Imagine charging your smartwatch without plugging it in. No cables, no charging pads—just invisible sound waves powering up your device. This isn’t science fiction anymore.
Scientists at the Korea Institute of Science and Technology (KIST) have created a way to charge devices using ultrasonic waves. These are sound waves we can’t hear, but they can carry energy through the air.
“We’ve been working to solve the limitations of current wireless charging,” says Dr. Min-Ho Bae, who led the research team. “Most wireless chargers today require devices to be very close together.”
Traditional wireless charging uses electromagnetic waves. These work well but can heat up metal objects nearby. They also lose power quickly over distance.
The KIST team took a different approach. Their system sends ultrasonic waves from a transmitter to your device. A special material in the receiver converts these sound waves into electricity.
What makes this breakthrough special is how efficiently it works. The team achieved 11.4% efficiency at a 30cm distance—about the length of a school ruler. This is much better than previous ultrasonic systems.
The technology is perfect for wearable devices. Imagine smartwatches, health monitors, or hearing aids charging while you wear them. No need to remove them at night.
Unlike other wireless charging methods, ultrasonic waves are safe around medical devices. They won’t interfere with pacemakers or other implants.
“The beauty of ultrasonic charging is its safety,” explains tech analyst Sarah Chen. “It doesn’t create electromagnetic interference that might affect sensitive equipment.”
This technology could transform how we use small electronics. Think of earbuds charging in their case, which itself charges from sound waves in your home.
The technology has limitations. It won’t charge your laptop or phone quickly. The power transfer is still relatively small—perfect for low-power devices but not energy-hungry ones.
KIST researchers are working to improve the system. They want to increase both the charging distance and power output.
“We’re just at the beginning of ultrasonic charging potential,” says Dr. Bae. “The efficiency will improve dramatically in the next few years.”
This advancement joins other emerging technologies like over-the-air charging using focused radio waves. Companies including Energous and Ossia are developing similar solutions.
What makes the KIST approach special is its safety and cost. The materials used are relatively inexpensive. The transmitters could be built into walls or furniture without major expense.
Looking ahead, this technology could help power the Internet of Things revolution. Billions of tiny sensors and devices need power but are often in hard-to-reach places.
“The biggest challenge for smart homes isn’t the technology—it’s keeping everything charged,” says home automation expert Miguel Santos. “Ultrasonic charging could solve this problem.”
As our world fills with more wearable and implantable technology, finding ways to power these devices safely becomes crucial. The days of removing your smartwatch to charge it might soon end.
This breakthrough reminds us that innovation often comes from exploring completely different approaches. Sometimes the answer isn’t making current methods better—it’s finding a new path altogether.
Will our future homes hum with invisible sound waves, keeping our devices powered day and night? KIST’s research suggests this silent charging revolution might be closer than we think.
Learn more about wireless charging and other technological innovations changing our daily lives.
