Antibacterial and UV-Blocking Bioelectronics Based on Transparent, Adhesive, and Strain-Sensitive Multifunctional Hydrogel

Skin-attachable conductive hydrogels are ideal candidates for the design of flexible and wearable electronics, and tremendous efforts are devoted to preparing multifunctional hydrogels. However, antibacterial ability and ultraviolet (UV)-blocking property are still essential yet rarely reported. In this study, a novel ionically conductive multifunctional polyacrylamide (PAAm)/chitosan (CS)/tannic acid (TA) hydrogel (PCT hydrogel) with transparency, adhesiveness, antibacterial activity, and UV-blocking ability simultaneously is fabricated via a facile one-pot strategy. In the hydrogel, PAAm chains form the backbone of PCT hydrogel, CS and TA endow hydrogel with antibacterial activity (>97%) and UV-blocking ability (>96%), respectively. More importantly, existing free ions also endue PCT hydrogel with conductivity (0.256 ± 0.005 S m −1 ) and strain sensitivity (GF > 3). The prepared PCT hydrogel-based strain sensors can effectively monitor various human movements, indicating their huge potential in soft robotics, human–machine interaction, and health-monitoring systems.