  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.
In this work, 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 thrust densities comparable to commercial propulsors.
An optimized five-stage device attains a thrust density of about 18 N/m$^2$ at
a thrust efficiency of about 2 mN/W, among the highest values ever measured at
this scale. We further show how this type of thruster can be integrated under
the wings of a MAV-scale fixed wing platform, pointing towards future use as a
distributed propulsion system.
