A stretchable, self-healing, okra polysaccharide-based hydrogel for fast-response and ultra-sensitive strain sensors

Self-healing conductive hydrogels have attracted widespread attention as a new generation of smart wearable devices and human motion monitoring sensors. To improve the biocompatibility and degradability of such strain sensors, we report a sensor with a sandwich structure based on a biomucopolysaccharide hydrogel. The sensor was constructed with a stretchable self-healing hydrogel composed of polyvinyl alcohol (PVA), okra polysaccharide (OP), borax, and a conductive layer of silver nanowires. The obtained OP/PVA/borax hydrogel exhibited excellent stretchability (~1073.7%) and self-healing ability (93.6% within 5 min), and the resultant hydrogel-based strain sensor demonstrated high sensitivity (gauge factor = 6.34), short response time (~20 ms), and good working stability. This study provides innovative ideas for the development of biopolysaccharide hydrogels for applications in the field of sensors.