Influence of dielectric thickness and electrode structure on the ion wind generation by micro fabricated plasma actuators

Abstract

Surface dielectric barrier discharges are investigated in order to explore the combined effects of barrier thickness and microstructure of the exposed electrode on the ion wind generation. Actuators with straight and structured high voltage electrodes with characteristic sizes of 200 and 250 µm and dielectric thicknesses of 0.5, 1 and 2 mm are compared. It is observed that: i) actuator efficiency of ion wind generation strongly depends on the applied voltage amplitude; ii) operation voltage depends on the dielectric thickness logarithmically; iii) electrode microstructure slightly increases the dynamic pressure (few percent in maximum), however the effect decreases with thicker dielectrics and smaller electrode structures; iv) the pattern of the most intensive discharge parts as well as the dielectric erosion repeats the regular structure of the electrodes down to 200 µm. Several identical samples are tested during different days to estimate the impact of the air humidity and the degradation of the dielectric. The microscale precision of the sample manufacture was accomplished by a commercial facility for printed circuit boards.

Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge

“…The luminosity of the discharge is decreasing with the distance from the electrodes as it is typical for SDBDs (see, e.g., Hink et. al [34]). The discharges occupy the whole area above the ground electrode at 2.8 kV rms .…”

“…Note that the size of the observed samples restricts the inclination angle to 55°f or technical reasons that makes the width of the MEMS electrodes less noticeable. On the basis of our previous research [32,34] a second electrode pattern G2 (right side of Figure 3) was implemented to investigate the impact of the ionic wind. The green arrows in Figure 3 indicate the generated ionic wind direction.…”

“…The up and down cycle of the voltage-sweep were performed to visualize a possible degradation of the samples due to the erosion of either the electrodes or the dielectric. The power was scaled to the effective length of the high-voltage electrodes (L = 0.696 m) which was measured disregarding the microstructure as introduced by Hink et al [34]. The power of a freely expanding SDBD increases with a cubic behavior of the applied voltage (P ∼ V 3 ), see [43].…”

“…A similar power voltage dependence is also obtained for the FR-4 sample and the measured values agree for both materials within the experimental errors. The dissipated power at the zirconia sample has a stronger dependency on the voltage due to the extremely thin dielectric with a higher dielectric constant [34,40].…”

“…A further challenge of the technology development was the reduction of the discharge operation voltage to ensure a safer operation of the SDBDs by increasing electromagnetic compatibility. This can be achieved by reducing the dielectric thickness [34]. For this reason SDBDs manufactured on 500 µm thick borofloat glass and 150 µm zirconia ceramic substrates were examined.…”