Scientists Develop Solar-Powered Drone Weighing Less Than a Nickel
Chinese scientists have developed a tiny, solar-powered drone that is by far the smallest and lightest of its kind.
Dubbed the CoulombFly, the minuscule drone weighs only 4.21 grams — less than a United States nickel — and its wingspan is a mere 20 centimeters (7.9 inches). Per IEEE Spectrum, the CoulombFly is 600 times lighter and 10 times smaller than the previous record-holder for the most miniature solar-powered aircraft.
Considered an ultralight micro aerial vehicle (MAV), the new drone is in a category of bird-sized (or smaller) aircraft that could be useful for various applications. Unfortunately, a significant issue of these types of vehicles is their limited flight time. Typically, an MAV will only run for about 30 minutes, and an ultralight MAV, which weighs under 10 grams, will only run for under 10 minutes.
A solution to this issue would be powering an MAV with a consistent energy source like sunlight to improve flight times. Researchers in Beijing now believe they’ve developed the first MAV capable of sustained flight through solar power.
According to Mingjing Qi — a professor of energy and power engineering at Beihang University and one of the scientists who built CoulombFly — previous attempts at solar-powered MAVs relied on electromagnetic motors to achieve lift, which use magnets to propel the motor.
However, the smaller the craft gets, the more inefficient these motors are due to greater friction and energy loss. In addition, the smaller a craft, the less surface area it has to collect sunlight.
The CoulombFly instead uses an electrostatic motor, which produces motion through electrostatic fields. Even though these motors are typically not used for propulsion, the motor used in the CoulombFly is two to three times more efficient in lifting the craft than other MAV motors.
Qi believes that this new propulsion system can accommodate today’s smallest sensors and cameras, which could allow a drone like this to have a wide range of applications and uses. The team is also exploring the possibilities of adding a lithium battery to the rig, which would allow it to store power from the solar cells and operate when the Sun isn’t out.
The scientists published their complete research in Nature last month.
Image credit: Wei Shen, Jinzhe Peng and Mingjing Qi
