Researchers developed a new wireless charging transmitter that can charge multiple devices in close proximity at very high efficiency of 90%.
Wireless charging technologies are making lives easier by not relying on plugs, sockets, and charging pads to power up. Researchers across the globe are trying to make truly wireless solutions, but they all employ sophisticated technologies that involve detecting presence and position of the phone or charging device to be able to send energy in its direction, usually done with cameras or sensors, adding bulk and cost to the device.
Researchers from the Aalto University have developed a new wireless transmitter that bypasses the need for a detection sensor, and transfers power channels in all directions, automatically tuning channels when receiving devices are in motion. Multiple devices like phones, laptops, tablets, etc. can charge directly from this transmitter–without ever being in physical contact or being brought to a specific place. The work was published in IEEE Transactions on Industrial Electronics on July 21, 2021.
“What sets this transmitter apart is that it’s self-tuning, which means you don’t need complex electronics to connect with receivers embedded in devices. Since it self-tunes, you can also move the device freely within a wide charging range,” explains Prasad Jayathurathnage, a postdoctoral researcher at Aalto University.
The researchers used coils to transmit power just like other wireless technologies, and by winding the coils in a specific way, they created two kinds of electromagnetic fields: one going outwards and the other around. These fields couple the receiver and transmitter to achieve efficient power transfer.
The developed transmitter is currently 90% efficient at up to 20 centimeter distance. “For now, the maximum range at peak efficiency is dependent on the size of the transmitter and receiver. With the right engineering, we could shrink them down,” Jayathurathnage says.
The team has successfully demonstrated the proof of concept, but safety tests are needed to confirm that the transmitter does not emit electromagnetic waves harmful to humans.
The researchers believe that this newly developed technology can be the true key to truly wireless charging.
“True wireless charging means more personal freedom. You won’t have to worry about where you put your phone or whether you remembered to plug it in,” says Jayathurathnage.