Micro-electromechanical device with built-in fault detection

摘要

A micro-electromechanical nozzle arrangement includes a substrate. Drive circuitry is positioned on the substrate. An elongate actuator is fixed at one end to the substrate to be electrically connected to the drive circuitry so that an opposite end is reciprocally displaceable with respect to the substrate on receipt of a current pulse from the drive circuitry. A nozzle chamber structure is positioned on the substrate and defines a nozzle chamber and an ink ejection port in fluid communication with the nozzle chamber. A fluid ejection member is positioned in the nozzle chamber and is connected to the opposite end of the actuator so that ink is ejected from the nozzle chamber when the fluid ejection member is displaced by the actuator. A switch assembly is arranged on the actuator and the substrate to be electrically connected to the drive circuitry so that the switch closes a circuit and the drive circuitry generates an electrical current when the elongate actuator is displaced a predetermined extent.