ITMO-Developed WPT Room Can Charge Unlimited Number of Devices

The wireless chargers we’re familiar with today can only function when the device being charged is in close contact with the special transmitting stand. Inside these stands are transmitting coils that generate an alternating magnetic field. This field is picked up by the receiving coil inside a smartphone (or another device) and converted into an electric current. This solution is inconvenient because the charging device cannot be used fully; what’s more, different devices require their own separate transmitters. One promising avenue for the future of WPT is the development of “charging rooms” where several devices can be charged simultaneously.

A team of physicists from ITMO University have created a WPT room that is capable of charging an unlimited number of devices using a 3D resonator. Unlike its counterparts, the new technology can boast a homogeneous magnetic field and thus can charge devices located anywhere in the room with equal efficiency. This was made possible thanks to a special geometry of the transmitter – a Helmholtz coil made of two rings.

The prototype is a 4x4x2.5 meter space; any device placed inside it will be charged. As WPT occurs at a specific frequency (1 MHz), a separate receiver device for power transfer is needed for charging to occur – it could take the form of, for instance, a phone case. Connected to power via a special generator, the room consumes around 100-200 Watts, which is the amount of energy required by a PC or a large TV.

The room is compatible with a great number of devices: smartphones, lights, smart home sensors, laptops, PCs, or fans. Importantly, the more devices there are inside it, the higher the room’s efficiency level – which is the ratio between the power needed to charge the devices inside and the power used to maintain the room’s functionality. Among the technology’s potential applications are items used in warehouses, including wearables, smart homes, industrial sensors, and robotic systems. 

Another important detail is that the room is safe for humans. Its specific absorption rate of electromagnetic energy, which determines the electromagnetic field’s harmful effects on humans, is several dozen times lower than the maximum permissible limits set by international standards. The electric field, meanwhile, is confined to an enclosed perimeter zone around the resonator and does not affect humans.

“Our technology can be adapted to various designs and shapes and integrated into different spaces. Also, in the future we will be assembling a new room, where we will focus on polarization – the direction of the magnetic field. Currently, we only have horizontal polarization, meaning that the devices inside can only be charged when positioned this way; we want to add other positioning options,” shared Aigerim Jandaliyeva, one of the project’s authors and a junior researcher at ITMO’s Research Laboratory for Wireless Technologies.

The new technology is the result of years of research. In 2022, ITMO scientists presented a wireless charging box that could charge up to three devices placed anywhere inside it with equal efficiency; recently, the team developed the first Russian wireless charging technology for IoT and smart home devices. In 2023, experts from ITMO and charging systems manufacturer Yablochkov tested Russia’s first wireless electric car charger.