Patent ID: 7661795

Claim:
A nozzle device for an inkjet printer, the nozzle device comprising: a support structure defining an ink inlet chamber connected to a source of ink; an elongate actuating arm cantilevered relative to the support structure; and a nozzle chamber structure defining a nozzle chamber for receiving ink from the ink inlet chamber, the nozzle chamber structure comprising a static portion extending from the support structure and defining a nozzle opening through which ink in the nozzle chamber is ejected, the nozzle chamber structure further comprising a movable wall portion mounted to the actuating arm between its ends so that the cantilevered actuating arm terminates in a free end within the nozzle chamber so that, upon actuation of the actuating arm, the free end of the actuating arm moves within the nozzle chamber and ejects ink therein through the nozzle opening wherein the actuating arm comprises: an active portion connected electrically to a current source, and which heats and expands upon activation of the current source, and a passive portion which is electrically isolated from the current source and is mechanically coupled to the active portion via at least one separating element so that, upon activation of the current source, differential expansion of the active and passive portions causes the actuating arm to bend.