Printhead nozzle arrangement with a micro-electromechanical shape memory alloy based actuator

摘要

A printhead nozzle arrangement includes a substrate. Drive circuitry is positioned on the substrate. A nozzle chamber structure is arranged on the substrate and defines a nozzle chamber in fluid communication with a supply of ink and an ink ejection port in fluid communication with the nozzle chamber. An actuator is connected to the drive circuitry and is operatively positioned with respect to the nozzle chamber. The actuator is reciprocally deformable between a quiescent condition and an active condition to eject ink from the ink ejection port. At least a portion of the actuator is in the form of a shape memory alloy which is in a pre-stressed martensitic phase when the actuator is in the quiescent condition and in an austenitic phase when the actuator is in the active condition so that cyclic phase changes generate the reciprocal movement.