Optimized self-excited electrostatic actuators with insulated-electrodes configuration for micro air vehicles

Flapping micro air vehicles (MAVs) possess advantageous characteristics such as agility, stability, and maneuverability, making them potential candidates for search and rescue operations in confined spaces. However, the development of electrostatic flapping MAVs faces a significant challenge due to the limited availability of actuators with high power density. In this study, we present optimized self-excited electrostatic actuators featuring an insulated-electrodes configuration that enables enhanced operating voltage and increased power density. To improve upon previous designs, our new actuator incorporates a pair of auxiliary electrodes, while the main electrodes and cantilever are covered with insulating polyimide films. A fabrication method is devised to ensure precise construction of the actuator while maintaining the desired conductive and insulating properties of each component. The optimized actuator demonstrates notable improvements, including a 20.9% increase in operating voltage to 2600 volts, an electrostatic force of up to 1.2 mN, and a heightened power density of 24.7 W/kg. Building upon this optimized actuator, we propose a prototype of a flapping MAV capable of generating a lift force of 117.6 μN, approximately 19% of its self-weight. These results contribute to the advancement of electrostatic flapping MAVs and offer prospects for future breakthroughs in overcoming gravitational forces through geometry optimization.