Electrode material degradation monitoring for durable dielectric barrier discharge plasma actuators manufacturing

This study aims to develop effcient, reproducible and durable plasma actuators. Thin metal deposition and high manufacturing reliability control were gained by adopting the photographic technique. As dielectric material degradation and electrodes corrosion are significant issues, emphasis was put in selecting materials that could withstand the plasma environment. Gold was selected as electrode material for all the geometric configurations. A Schott alkali-free borosilicate glass substrate was chosen as dielectric because of its resis- tance to material degradation in the plasma environment. Measurements of the actuator power consumption and capacitance were used to quantify the change in actuator performance over time. Moreover, scanning electron microscope images and energy dispersive X-ray spectroscopy analysis were utilised on the used devices to help explain the observed changes in actuator performance. After usage, unexpected degradation effects were ob- served on the gold electrodes, in both the front side and back side of each actuator. The electrode edges retracted and residual gold remained on the glass substrate. In particu- lar, the exposed electrode width reduced by up to approximately 50%, depending on the actuator working conditions. Moreover, the morphology of the electrode surfaces changed and melting/crystalline reorganization of the gold layer was observed at the borders of the shrunk electrodes. As a consequence, a decrease of the actuator cold capacitance with age was evident. Furthermore, a rise in the actuator power consumption and effective capac- itance was noted with increasing actuation time. At the same time, the actuator aging process produced an increase in its effective capacitance at a given dissipated powe