Laser power system moves drone charging closer to mid-flight operation
Chinese researchers have demonstrated a laser charging system that could keep drones powered in flight. The prototype uses a high-powered laser beam aimed at a receiver mounted under a drone wing, where the light is converted into electricity to drive the aircraft’s propellers.
The work was carried out by researchers at the Civil Aviation University of China and Tsinghua University and detailed in a study published July 29 in Matter & Light. The system was tested on a drone model, not a full aircraft, but the team designed it around the engineering demands of flight. That included integration with an airframe, power conversion during operation and thermal control.
The receiver is a perovskite laser cell-thermoelectric tandem device, known as PLC-TE. Perovskite is used in advanced solar-cell research because its crystal structure can capture more of the light spectrum than silicon. Under a green laser, the receiver converted 38.49% of incoming light into electricity, above the 34% peak reported for perovskite-silicon tandem cells by the U.S. Department of Energy.
Heat quickly emerged as the main obstacle. During high-power laser testing, thermal imaging showed temperatures of 80 to 90 degrees Celsius, or 176 to 194 degrees Fahrenheit, high enough to cut efficiency and complicate use on a lightweight aircraft. The researchers added antimony triselenide nanocrystals to the PLC-TE design as a thermal barrier, while airflow from the drone’s propeller helped cool the receiver during operation.
The researchers identified reconnaissance, logistics and disaster relief as potential uses, along with forest monitoring and package delivery. They said the next step is testing the device on a real lightweight drone outdoors, but precise real-time tracking will be needed to keep the laser locked onto the receiver during flight. If those hurdles are cleared, laser wireless power could sharply reduce battery-related landings and extend UAV missions far beyond today’s limits.