Environmentally stability, high-conductivity and wide-range eutectogel sensor reinforced by polyaniline-encapsulated carboxymethyl cellulose for multi-stimuli responsiveness

The hydrogels with high sensitivity on mechanical deformation, temperature and humidity have emerged as charming candidate materials for flexible sensor due to increasing development in flexible electronics and human-computer interaction fields. In this study, deep eutectic solvent gels (DESX) were firstly fabricated by dual-network compounding xanthan gum (XG) and polyacrylic acid (PAA), choline chloride (ChCl), and ethylene glycol (EG). Then sphere-shaped polyaniline encapsulated carboxymethyl cellulose (CMC-PANI) were incorporated as conductive and reinforcing supplement and the DESX/CMC-PANI eutectogel (DXCP) were successfully achieved via one-pot strategy with multi-stimuli responsiveness. The synergistic interaction of physical and chemical crosslinking of CMC-PANI, XG and PAA chains in DXCP eutectogels happens, and they display strong-stretchable mechanical properties, extreme environment stability, high frost resistance and water retention. Importantly, the superior DXCP-2 eutectogel especially exhibits 0.89 MPa of mechanical strength, 620% of stretchability, and 0.5 S/m of conductivity. Notably, the DXCP-2 was assembled into flexible sensors and these sensors exhibited good linear response and broad detection range toward strain, temperature and humidity. This approach offers effective gelation strategy for exploring multifunctional deep eutectogels with good cryogenic tolerance, high stretchability-strength, and non-irritating characteristics in flexible sensors detecting human motion, temperature and humidity.