Conductive PNIPAM/CMCS/MWCNT/PANI hydrogel with temperature, pressure and pH sensitivity

Abstract In this work, a temperature‐sensitive conductive hybrid hydrogel is prepared by in situ polymerization on MWCNT reinforced PNIPAM/CMCS hydrogels. MWCNT and PANI combined the PNIPAM/CMCS matrix with physical and chemical crosslinking that improved the stiffness and elasticity of hydrogel. Due to good mechanical stretchability, high electrical conductivity, thermal responsiveness and pH sensitivity, this hydrogel has potential in the application of wearable devices, temperature sensitive sensor and pH detector. Polymer hydrogels with stimulus‐response characteristics with good electrical properties have great potential in electrical, electrochemical, and biomedical devices. Here, a temperature‐sensitive conductive hybrid hydrogel is prepared using in‐situ polymerized polyaniline (PANI) on PNIPAM/CMCS/MWCNT hydrogel substrate. The network of physical and chemical crosslinking endows the PNIPAM/CMCS/MWCNT/PANI hydrogel with highly porous structures, which greatly enhances the mechanical properties and enhances the stability. The hybrid hydrogel as a strain sensor shows high sensitivity (gauge factor 3.603) and outstanding linear dependence of sensitivity on strain. The hybrid hydrogels can be used to construct highly sensitive temperature alertor based on circuit disconnection caused by volume shrinkage at high temperatures. Moreover, the hybrid hydrogels can also be used as pH sensor to monitor changes of acid and alkali in the solution.