smartphones only works over a very short distance, requiring the user to put the device on the charger and align it correctly. Researchers from Sejong University in South Korea are proposing a new technology for which works this time on 30 meters. They published the details of their invention in the journal .
The current is sent by a transmitter, installed on the scale of a room, consisting of an amplifier with fiber doped with. It produces a ray of light with a central 1,550 . The receiver consists of a retroreflective spherical which concentrates the beam on a .
A system that charges devices from a distance of 30 meters
The device is small enough to be integrated into connected objects and even a smartphone. Themust be transmitted in a straight line, without obstacles. This is the reason for choosing the retroreflective spherical lens. It returns part of the ray which facilitates alignment and allows the transmitter to switch to a low intensity mode if an object blocks the transmission, thus becoming safe for human beings.
The researchers succeeded in transmitting a beam of 400 milliwatts over 30 meters, which was converted to 85 milliwatts on arrival, i.e.of 21.25%. This first prototype is only a proof of concept. The researchers plan to optimize the laser and increase the efficiency of the photovoltaic cell in order to be able to transmit more current over a longer distance. They also hope to adapt their device so that they can power several devices simultaneously.