The research team of Kim Sang-woo, a professor of Advanced Materials Science and Engineering at SKKU has developed original technology for wireless charging that can get over the limitations of implantable medical devices. Previously, implantable medical devices like cardiac pacemakers and insulin pumps needed the battery replaced regularly to supply power. There were several studies on converting mechanical energy in the body into electrical energy using heartbeat, blood flow, and muscle movement, but it was difficult to obtain enough power to charge the battery. Prof. Kim’s research team has found a safe way that generates sufficient electricity using harmless ultrasound which is used for physical examinations and treatment. The ultrasound emitted from outside the body causes vibrations on certain materials implanted in the body and generates frictional electricity. When it was tested on pig skin, the result showed that the output current increased more than 1,000 times compared to studies using a heartbeat. This study was published in the journal, Science, on August 2nd. “This study presented a new concept of energy harvesting using ultrasound-induced frictional electricity that passes through the skin layer. It is expected to suggest a new milestone for the human body implantable medical system industry,” Prof. Kim said.