Micro-electromechanical fluid ejection device with actuator guide formations

摘要

A micro-electromechanical fluid ejection device includes a substrate containing drive circuitry. A nozzle chamber structure is positioned on the substrate and defines a nozzle chamber and a fluid ejection port in fluid communication with the nozzle chamber. An elongate actuator is fast with the substrate at a fixed end. The elongate actuator has a laminated structure of at least two layers with one of the layers defining an electrical heating circuit in electrical contact with the drive circuitry to be heated and to expand on receipt of an electrical signal from the drive circuitry and to cool and contract on termination of the signal, thereby to generate reciprocal movement of the actuator. A fluid ejecting member is fast with an opposite end of the actuator and is positioned in the nozzle chamber to eject fluid from the fluid ejection port on said reciprocal movement of the actuator. The actuator extends through the nozzle chamber structure and the actuator and nozzle chamber structure define complementary guide formations which are shaped so that movement of the fluid ejecting member is substantially linear.