Versatile sensing devices for self-driven designated therapy based on robust breathable composite films

Flexible wearable electronics were developed for applications such as electronic skins, human–machine interactions, healthcare monitoring, and anti-infection therapy. But conventional materials showed impermeability, single sensing ability, and no designated therapy, which hindered their applications. Thus it was still a great challenge to develop electronic devices with multifunctional sensing properties and self-driven anti-infection therapy. Herein, flexible and breathable on-skin electronic devices for multifunctional fabric based sensing and self-driven designated anti-infection therapy were prepared successfully with cellulose nanocrystals/iron(Ⅲ) ion/polyvinyl alcohol (CNC/Fe³⁺/PVA) composite. The resultant composite films possessed robust mechanical performances, outstanding conductivity, and distinguished breathability (3.03 kg/(m²·d)), which benefited from the multiple interactions of weak hydrogen bonds and Fe³⁺ chelation and synergistic effects among CNC, polyaniline (PANI), and PVA. Surprisingly, the film could be assembled as a multifunctional sensor to actively monitor real-time physical and infection related signals such as temperature, moisture, pH, NH₃, and human movements even at sweat states. More importantly, this multifunctional device could act as a self-driven therapist to eliminate bacterial by the release of Fe³⁺, which was driven by the damage of metal coordination Fe–O bonds due to the high temperature caused by infection at wound sites. Thus, the composite films had potential versatile applications in electronic skins, smart wound dressings, human–machine interactions, and self-driven anti-infection therapy.