Acoustic Tunable Battery-Free Implants Based on Sustainable Triboelectric Nanogenerators With Metal-Polymer Intermixing Layers

Ultrasound-driven triboelectric nanogenerators (US-TENGs) offer an innovative solution for transcutaneous power transfer, with the potential to enable battery-free, permanently implantable electronics. However, research to date has primarily demonstrated only fragmentary functionalities for these applications. This work presents the simultaneous transmission of acoustic power and precise acoustic information using a double-electrode US-TENG, enabling a battery-free implant controlled via ultrasound. High and sustained output from a US-TENG is crucial for operating the versatile system; therefore, a novel triboelectric membrane with a top electrode incorporating a gold-polymer intermixing layer has been designed. Reversible micro-cracks form in the intermixing layer, ensuring electrical connectivity under high-frequency strain. In vivo experiments confirm that the system is biocompatible and can be reliably operated inside living rats. These achievements represent a significant step toward realizing multifunctional implantable electronics that can be reliably powered and controlled by ultrasound.