Drones might soon be able to re-charge mid-flight thanks to Engineers at Imperial College London

Drones might soon be able to re-charge mid-flight thanks to Engineers at Imperial College London

Engineers at Imperial College London have showcased an efficient method for wirelessly transferring power to a drone mid-flight. Excitingly the breakthrough might have applications for other technologies – transferring power to devices or sensors used in healthcare or even further afield, on interplanetary missions.

The technology – at least in theory – would allow flying drones to stay airborne indefinitely by hovering over a ground support vehicle or recharging station. This opens up new commercial applications for drone technology as prolonged flight time would allow them to act in a more permanent capacity – potentially providing support for everything from surveillance to telecommunications.

The technique relies on inductive coupling – a method of charging that was originally demonstrated by inventor Nikola Tesla over 100 years ago.

Inductive coupling uses two copper coils which are electronically tuned to one another. This can allow the wireless exchange of power at a certain frequency. While Engineers have been experimenting with this technology for decades and had some success charging stationary objects they have never been able to use the technology successful for wirelessly powering flying objects.


Engineers at Imperial College London were able to demonstrate the concept by removing the batteries from an off-the-shelf mini-drone and wirelessly transferred power to it via inductive coupling. The team believe their demonstration is the first to show how this wireless charging method can be efficiently done with a drone.

The team inserted a made a foil ring into an off-the-shelf quadcopter drone, around 12 centimetres in diameter, which is a receiving antenna that encircles the drone’s casing. A transmitter on the ground made out of a circuit board was then connected to electronics and a power source, creating a magnetic field.

While the technique is still in an experimental stage (the teams’ drone had to fly only 10 centimetres above the magnetic field transmission source to receive a reliable stream of power) it is hoped that a commercially available product might be completed with a year.

Commercial applications could see drones using the technology for surveillance, reconnaissance missions, or search and rescue operations. Of course, the drone would still be limited by distance and the duration it can stay airborne without requiring a recharge.

Dr Samer Aldhaher, who is a researcher at the Department of Electrical and Electronic Engineering at Imperial College London explained that “there are a number of scenarios where wirelessly transferring power could improve drone technology. One option could see a ground support vehicle being used as a mobile charging station, where drones could hover over it and recharge, never having to leave the air”.

Drone are not the only sector that could benefit from better wireless charging. Application might also include powering or recharging sensors, healthcare devices and much further afield, on interplanetary missions.

An interesting application might also be for energy grids or large pieces of infrastructure which could benefit from having wireless charging ports to enable continuous monitoring of themselves. Professor Paul Mitcheson, from the Department of Electrical and Electronic Engineering at Imperial College London, explained that “a drone” could be used to “wirelessly transmit power to sensors on things such as bridges to monitor their structural integrity. This would cut out humans having to reach these difficult to access places to re-charge them”.

Professor Mitcheson went to explain that other application could include; “implantable miniature diagnostic medical devices, wirelessly powered from a source external to the body. This could enable new types of medical implants to be safely recharged, and reduce the battery size to make these implants less invasive” or even in future to “re-charge science equipment on Mars, increasing the lifetime of these billion dollar missions”.

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