A local research team has succeeded in developing a technology that can charge a battery of an in-body medical device with ultrasonic waves.
Until now, patients who had in-body medical devices, such as artificial heart pacemakers, nerve stimulators, and insulin pumps, needed to undergo further surgery to replace the power-consuming devices. The method was not desirable as it cost more money for the patients, while the operation caused additional pain.
To solve such problems, researches have been actively carrying out studies to convert various kinds of mechanical energy generated in the body to electric energy.
However, the magnetic induction and resonance systems, which are conventional wireless power systems, had technical limitations such as large size, malfunction due to electromagnetic interference, and the need for a shielding agent to cover the metal packaging.
The team, led by Professor Kim Sang-woo at Sungkyunkwan University, developed an energy harvesting technique that constantly charges the implantable medical device with the tritium produced in the body without periodic procedures for battery replacement.
The researchers found hints in ultrasound used for physical examination and treatment.
“External ultrasound brings about the deformation of a specific material inserted into the body,” the team said. “We proved that triboelectricity induced by vibration due to deformation could be used to generate a high level of electrical energy.”
In this study, the team used ultrasonic waves, which can transmit into a living body, as an external mechanical energy source to increase the output current more than 1,000 times.
The researchers confirmed that when inserting the triboelectric element into the skin of a rat or pig, the triboelectricity induced by the ultrasonic waves from the outside can harvest energy.
They obtained a power output of 0.91 V, 52.5 μA from a power device inserted at a depth of 1 cm from the fat layer of the pig, which is enough to power an artificial heart pacemaker or a nerve stimulator.
“We could present a new concept of energy harvesting in the body using ultrasonic triboelectricity through the skin layer,” Professor Kim said. “And we expect the result of the research will present a new milestone in the in-body medical-device industry.”
The journal Science published the research.