Ultrasound‐Driven Injectable and Fully Biodegradable Triboelectric Nanogenerators

Abstract Implantable medical devices (IMDs) provide practical approaches to monitor physiological parameters, diagnose diseases, and aid treatment. However, device installation, maintenance, and long‐term implantation increase the risk of infection with conventional IMDs. Therefore, medical devices with biocompatibility, controllability, and miniaturization are highly demandable. An ultrasound‐driven, biodegradable, and injectable triboelectric nanogenerator (I‐TENG) is demonstrated to reduce the risks of implant‐related injuries and infections. The injection can be given by subcutaneous injection with a needle to minimize the implantation incision. The stable output of I‐TENG is driven by ultrasound (20 kHz, 1 W cm −2 ), with a voltage of 356.8 mV and current of 1.02 µA during in vivo studies and an electric field of about 0.92 V mm −1 during ex vivo experiments. The cell scratch and proliferation assays showed that the delivered electric field effectively increased cell migration and proliferation, indicating a significant potential to accelerate healing with electricity.