Charging is a mode of transferring power to the devices we use most. From Electric vehicles to the smartphones we hold to so dearly. But the mode of transmission has always brought a lot of controversy. Some prefer cable charging due to its efficiency while others prefer the convenience of wireless charging.
Cable charging has always provided the most efficient and faster mode of charging simply due to minimal energy loss during transmission unlike in wireless charging. The reason why wireless charging is not as fast as cable charging is simply because of lack of efficiency.
Wireless charging mainly relies on an electromagnetic coil, an induction coil in the transmitter (wireless charging pad) and a coil in the receiver which in this case is your smartphone. The transmitter works by creating a magnetic field between both devices.
The coil in your smartphone in turn receives the energy and converts in into electricity which ends up charging your phone. However, there are some limitations to wireless charging. Two of the biggest ones are efficiency and speed. Let me explain. Until now, the fastest wireless power delivery was at around 15 watts as compared to cable charging which is 120 watts. (In mobile phones)
To put this into perspective, 120 watts of wired charging takes 17 minutes to charge a dead phone to 100% while wireless charging would take about 3 hours which is nine times slower. When it comes to efficiency, wireless charging tends to take a toll. According to the law of conservation of energy, it can neither be destroyed nor created but it can be transformed from one form to another.
Since, energy has to travel from the transmitter to the wireless charger’s material to the phone’s case then to the coil, energy tends to get wasted. What I mean by wasted is that not all energy is received as electrical, some of it is transformed to heat energy which poses great danger to the battery.
Air charging.
Companies are now pushing the boundaries of charging. Recently Xiaomi came out with their prototype air charging device which relies on what they refer to as Xiaomi Mi Air Charge Technology.
They are not the first ones but they are the ones who are doing it much better than most of the competition. The Xiaomi prototype charger is capable of emitting 5 watts of power through the air.
How does it work.
Xiaomi’s Air charging technology works by use of a charging pile which has five phase interference antennas which are used to accurately determine the position of your mobile phone. The whole of this concept relies space positioning and energy transmission.
The charging pile is set at a standard place in a room and the role of the antennas is to accurately determine the position of your smartphone in order to deliver power.
Now that the phone’s location has been determined, the next step is now delivering the power. For power delivery, the charging pile relies on a phase control array which consists of 144 antennas that transmit millimeter waves to the phone through beamforming. Beamforming is simply sending a wireless signal to a specified device.
On the smartphone, Xiaomi has designed a small array of antennas which comprises of a beacon antenna and a receiver antenna. The main purpose of the beacon antenna is to broadcast the exact location of the mobile phone to the charging pile while consuming low power. The receiving antenna array has 14 antennas which convert the millimeter waves emitted by the charging pile into an electric current through the rectifier circuit. 5 watts to be exact, is the amount of power that your mobile phone will be receiving.
Concerns about Air charging.
1. Obstacles.
When Xiaomi announced this technology, one of the questions that bamboozled people is whether obstacles between the charging pile and the mobile phone can cause an interference in power deliver. The answer is no. Although it is still unclear, Xiaomi claims that obstacles do not affect the efficiency of power delivery.
2. Health concerns.
Anything that radiates energy always poses a health concern. But with this type of air charging, there should be no health concerns. This is because the millimeter waves emitted by the charging pile are not ionizing. This means unlike stronger electromagnetic wave (X-rays and Gamma rays), millimeter waves do not have sufficient energy to cause ionization of electrons hence it is considered safer. It is also worth noting that these millimeter waves are the ones being used to transmit 5G signals.
Final thoughts.
Air charging is still in development and although some companies are actually producing them to the consumer market, are they worth the money. Of course not. Unless you are a tech enthusiast or you have some cash to spare, this technology is not yet ready and still needs some time for it to be fully developed.
It is still unclear when Xiaomi will actually release their Air charging technology to consumers since the one displayed earlier this year was a prototype. If the Xiaomi Air charger was available to the consumer market, would you consider buying it?
