Anchor: A new technology developed by KAIST aims to allow users to wirelessly charge their smartphones, similar to using the Internet in a wifi zone. Using the first of its kind technology users can freely move about and use their phones within 50 centimeters of the charging device.
Our Kim In-kyung has more.
 
Report: Until now, smartphone users had to leave their devices in the close vicinity of a charger even when charging wirelessly. 
 
The slightest movement would hinder the wireless charging and it was difficult to use the phone while it was being charged. 
 
Non-contact wireless charging technology, which has been in the development process, had its limits as it required a connection within a ten-centimeter radius.
 
Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have come up with a stronger alternative.
 
The researchers, led by Professor Rim Chun-taek, announced the new method on Tuesday, which allows users to freely move about and charge their mobile devices within 50 centimeters, or almost 20 inches, of the charger. 
 
The technology involves a rotating magnetic field, generated from a cross-shaped coil in the charger, which is transmitted wirelessly to a receptor coil in the smartphone.
 
Professor Rim of the university's nuclear and quantum engineering department said the new technology allows smartphones to be charged in any position or direction.
 
The power transmission efficiency of the technology is currently at 34 percent. This means a one-square-meter wireless charging pad may simultaneously charge 30 smartphones in ten hours.
 
The research team has also successfully reduced the magnetic field strength from the charger to below international safety standards to prevent harm to a human body.
 
Choi Bo-hwan, a graduate student at KAIST, said the charger has been designed in a way that the magnetic field reaching the side of the phone facing a person is five times lower than the opposite side.
 
The research team plans to commercialize the technology to allow users to wirelessly charge their smartphones in places such as coffee shops and offices.
Kim In-kyung, KBS World Radio News.