Energy, power, and actuation systems for sustained untethered flight in gram-scale aerial vehicles

Gram-scale micro aerial vehicles have a flight time of less than 10 min, which is far from long-duration or even unlimited endurance, thus significantly constraining their application scenarios. To address the challenges faced by gram-scale micro aerial vehicles for sustained untethered flight, this article examines recent advances in energy, power, and actuation systems and outlines environmental energy-harvesting strategies. Major technological bottlenecks are identified, and key design principles are proposed, including the selection of actuators with high lift-to-power ratios, the prioritization of lightweight and efficient energy and power systems, and the integrated structural design. These insights provide guidance for realizing practical, long-duration flight.