The CoulombFly drone weighs less than an A4 sheet of paper, has a wingspan of about 20 cm, and can fly for extended periods.
Test flight of the CoulombFly drone. (Video: Nature).
A team of scientists from Beijing University of Aeronautics and Astronautics has successfully developed the CoulombFly, the world’s smallest and lightest solar-powered flying vehicle, as reported by Interesting Engineering on July 18. The research was published in the journal Nature.
The CoulombFly weighs only about 4 grams, lighter than an A4 sheet of paper, with a wingspan of approximately 20 cm—about the size of a hand. It is 10 times smaller and 600 times lighter than the previous smallest solar-powered drone. This new drone model utilizes solar cells to generate electricity, creating an electric field between oppositely charged plates arranged in a circular pattern. The opposite charges act like repelling magnets, generating torque to spin the propeller. This process creates enough torque to lift the drone off the ground.
The CoulombFly boasts enhanced lifting efficiency, achieving 30.7 grams per watt and consuming only 0.568 watts to fly in the air. This allows it to operate continuously under natural sunlight.
Limited flight time is a significant challenge for ultra-small flying vehicles, especially those weighing under 10 grams, which typically have flight durations of no more than 10 minutes. However, the CoulombFly has addressed this issue. The research team states that each component is designed to balance efficiency with lightweight construction, allowing the drone to perform remote monitoring tasks for extended periods.
The CoulombFly weighs only about 4 grams, lighter than an A4 sheet of paper.
During test flights, the CoulombFly takes off within just 1 second after the solar cells are exposed to light. Currently, it can fly wirelessly for 1 hour at a height of 15 cm, carrying 2 grams of sensors or small controllers. Although these results may sound modest, the experts believe that future design improvements will enhance the endurance and payload capacity of the drone.
Scientists have suggested several improvements, including increasing the motor’s torque, enhancing the lift of the propellers, integrating solar cells into structural components, and boosting the performance of the voltage converter. This tiny drone model could be invaluable for disaster relief efforts, conducting patrols in confined spaces, and collecting information.
