Wearable Sensor Based on a Tough Conductive Gel for Real-Time and Remote Human Motion Monitoring

The
usage of a conductive hydrogel in wearable sensors has been
thoroughly researched recently. Nonetheless, hydrogel-based sensors
cannot simultaneously have excellent mechanical property, high sensitivity,
comfortable wearability, and rapid self-healing performance, which
result in poor durability and reusability. Herein, a robust conductive
hydrogel derived from one-pot polymerization and subsequent solvent
replacement is developed as a wearable sensor. Owing to the reversible
hydrogen bonds cross-linked between polymer chains and clay nanosheets,
the resulting conductive hydrogel-based sensor exhibits outstanding
flexibility, self-repairing, and fatigue resistance performances.
The embedding of graphene oxide nanosheets offers an enhanced hydrogel
network and easy release of wearable sensor from the target position
through remote irradiation, while Li+ ions incorporated
by solvent replacement endow the wearable sensor with low detection
limit (sensing strain: 1%), high conductivity (4.3 S m–1) and sensitivity (gauge factor: 3.04), good freezing resistance,
and water retention. Therefore, the fabricated wearable sensor is
suitable to monitor small and large human motions on the site and
remotely under subzero (−54 °C) or room temperature, indicating
lots of promising applications in human-motion monitoring, information
encryption and identification, and electronic skins.