A device similar in shape and size to a flat screen TV could soon be employed in remotely charging any other device within its line of sight, according to new research. The technology required to build this device already exists in terms of accessibility and creating this wireless power transfer machine is only a matter of taking the time to designing it.
The research, published Oct. 23, 2016 in the journal American Institute of Physics, notes that wireless power transfer (WPT) has been a popular subject of research. The new study employed a beamed WPT scheme created employing a dynamically reconfigurable aperture transferring power to receiving devices within the Fresnel region.
The End Of Power Chargers
"The necessary amplitude and phase distribution of the field imposed over the aperture can be determined in a holographic sense, by interfering a hypothetical point source located at the receiver location with a plane wave at the aperture location. While conventional technologies, such as phased arrays, can achieve the required control over phase and amplitude, they typically do so at a high cost; alternatively, metasurface apertures can achieve dynamic focusing with potentially lower cost," noted the study abstract.
The research found that the approximate design formulas are derived from the Gaussian optics approximation, and give relatively stable estimates of the system performance, in terms of both efficiency and coverage.
Wireless charging systems have already been created, they are generally used to charge power speakers, phones or tablets. However, these technologies require special platforms and need to be placed in the vicinity of the charger.
"Whether it's headphones, cell phones, watches, or even your mouse and keyboard, a major irritation for consumers is the hassle of being tethered to cords to recharge batteries. And of course, they always run dry at the worst possible moment. Our proposed system would be able to automatically and continuously charge any device anywhere within a room, making dead batteries a thing of the past," noted David Smith, professor and chair of the Department of Electrical and Computer Engineering at Duke.
The reason why gadgets can only receive power when placed close to the charging station is that the system through which this type of charging works is a resonant magnetic near-field employed to the energy transfer. Magnetic fields are believed to be lacking dangers when it comes to human exposure, which is why they are generally used in power transfer out of convenience.
Wireless Power Transfer, Soon-To-Be-Available Technology
The magnetic near-field, however, cannot support power transfer over bigger distances because the coupling between the source and the gadget receiving power drops when exceeding a given distance. This new research proposes a WPT system which would permit charging wireless on a much larger distance than the usual ones already available on the market, due to a more permissive frequency.
The challenge of developing the technology which would allow this type of WPT lies in finding low cost, very powerful materials. These would also have to be an efficient and reliable electromagnetic energy source. However, according to the authors of the study, these challenges will soon be addressed and the team will find the most optimal solution.
