Flexible MXene/PDMS/SWCNT nanocomposites for high-performance resistive strain sensors with potential application in low temperature

This paper proposes a novel method for preparing a flexible strain sensor based on a PDMS (Polydimethylsiloxane)/MXene/Single-walled carbon nanotube (SWCNT) nanocomposite. MXene (Ti3C2Tx) was synthesized using a modified MILD method from the MAX phase, which demonstrated improved exfoliation compared to the other method. The polymer nanocomposite was fabricated using the solvent casting technique. The effective intercalation of SWCNTs within MXene layers significantly enhances the electrical conductivity of the nanocomposite. The flexible strain sensor was successfully fabricated and exhibited a wide strain detection range exceeding 50%. The flexible strain sensor was evaluated through multiple tests, including a 60-minutes stretch and release cycle, torsion tests, finger bending, and wrist motion detection, demonstrating its potential application in human motion monitoring. Strain sensing performances, including stretchability, linearity, and durability, were comprehensively evaluated, and compared for PDMS/SWCNT and PDMS/MXene/SWCNT film. In addition, differential scanning calorimetry (DSC) tests were performed to evaluate thermal properties.