture through which the ink can be ejected; and

an actuator member having shape memory and extending from the body into the chamber, the actuator member being arcuate in shape when in a quiescent state and straightening in shape when actuated;

wherein the actuator member is located in the chamber so as to push ink through the aperture when actuated to thereby eject ink from the body.

2. A printer according to claim 1 , further comprising an actuator for actuating the actuator member.

3. A printer according to claim 2 , wherein:

the actuator member comprises a heating element;

the actuator comprises driving circuitry which is electrically coupled to the heating element; and

the heating element straightens when heated by the driving circuitry and curls when cooled.

4. A printer according to claim 3 , wherein the actuator member further comprises two protective layers located on opposing sides of the heating element.

5. A printer according to claim 3 , wherein the driving circuitry is formed on a CMOS layer of the body.

6. A printer according to claim 3 , further comprising metal interconnects for electrically coupling the driving circuitry to the heating element.

7. A printer according to claim 1 , wherein the body comprises a plurality of layers.