Highly stretchable, self-healing, and degradable ionic conductive cellulose hydrogel for human motion monitoring

Self-healing biomass-based conductive hydrogels are applied as flexible strain sensors for wearable devices and human movement monitoring. Cellulose is the most abundant biomass-based materials and exhibits excellent toughness, dispersion and degradability. In this paper, nanocellulose crystals (NCCs) prepared from sisal, used as reinforcing fillers were coated with tannic acid (TA) to prepare inexpensive bio-nanocomposite hydrogels that also included polyvinyl alcohol, okra polysaccharide (OP), and borax. These hydrogels exhibit excellent selfhealing and mechanical properties with the maximum elongation, toughness, and self-healing efficiency (9 min) of 1426.2 %, 264.4 kJ/m3, and 62.1 %, respectively. A fabricated hydrogel strain sensor was successfully used to detect and monitor various human movements such as wrist bending, elbow bending, and slight changes in facial expression. In addition, this sensor possessed excellent durability and good working stability after repeated circulation. The nanocomposite hydrogel synthesized in this work utilized natural polysaccharide to manufacture flexible functional materials with good application prospects in the field of flexible sensors.

Automated summary

In this study, self-healing biomass-based conductive hydrogels were developed for wearable devices and human movement monitoring. The hydrogels exhibited excellent mechanical properties and self-healing efficiency. A strain sensor fabricated from the hydrogels successfully detected and monitored various human movements. The sensor also showed good durability and working stability.