Imagine a drone that can stay in the air for hours without needing to land for a battery change.
That idea may be one step closer to reality thanks to a new technology that uses laser beams to wirelessly recharge drones while they are flying.
Researchers from the Civil Aviation University of China have developed a lightweight device that captures energy from a laser beam and turns it into electricity.
The study, published in the journal Matter & Light, shows that the system could one day help drones carry out much longer missions without frequent interruptions.
Wireless charging is already common for smartphones, smartwatches and wireless earbuds.
The researchers believe the same idea could be adapted for aircraft by sending energy through a carefully aimed laser beam instead of a charging cable.
The new system uses a special device called a perovskite laser cell-thermoelectric receiver. It is similar to a solar cell, but instead of collecting sunlight, it is designed to absorb energy from a laser. The perovskite layer converts the laser’s light into electricity that can power the drone.
The system also includes a thermoelectric layer that recovers some of the energy that would normally be lost as heat. This layer generates additional electricity by taking advantage of the temperature difference between the hot side facing the laser and the cooler side of the device.
However, heat quickly became a major challenge.
During testing with a powerful laser, the receiver reached temperatures of 80 to 90 degrees Celsius (176 to 194 degrees Fahrenheit). Such high temperatures reduce the efficiency of the system and could eventually damage its components if not properly controlled.
To solve this problem, the researchers added tiny nanocrystals that act as thermal barriers. These nanocrystals slow the movement of heat through the device, helping it stay cooler and maintain better performance during extended laser exposure.
The improved receiver achieved an energy conversion efficiency of 38.49% under a green laser. According to the researchers, this is one of the highest efficiencies reported for similar laser-powered systems.
The team also demonstrated how the technology could be integrated into a drone. They mounted the receiver beneath the wing of a stationary drone model and built small air channels inside the wing. When a green laser was directed at the receiver, it generated enough electricity to spin the drone’s propeller. The airflow through the wing also helped cool the receiver, further improving its performance.
Although the results are promising, the technology is still in its early stages. The current experiments were carried out on a stationary model rather than a flying drone. The next step will be testing the system on lightweight drones operating outdoors.
Researchers also need to solve several practical challenges before the technology can be widely used. Future systems must be able to accurately track moving drones with laser beams while ensuring that the lasers remain safe for people, animals and nearby aircraft.
Even with these hurdles, the research offers an exciting glimpse into the future of aviation.
If the remaining engineering challenges can be overcome, laser-powered wireless charging could allow drones to inspect forests, monitor disasters, deliver packages and perform many other tasks for much longer without stopping to recharge.
