Improvement of ultrasonic atomizer method for deposition of gas-sensing film on QCM

We report on improved ultrasonic atomizer method of depositing the sensing films on quartz crystal microbalance (QCM) sensors. The main objectives of the present work were minimizing the sensor-to-sensor response variation, improving the sensing film stability, and reducing amount of materials used during coating (reducing time of coating). In order to achieve the goals, we have redesigned and refabricated large parts of the atomizer system reported previously. The main principle of the operation—deposition of the fine mist generated by the ultrasonic device remained unchanged. The largest modifications encompass introduction of the new, sealed deposition chamber, considerable reduction of the flow resistance, and control over the flow rates of the mist and air streams in the system. The paper reports the new configuration of the ultrasonic atomizer method, optimization of the atomizer system performance (deposition parameters) and the results of improved quality of sensors fabricated using the new system.