MXene/air-laid paper composite sensors for both tensile and torsional deformations detection

Two-dimensional Ti₃C₂T_x MXene nanosheets with excellent electrical conductivities have been synthesized in this work. The nanosheet is further assembled with air-laid paper and polydimethylsiloxane substrate, for sensing both tensile and torsional deformations. Results show that the sensor is able to detect a linear stretchability of up to 90% with the corresponding gauge factor of 1–2.58. After repeated stretching and releasing cycles at a strain of 10% for 2000 cycles, the remaining change of relative resistance is only 0.1. Particularly, the sensor also displays responsive electrical signal change when torqued from 0 to 2π radian, suggesting a potential application for torsion deformation detecting. For demonstration, the sensor is applied in real-time monitoring the physiological movements, revealing outstanding capability of recognizing motions of finger bending, squat/rise, speaking and twisting.