A self-healing, stretchable, and conductive Poly(N-vinylpyrrolidone)/gallic acid composite hydrogel formed via hydrogen bonding for wearable electronic sensors

Hydrogels have emerged as fascinating material for various applications in the chemical, biomedical, and energy fields. Generally, their poor self-healing performance, mechanical properties, and bioactivity limit the application of hydrogels in bioelectronics. Herein, a self-healable, injectable, stretchable, self-adhesive, biocompatible, and conductive poly(N-vinylpyrrolidone)/gallic acid (PVP/GA) composite hydrogel was fabricated via hydrogen bonding between the tertiary amide groups in PVP and hydroxyl groups in GA. The PVP/GA composite hydrogel possesses excellent self-healing properties after damage. The composite hydrogel is highly stretchable and can adhere to human skin to detect physiological activity signals precisely according to the resistance signals. The composite hydrogel has good biocompatibility with living organisms. It is envisioned that multifunctional PVP/GA composite hydrogels can be applied to the electronic skins, wearable biosensors, and body movements monitoring equipment.