Multifunctional thermosetting composites for dielectric barrier discharge plasma actuators: Integrated mechanical, electrical and flow performance

Surface dielectric barrier discharge (DBD) plasma actuators generate near-wall airflow through electrically driven electrohydrodynamic forcing, known as ionic wind. Here, thermosetting fibre-reinforced polymer laminates are investigated as structural dielectric layers for surface DBD plasma actuators, aiming to combine mechanical performance, electrical stability and induced-flow generation. Screening of three commercial resins identified the bio-based epoxy SR GreenPoxy 56/SD as the most energy-efficient dielectric, consuming 12 W during plasma discharge, compared with 14 and 26 W for epoxy AH and polyester. This matrix was reinforced with glass, Kevlar®, and flax fibres to evaluate effects on mechanical and functional performance. Characterisation included flexural testing, electrical power consumption, induced-flow velocity measurements, and Lissajous charge–voltage analysis to determine breakdown voltage and capacitance. All laminates generated plasma, with capacitance values between 13 and 29 pF depending on material and voltage. Glass-fibre-reinforced dielectric laminates showed the most stable response, combining the highest flexural strength and stiffness gains with reproducible induced-flow generation. Kevlar-reinforced dielectric laminates achieved the highest peak induced-flow velocity (2.3 m/s at 11 kVpp), whereas flax-based actuators showed lower robustness. Dielectric-thickness tailoring of the glass composite increased maximum induced velocity to 4.2 m/s, demonstrating active structural dielectric laminates for integrated flow control within lightweight composite architectures.