Aesthetic, wire-free and bioresorbable dermal tattoo TENG system for self-powered on-the-go biomedical applications

Triboelectric nanogenerators (TENGs) are promising for self-powered biomedical applications such as wound healing, cancer therapy, and biosensing. However, their dependence on external wires and electrodes limits usability and comfort. Here, we introduce a wire-free approach using dermal conductive tattoos. Unlike conventional systems requiring a back conductor, our method uses skin as the triboelectric layer, with charge transferred via subdermal conductive tattoos—eliminating external accessories. This concept was validated through triboelectric testing of skin, tattoo performance on artificial models, bioresorbable ink development, and in vivo voltage generation. The system successfully accelerated wound healing in freely walking animals, powered solely by body motion. The use of bioresorbable zinc-based inks enabled temporary functionality that disappeared naturally with the healing process. Furthermore, the tattooed electrodes can be seamlessly merged with artistic designs, paving the way for next-generation bioelectronic tattoos that are both therapeutic and aesthetically personalized.