A new technology has been developed that allows smartphones to be charged wirelessly over a distance of up to 30 meters. The system uses an infrared laser with a wavelength of 1,550 nanometers, which is safe for humans even if it hits the eye. Inductive charging systems have been available for several years, but until now, the device had to be positioned on or near the charging station. The new technology, developed by scientists at Sejong University, allows devices with a receiving module to be charged wirelessly over longer distances, as long as there is a direct line of sight between the receiver and the infrared laser beam.
The system automatically switches to a safe energy transfer mode if the line of sight between the sender and receiver is interrupted. In experiments, the new technology was able to transmit power wirelessly over a distance of 30 meters. The system has the potential to power a range of devices wirelessly, including smartphones, tablets, and sensors used in manufacturing processes. The researchers used an erbium-doped fiber amplifier to emit the infrared beam, which is received by a retroreflector with an integrated photovoltaic cell that converts the light back into electricity.
The system currently delivers a power output of 85 milliwatts to the device being charged, which is sufficient for simple sensors but slow for charging smartphones. The researchers are working on improving the system’s performance, including developing a photovoltaic cell with a higher efficiency and adapting the system to power multiple devices simultaneously. The technology could have applications in industry, where it could be used to power sensors wirelessly, reducing maintenance and replacement costs in harsh environments where electrical connections can cause interference or pose a fire hazard.
