New breakthrough: Charging through the air at a distance of nearly 30 meters

In the future, we may be able to charge phones and tablets at great distances in the air thanks to newly developed technology.

Researchers from Sejong University, South Korea have successfully used infrared laser light to transmit energy with a power of approximately 400mW at a distance of up to 30 meters.

In technical terms, this method is known as distributed laser charging. Compared with previous wireless transmission methods, the new research is emphasized by its ability to be safe and distance.

In the test setup, a specially treated amplifier generator called an erbium is placed 30 meters away from the receiver, with a sensor attached to convert the light signal into electrical energy.

The generated power is just enough to charge small sensors, and can progress to larger devices such as smartphones and tablets.

Experimental energy transmission through the air using a laser.

"Previous approaches mainly required the receiving device to be placed in a special charging base, or in a stationary state," explains Jinyong Ha, an electrical engineer at Sejong University in South Korea. "While the new method gives the user complete freedom, as long as the transmitter and receiver are within the necessary distance."

A plus point of this method is that the energy is transmitted absolutely safely. "With a central wavelength of 1550 nanometers, the laser is in the safest region of the infrared spectrum and cannot cause harm to human skin or eyes," the researcher said.

The laser emitter will even go into low power mode when no receiver is detected in "sight".

The research is said to have the potential to make a big difference, even in a manufacturing industrial environment, where cabling is difficult to deploy and maintain.