Movement sensor in a micro electro-mechanical device

A micro electro-mechanical device incorporated in a liquid ejection device having a nozzle opening and a liquid receiving chamber, the micro electro-mechanical device comprising:

• an actuating arm having a first end coupled to the support structure and a second end that is movable with respect to the support structure, the actuating arm being formed in part from an electrically resistive material and being arranged to conduct heat inducing electrical current from a current source within the support structure to effect movement of the actuating arm to effect ejection of liquid from the chamber via said nozzle opening,
• a moving contact element formed integrally with the actuating arm adjacent the second end of the actuating arm,
• a fixed contact element formed integrally with the support structure and positioned to be contacted by the moving contact element when the actuating arm moves to an extent greater than that necessary to eject liquid from the chamber via said nozzle under the influence of the heat inducing electrical current, and
• electrical circuit elements formed within the support structure for detecting contact between the fixed contact element and the moving contact element.