A Temperature-Controlled, Conductive PANI@CNFs/MEO2 MA/PEGMA Hydrogel for Flexible Temperature Sensors.

Electrically conductive, yet stimuli-responsive hydrogels are highly desirable for many technological applications. However, the discontinuous conductivity of hydrogels during the response process has become a bottleneck that limits their application. To overcome this constraint, a linearly tunable, electrically conductive hydrogel is prepared using in-situ polymerized polyaniline (PANI) on a CNFs/MEO2 MA/PEGMA hydrogel (PANI@CMP hydrogel) substrate. The PANI@CMP hydrogel exhibits temperature-tunable electrical conductivity due to the liner relationship between thermosensitivity and temperature of the CMP hydrogel substrate. Furthermore, the stiffness and elasticity of the resultant hydrogel after PANI introduction is enhanced via physical interactions, and the compression load is improved by 42%. A highly sensitive temperature sensor is therefore fabricated with PANI@CMP hydrogel as the flexible induction element, and this sensor achieves temperature monitoring from 20 to 60 °C. This new temperature-controllable conductive hydrogel has excellent mechanical properties, showing great potential for applications in flexible smart sensors, conductive fillers, and medical devices.