High sensitivity flexible piezoresistive sensor of PDMS porous elastomer decorated by MXene-PEDOT:PSS

Flexible piezoresistive sensors have great application demands in wearable devices, electronic skins, man-computer interaction, and other fields. The common conductive sensitive media of flexible piezoresistive sensors suffer from high cost and complex preparation processes, which limit their practical application and mass production. A porous polydimethylsiloxane (PDMS) elastomer was prepared using gelatin as a sacrificial agent, and a MXene-poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT:PSS)/PDMS composite piezoresistive sensor was obtained by impregnation method. Experimental results demonstrated that when the composite concentrations of PEDOT:PSS and MXene are 15 mg/mL and 10 mg/mL, respectively, the sensor has the highest sensitivity, reaching up to 29.1 kPa⁻¹ under the force range of 12-40 kPa. The response and recovery time of the piezoresistive sensor are 0.36 s and 0.6 s, respectively. After verification, the sensor can detect the movement of human joints (finger, elbow and knee), indicating that the developed piezoresistive sensor exhibits good application prospects in the fields of smart clothing, flexible wearable electronic devices, and human-computer interaction.