Ultrasound-driven triboelectric and piezoelectric nanogenerators in biomedical application

Microelectronics play a crucial role in medical settings by monitoring physiological signals, treating illnesses, and enhancing human well-being. For implanted and wearable devices, a reliable and continuous energy source is essential. While conventional energy systems rely on batteries and external power connections, their drawbacks, including the need for frequent charging, limited battery lifespan, and the potential for reoperation, restrict their utility. This has spurred the exploration of self-sustaining, long-lasting power solutions. The ultrasound-driven nanogenerator, a promising energy source, harnesses biomechanical energy from activities like muscle movement, heartbeat, respiration, and gastric peristalsis. It converts this energy into electrical signals, enabling the detection of physiological and pathological markers, cardiac pacing, nerve stimulation, tissue repair, and weight management. In this review, we provide an overview of triboelectric (TENG) and piezoelectric (PENG) nanogenerator design with ultrasound and its applications in biomedicine, offering insights for the advancement of self-powered medical devices in the future. These devices hold potential for diverse applications, including wound treatment, nerve stimulation and regeneration, as well as charging batteries in implanted devices.