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

Abstract 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.