Multifunctional Piezoresistive Sensor Utilizing MXene/CNC/WPU Aerogel for Efficient Motion Detection and Thermal Insulation

Piezoresistive sensors hold promising prospects in various fields such as health monitoring, human–computer interaction, and robot sensing. To meet diverse application requirements, the development of multifunctional piezoresistive sensors possessing high sensitivity, mechanical robustness, and thermal insulation properties is imperative. In this study, we report the fabrication of a high-performance MXene-based aerogel, denoted as MXene/CNC/WPU, via unidirectional freeze-casting of cellulose nanocrystals, waterborne polyurethane, and Ti3C2Tx MXene, facilitated by hydrogen bonding. The resulting three-dimensional interconnected layered microstructure imparts the MXene/CNC/WPU aerogel-based piezoresistive sensor with remarkable features including high piezoresistive linear sensitivity (224.42 kPa–1), exceptional mechanical stability (up to 500 compressing cycles), and rapid response time (0.15 s), along with the ability to withstand compression strains of up to 80% (corresponding to 42 kPa). Furthermore, the piezoresistive sensor demonstrates real-time detection capabilities for various human physiological signals such as swallowing, blowing, finger and wrist bending. Moreover, the MXene/CNC/WPU aerogel, with a thickness of 1.5 cm, exhibits outstanding thermal insulation performance, generating a temperature gradient of approximately 150 °C at 210 °C. These remarkable attributes underscore its potential applications in health monitoring and high-temperature protection.