Disney Research created a method to wirelessly transmit power through a room, allowing electronic devices to charge quickly via connected Wi-Fi hotspots, removing the need for electrical cords and charging cradles.
Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within.
A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.
Here, Disney included all data for reproducing the experimental validation curves of Fig. 4a–d of the PLOS One article entitled “Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer”. This data set includes measured, simulated, and analytically computed electric and magnetic fields, as well as all S-parameter data for reproducing the efficiency curves of panels d and e in Fig. 4 of the article. We further include a Comsol Multiphysics (.mph file) model that can be used for reproducing simulations for the QSCR designed and tested in the article.
By inducing electrical currents in the metalized walls, floor, and ceiling, the QSCR method creates magnetic fields that spread throughout the room. In turn, power can be diffused smoothly to receive coils that work at the same resonant frequency as the magnetic fields. Discrete capacitors channel the induced currents and isolate any potential for harmful electrical fields.
During the test, a copper pole was placed in the center of the room, and a small gap was placed in the pole, where discrete capacitors were inserted. Those capacitors set the electromagnetic frequency of the structure and enclose the electric fields. Devices that operate at a low megahertz frequency can collect power from anywhere in the room. Magnetic waves at that frequency don’t interact with metals, thus do not affect other objects in the room.
Credit : https://www.disneyresearch.com/