Recent Advances in Chitosan-Based Hydrogels for Flexible Wearable Sensors

Flexible wearable sensors show great potential for applications in wearable devices, remote health monitoring, artificial intelligence, soft robotics, and artificial skin due to their stretchability, bendability, thinness and portability, and excellent electrical properties. Hydrogels have tunable mechanical properties, excellent biocompatibility, and flexibility, making them attractive candidates for wearable flexible sensors. Among them, tremendous efforts have focused on the advancement of chitosan-based hydrogels (CS-Gels) to realize multifunctional wearable sensing by modifying hydrogel networks with additives/nanofillers/functional groups. Recently, remarkable progress has been made in flexible wearable sensors. Herein, this review summarizes recent advances in CS-Gels wearable sensors for applications such as human motion monitoring, health monitoring, human-machine interface and soft robotics. Representative synthesis methods and strategies for CS-Gels are briefly described, the problems and deficiencies of CS-Gels for wearable sensors are discussed. Finally, the possible opportunities and challenges for the future development of CS-Gels flexible wearable devices are proposed.