Nanocellulose-templated carbon nanotube enhanced conductive organohydrogel for highly-sensitive strain and temperature sensors

Conductive hydrogels have garnered wide interest for various promising applications, such as wearable devices, electronic skins, and intelligent robots. However, these hydrogels still suffer from weak mechanical properties, poor environmental stability, and low sensitivity. Here, we report a conductive organohydrogel that is easily synthesized by a one-step acrylamide polymerization in the presence of cellulose nanofiber (CNF)-templated carbon nanotube (CNT) hybrids and glycerol-water binary solvent. The uniformly dispersed CNF/CNT nanohybrids act as a reinforced and conductive skeleton, which synergistically endows the organohydrogel with excellent tensile strength (≈ 119.2 kPa) and high electronic conductivity (≈ 2.7 mS cm−1). Moreover, the synergy of glycerol-water solvent network and polyacrylamide (PAAm) polymer matrix provides an ultra-stretchability (up to 1343%) and skin-like modulus (≈ 17.7 kPa), which can well match the dynamic human–machine interface. Furthermore, the organohydrogels exhibit excellent flexibility under an extreme temperature (< − 24 °C) and maintain the long-term water-retention capability in an open environment (> 10 days), owing to the glycerol-enhanced H-bonding interface interactions. Benefiting from these high performances, our organohydrogel can be employed for preparing multifunctional sensing devices, which display high sensitivity to external strains (gauge factor = 10.03) and dynamic temperature changes (temperature coefficient of resistance = − 1.081% °C−1), superior to the most reported samples. Our results pave the way for simple and practical systems that fulfill the requirements of intelligent electronic devices.Graphical abstract