Highly conductive and stable double network carrageenan organohydrogels for advanced strain sensing and signal recognition arrays

Abstract

Conductive hydrogels with excellent mechanical properties, a broad detection range, and stability in complex environments have remained a significant challenge for the development of flexible sensors. In this study, a straightforward freeze-thaw cycles strategy was developed to fabricate a polyvinyl alcohol (PVA)/carrageenan (CA)/calcium chloride (CaCl2)/MXene-based double network organohydrogel (PCCME) for highly flexible and responsive strain detection across a broad temperature spectrum. The PCCME organohydrogel features multiple interactive forces including hydrogen bonding, ionic interactions, and microphase crystallization, which contribute to the organohydrogel's exceptional mechanical and electrical performance. The PCCME organohydrogel exhibited excellent performance in a load-unload test repeated 100 times after being maintained at room temperature for 7 days, with a minimal mechanical decay of only 2.6%. Furthermore, the repaired PCCME organohydrogel retained its robust stability after storage at low temperatures followed by placement at room temperature. The organohydrogel sensor not only detects various movement amplitudes of the human body but also recognizes arrays of pressure signals and converts these into digital images, highlighting its significant potential for applications in rehabilitation monitoring, pressure sensing, and human-computer interaction.