Ambient charging tested
Researchers are working on a new system that could see an entire room turned into a charger for devices located within it.
Many phones and other new devices offer wireless charging technology in which they are placed on a charging mat rather than using a cable.
International researchers have now developed a way to install conductive surfaces into walls to create magnetic field patterns throughout a room a small electronic device can pick up to charge even while still in use.
Better still, the researchers say these charging currents are safe to be around, with tests showing they meet Institute of Electrical and Electronics Engineers safety guidelines.
Dr Takuya Sasatani from the University of Tokyo and colleagues have developed a method of turning a room into a wireless power transfer system that uses multidirectional, distributed currents on conductive surfaces that are built into the walls.
The technique - dubbed ‘multimode quasistatic cavity resonance’ - generates three-dimensional magnetic field patterns throughout the entire room (3 m × 3 m × 2 m) that can efficiently couple to small coil receivers attached to electrical devices such as smartphones, lightbulbs and fans.
The coil receivers need to be aligned at right angles to the magnetic field to achieve maximum efficiency, however, power delivery efficiency exceeding 37.1 per cent is still achievable anywhere in the room and also while a device is in motion.
The authors suggest that this method provides greater flexibility over previous approaches, for example existing coil-based transmitters.
The authors expect that a safe demonstration of room-scale wireless power transfer could have wide-ranging applications in the provision of power to electronic devices used in both industrial and personal living spaces.