Researchers Charge Batteries via Ultrasonics, Aim to Make Implantable Electronics Less Invasive
New flexible, high-efficiency nanogenerators turn ultrasonic vibrations into enough energy to keep implantable devices running.
Researchers from the Korea Institute of Science and Technology (KIST), Korea University, Sungkyunkwan University, Yonsei University, and the University of California have come up with a new approach to efficiently charge batteries in implantable devices using ultrasonic signals — by boosting the capabilities of triboelectric nanogenerators (TENGs).
"Through this research, we have demonstrated that wireless power transmission technology using ultrasound can be applied practically," says co-corresponding author Sunghoon Hur of the team's work. "We plan to conduct further research for miniaturization and commercialization to accelerate the practical application of the technology."
That technology: a means to recharge the batteries of implanted medical devices using harmless ultrasound. The trick is the use of ultrasound-driven triboelectric nanogenerators (US-TENGs), tiny devices that turn vibrations — in this case from an ultrasound probe applied to the body — into electricity. The only problem: previous implementations have lacked the power to be practical, which is where the team's work comes in.
The dielectric-ferroelectric boosted US-TENG developed by the team uses a stretchable and biocompatible design, making it better suited to use in implants, and retains its performance even when bent. That performance, too, outpaces the competition: in testing the prototypes were able to generate around 26VDC at 6.7mW at a 35mm (around 1.4") distance though skin — rising to 20mw at the same distance underwater, leading the team to consider the same approach for powering underwater drones and sensor systems.
The increased flexibility of the team's US-TENG suggests another application, too: the researchers say that it could be used to provide a means of charging larger and more complex implantable devices — all the way up to complete artificial hearts.
The team's work has been published in the journal Advanced Materials under open-access terms.