High-thrust ultralight ion wind engine toward controllable aerial microrobots

The ion wind engine, an innovative propulsion system, transforms ion energy into mechanical thrust, offering unique advantages such as low noise, no moving parts, a compact form factor, and a superior thrust-to-weight ratio. This technology shows exceptional promise for powering miniaturized robotic systems, particularly one of the most challenging types—flying microrobots. In this study, we developed a three-dimensional electrohydrodynamic (EHD) model to investigate a needle-to-plane ion wind engine, integrating the coupled effects of electrostatic fields, ion transport, and fluid dynamics. Using simulation-driven insights, we optimized the engine’s structure, achieving enhanced performance with a four-collector configuration weighing 18.1 mg. Experimental validation through Schlieren imaging and thrust measurements confirmed high wind speeds and a thrust of 0.66 mN, yielding a thrust per unit volume of 261 N/m3 and a thrust-to-weight ratio of 3.7. As a proof-of-concept, we designed and fabricated a microrobot powered by the optimized ion wind engine, demonstrating precise flight attitude control via independent engine operation. These findings highlight the potential of multi-engine ion wind systems for advancing microrobot flight dynamics, with significant implications for the design of next-generation microscale aerial vehicles.