A New Way to Power Drones
Imagine a delivery drone that never needs to touch the ground to swap a depleted battery. Researchers in China have taken a bold step toward that vision by demonstrating a lightweight receiver that harvests energy from a directed laser beam and converts it into usable electricity while the aircraft stays aloft. The concept builds on the familiar idea of wireless charging for phones and wearables, but pushes the technology into the sky where weight, heat and efficiency are far more demanding.
How the Laser‑Powered Receiver Works
The core of the system is a perovskite‑laser‑thermo‑electric (PLC‑TE) device. Unlike a conventional solar cell that is tuned for sunlight, this hybrid cell is optimized for a narrow‑band laser wavelength—typically a green laser in the laboratory tests. The perovskite layer absorbs the photons and generates an electric current, while an adjoining thermoelectric layer captures the heat that would otherwise be wasted. The larger the temperature gradient between the hot side (exposed to the laser) and the cold side, the more additional voltage the thermoelectric section contributes.
Cooling the Heat: Nanocrystal Barriers
Powerful lasers inevitably raise the temperature of the receiver. In early experiments the surface reached 80‑90 °C, threatening both performance and component longevity. To mitigate this, the team embedded specially engineered nanocrystals that act as thermal insulators. These crystals slow the flow of heat away from the active layers, creating a protective barrier that keeps the device within a safe operating window even during prolonged exposure.
Efficiency Milestones
Under a green laser the prototype achieved a conversion efficiency of 38.49 %—one of the highest reported for laser‑to‑electricity systems of this type. This figure reflects the combined contribution of the photovoltaic and thermoelectric mechanisms, and it demonstrates that the nanocrystal heat barrier does not sacrifice power output.
From Bench to Wing
To prove that the concept can survive the aerodynamic environment, engineers mounted the PLC‑TE module on the wing of a stationary drone mock‑up. The wing incorporated custom air channels that directed airflow across the cold side of the thermoelectric stack, providing passive cooling that further boosted efficiency. When the green laser was switched on, the propeller spun up, confirming that the harvested energy was sufficient to drive the motor.
Next Steps: Real‑World Flight Tests
The laboratory success is only the first milestone. The research team plans a maiden outdoor flight using a lightweight UAV equipped with the laser receiver. Key challenges remain: maintaining precise laser alignment with a moving target, ensuring the system can handle wind‑induced vibrations, and integrating safety protocols to prevent accidental exposure to high‑power beams. If these hurdles are cleared, the technology could revolutionize sectors that rely on long‑duration UAV missions—forest monitoring, disaster assessment, and even package delivery.
While the concept is still in its infancy, the combination of perovskite photovoltaics, thermoelectric harvesting, and nanocrystal thermal management offers a compelling pathway to extend drone endurance without the logistical burden of frequent landings.
Source: https://scientias.nl/vliegende-drones-opladen-met-een-laserstraal-is-het-accuprobleem-opgelost/
