A self‐healing electrostatic interaction crosslinked temperature sensitive conductive hydrogel for strain and temperature sensor

Abstract A multifunctional hydrogel (C‐ASI‐G) was prepared through a simple acid–base neutralization method. Due to the large number of electrostatic cross‐linked network in the hydrogel and the reversible network, the hydrogel showed good mechanical properties (stress is 495 kPa, strain is 772%) and excellent self‐healing performance (self‐healing efficiency is over 95%). In addition, by adding glycerin to the dispersion medium, hydrogel retain water for a long time and remain flexible at low temperature. The hydrogel contains an ionizable polymer electrolyte, sodium polystyrene sulfonate, so it has outstanding electrical conductivity (0.36 s/m). The hydrogel can be used in general strain sensing and temperature sensing, its conductivity changes with temperature. The temperature and conductivity of the hydrogel were simulated as function, the environmental temperature of the hydrogel could be calculated by the conductivity of the hydrogel, and the error was less than 0.45°C. Because hydrogel can sense stress and temperature stimuli through the change of electrical signals, it will exhibit broad application prospect in the field of bionic intelligent robots.