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.