Hydrogels for Wearable Electronics

Hydrogels have tremendous flexibility, stretchability, and biocompatibility, making them ideal candidates to serve as the core materials of wearable electronics. In comparison with classical sensors, hydrogels can overcome limitations in elasticity and toughness. Particularly, nanocomposite hydrogels (NCHs)-based wearable electronics that could transfer external stimulus to electrical signals were immensely explored owing to their high sensitivity, considerable conductivity, and good mechanical strength. As typical flexible electronics, NCH sensors are in the classes of capacitive sensors and resistance sensors, which are mainly applied for real-time human motion monitoring. This chapter highlights NCHs and their utilization in the construction of wearable electronics in light of their properties, strain sensory performance, and potential applications. Lastly, a brief viewpoint for the future advances of stretchable and conductive NCHs engaged in wearable strain sensors will be provided.