Ti3C2-MXene ionogel with long-term stability and high sensitivity for wearable piezoresistive sensors

Abstract

Wearable piezoresistive sensors have attracted tremendous attention recently, which can be applied for health monitoring and human-computer interaction. MXenes, possessing high metallic conductivity and large specific surface area, are often used as the conductive filler in hydrogels and organohydrogels for piezoresistive sensors. However, the environmental instability of MXene composites caused by the easy oxidation of MXene is a long-standing issue which needs to be solved urgently. Herein, taking advantage of phase transfer achieved by cationic surface active ionic liquid 1-vinyl-3-dodecylimidazolium bromide ([VC12Im]Br), we combine Ti3C2Tx with hydrophobic ionic liquid to fabricate Ti3C2-MXene ionogel successfully, which exhibits high compressibility (2.97 MPa), high conductivity (0.908 mS/cm) and long-term stability (40 days). And the wearable piezoresistive sensor based on Ti3C2-MXene ionogel shows rapid response time (100 ms), high sensitivity (6.47 kPa−1) and wide detection range, thus can be used to monitor the tiny movements of human body parts, recognize vocalizations and handwriting. This preparation method develops a new path to fabricate Ti3C2-MXene ionogel with long-term stability and high sensitivity for wearable electronic devices.