Korean research team successfully uses ultrasonic waves to charge electronic devices remotely

Korean researchers have successfully developed wireless charging technology through ultrasonic waves, which can be applied to charging pacemakers or chips that automatically push drugs into the body. Thanks to ultrasonic charging technology, patients will no longer need to frequently remove the device from their body.

Illustration of the research team from KIST.

New wireless charging technology is being applied in powering smartphones, smartwatches, etc. due to its low performance and short charging distance.

Normally, a layer of copper creates an electromagnetic field, transferring energy to an inductive coil contained in a device that is capable of turning an electromagnetic field into an electric current. However, this wireless charging technology requires the two devices to be in contact.

A representative of the Korea Institute of Science and Technology (KIST) said that the research team had chosen ultrasonic waves instead of electromagnetic waves as the energy transfer system. The team has specifically designed a triboelectric device that can transmit ultrasonic waves, to convert energy into electricity.

In underwater testing, the KIST team was able to transfer 8 megawatt-hours of energy into a device located 6 centimeters from the power source. The device efficiency reaches 4%, enough to light about 200 LEDs or power the sensor to transmit data via bluetooth.

KIST experts say that the energy conversion efficiency is very high, when the charging system does not generate too much heat during the test. In addition, wireless charging technology can find "martial ground" in charging medical devices attached to the body. Ultrasound has also been familiar to the medical profession for hundreds of years, from performing organoscopy to observing the developing fetus.

"[Testing] has shown that the wearable device can operate with electricity provided by the new charging technology," researcher Song Hyun-cheol said at a press conference. The professor said that when the performance and safety are improved, the charging technique can be applied in medicine and also in sensors to explore the seabed.