Wi-Fi charging is possible, but so far ineffective – the opinion of engineers and scientists
The theory that Wi-Fi signals can be used to charge the phone was not completely correct. American scientists have developed a device that can convert energy from the waves of wireless Internet into direct current for power. But in practice it became clear that even with the receipt of the maximum possible amount of power, it would take several days to recharge the iPhone.
Due to which electrical signals are transformed into energy
A device known as rectenna or a rectified antenna can convert alternating current into direct current. It catches the electromagnetic radiation of an object, converts its current into alternating one and passes it through a diode. The latter, in turn, changes it to power the devices or to use it for other electrical purposes. This rectenna was recently created by experts at the Massachusetts University of Technology.
However, the history of such antennas dates back to the 60s of the XX century. Even then, scientists and visionaries were thinking about how to transfer the surrounding energy over a long distance. Of course, then it was not produced by Wi-Fi sources, but by other electronic objects.
Why Wi-Fi charging is not effective enough
Rektennas have evolved noticeably in our time. For example, in 2015, an innovative nanotube optical antenna was presented. Nevertheless, the effectiveness of such developments is still low. They noticeably lose power in solar panels.
Even the new device of MIT engineers, despite its innovativeness, is not able to solve the problem of charging power specifically for mobile phones. A flexible antenna created at MIT can pick up waves associated with Wi-FI signals and convert them to alternating current. Instead of the traditional diode, experts have created a two-dimensional thin semiconductor. It is capable of generating enough voltage to power small sensors and medical devices.
But for charging the phone there are not enough rectenna options yet. Even with the condition of receiving all possible power from the waves, it takes several days to charge the iPhone battery.
In this regard, engineers expect that wireless charging systems for large devices will be built on induction technologies that can power gadgets at a distance of up to a meter if there is no barrier object between them.