High Aspect Ratio Multi-Stage Ducted Electroaerodynamic Thrusters for Micro Air Vehicle Propulsion

Electroaerodynamic propulsion, where force is produced through collisions between electrostatically accelerated ions and neutral air molecules, is an attractive alternative to propeller- and flapping wing-based methods for micro air vehicle (MAV) flight due to its silent and solid-state nature. One major barrier to adoption is its limited thrust efficiency at useful disk loading levels. Ducted actuators comprising multiple serially-integrated acceleration stages are a potential solution, allowing individual stages to operate at higher efficiency while maintaining a useful total thrust, and potentially improving efficiency through various aerodynamic and fluid dynamic mechanisms. Here, we investigate the effects of duct and emitter electrode geometries on actuator performance, then show how a combination of increasing cross-sectional aspect ratio and serial integration of multiple stages can be used to produce overall thrusts comparable to state-of-the-art flapping wing robots. A five-stage device is shown to reach a thrust density of about 18 N/m $^{2}$ , an order of magnitude higher than what has previously been achieved at this scale, with the same measured thrust efficiency as reported in prior work. We also show how a high aspect ratio multi-stage ducted thruster could be integrated under the wings of a MAV-scale platform, pointing towards use as a distributed propulsion system in future work.