A low power, small, electrostatically-driven commercial inkjet head

Si-micromachined electrostatically actuated inkjet head has been developed for the electric calculator printer. It is the first commercial device of this kind. The electrostatic actuator comprises a Si pressure plate and a corresponding transparent ITO electrode which is parallel to the pressure plate, they are assembled to keep the air gap between them within 0.2±0.015 μm. The driving voltage is 38 V and a driving frequency is up to 3 kHz. The inkjet head have achieved the uniform ink ejection. The weight of an ink drop is kept more than 0.12 μg under the condition of the frequency range up to 3 kHz and the temperature range of 10 to 40°C; this satisfies one of the most critical head specifications. The calculated average current consumption is only 50 μA/nozzle. Because of the full-batch fabrication and the electrostatic actuation, the inkjet head is low power, thin and small