Researchers at Korea Advanced Institute of Science and Technology (KAIST) claim to have developed a wireless-power transfer (WPT) system that allows mobile devices to be charged at any location and in any direction, even if the devices are away from the power source, just as Wi-Fi works for Internet connections.
Team leader, Professor Chun Rim of the Nuclear and Quantum Engineering Department at KAIST, said his team used high-frequency magnetic materials in a dipole coil resonance system (DCRS) to build a thin, flat transmitter system shaped in a rectangle with a footprint of 1m2. It is also claimed that either 30 smartphones with a power capacity of 1W each or five laptops with 2.4W each can be simultaneously and wirelessly charged at any point within a 50cm distance from the transmitter.
The maximum power transfer efficiency for the laptops is said to be 34%.
The DCRS works in a low magnetic field environment. Using shielding technology developed by the research team, the magnetic flux level of 27µT is less than international safety levels.
Professor Rim said, "Our transmitter system is safe for humans and compatible with other electronic devices. We have solved three major issues of short charging distance, the dependence on charging directions, and plane coil structures of both Tx and Rx, which have blocked the commercialisation of WPT."
The research team and KAIST's spin-off company, TESLAS, have been conducting pilot projects to apply DCRS in various places such as cafes and offices.
Author
Tom Austin-Morgan
Source: www.newelectronics.co.uk