A palm-sized drone, weighing less than a sheet of paper, has soared into the spotlight this week. This miniature marvel can fly continuously as long as it basks in sunlight, thanks to an ingenious motor developed by researchers.
The solar-powered drone, named CoulombFly, was created by a team at Beihang University in Beijing, renowned for their expertise in aeronautical and astronautical research. Remarkably, its size and weight are just one-tenth and one-six-hundredth of the previous smallest and lightest solar-powered aircraft, respectively.
Micro aerial vehicles like CoulombFly have a wide array of applications—from environmental monitoring to search and rescue operations—making them versatile tools in various fields. They excel in tasks such as capturing images, detecting objects, and transporting items in confined spaces. However, their limited flight duration has been a significant hurdle.
Traditional micro drones rely on electromagnetic motors to power their rotors. These tiny motors often overheat at high speeds, leading to a sharp decline in energy conversion efficiency. While natural sunlight is a potential energy source, smaller drones have less surface area to collect solar energy, limiting their power generation capabilities, explained lead researcher Qi Mingjing.
Published in the journal Nature on Thursday, the research highlights that drones weighing less than 10 grams have traditionally been limited to flight times of up to 10 minutes.
To overcome these challenges, Qi and his colleagues developed an electrostatic motor utilizing the Coulomb force—the interaction between electrically charged particles at rest—to generate continuous rotational motion. This innovative approach lends the drone its name, CoulombFly.
A demonstration showed the motor creating a circle of electric charges that produce a twisting force, causing a single blade to spin similarly to a helicopter rotor.
Co-author Peng Jinzhe highlighted the advantages of this motor: “This is because static electricity operates at high voltage and low current. The lower the current, the less heat it generates.” This design effectively reduces overheating issues common in traditional motors.
The study reports that for flying machines weighing less than five grams, the energy conversion efficiency powered by static electricity could exceed that of traditional electromagnetic motors by more than tenfold, requiring less than one-tenth of the power consumption for the same lift.
Before this breakthrough, the Robobee aircraft developed by Harvard University researchers in 2019 was considered a pinnacle in micro aerial vehicle technology. However, it required an artificial light source with intensity three times that of natural sunlight to sustain flight.
CoulombFly’s ability to achieve continuous flight solely relying on natural light marks a significant leap forward in the field, the researchers stated.
Professor Yan Xiaojun, one of the lead researchers, noted that after further development, this new drone technology could be applied in emergency rescue operations, narrow space detection, and other similar scenarios, enhancing capabilities where traditional drones fall short.
Reference(s):
Researchers develop tiny solar-powered drones for extended flight
cgtn.com
