Self-Healable, Antimicrobial and Conductive Hydrogels Based on Dynamic Covalent Bonding with Silver Nanoparticles for Flexible Sensor

Dynamic hydrogels have attracted considerable attention in the application of flexible electronics, as they possess injectable and self-healing abilities. However, it is still a challenge to combine high conductivity and antibacterial properties into dynamic hydrogels. In this work, we fabricated a type of dynamic hydrogel based on acylhydrazone bonds between thermo-responsive copolymer and silver nanoparticles (AgNPs) functionalized with hydrazide groups. The hybrid hydrogels exhibited sol-gel transition, self-healable, injectable and thermo-responsive abilities. The self-healing efficiency was over 92%. Moreover, the hydrogel displayed antimicrobial properties and high conductivity (6.85 S/m). Notably, the fabricated hydrogel-based sensors exhibited strain and temperature sensing (22.05%/°C) and could detect human motion and speech, and electrocardiographic (ECG) and electromyography (EMG) signals. Overall, this work provides a simple strategy to synthesize AgNPs-based dynamic hydrogels with multi-functions, and the hydrogels may find potential applications in antibacterial wearable electronics, health monitoring and speech recognition.