Wireless charging is in its infancy, but at least you can charge your devices without plugging them into the wall. Only problem is you need to buy the charging pad, but why would you buy the pad, when you still have to charge it by plugging into the wall? Either way, the transfer distance and efficiencies still fall far short of anything current market expectations demand.
Well, ITMO University researchers have not only designed a new charging system that can maintain up to 80% transfer efficiency, but it can do it from up to 20 cm away from the power source.
The current Wireless Power Consortium standard only covers up to 4 cm, and most solutions still require direct contact and perfect alignment.
Most wireless power transfer relies on the resonance coupling, where two resonant copper coils wirelessly exchange power by resonating at the same frequency.
ITMO uses the same basic principle, but they replaced the copper coils with spherical dielectric resonators made of ceramic material with high permittivity and low loss. This helped avoid losses, and led to higher efficiency.
They also used a higher-order resonant frequency mode called magnetic quadrupole mode. By operating at quadrupole, rather than dipole mode, they not only increased efficiency, but also made it less sensitive to the orientation of the transmitter relative to the receiver.
The possibility of random orientation is a huge step closer to more practical wireless charging stations.