3D MXene-Based Flexible Network for High-Performance Pressure Sensor with a Wide Temperature Range

With the increasing popularity of smart wearable devices, flexible pressure sensors are highly desired in various complex application scenarios. A great challenge for existing flexible pressure sensors is to maintain high sensitivity over a wide temperature range, which is critical for their applications in harsh environments. Herein, a flexible piezoresistive sensor made of polyetherimide (PEI) fibrous network evenly covered with MXene nanosheets is reported to construct conductive pathways, showing ultrahigh sensitivity over a wide temperature range from -5 degrees C (sensitivity of 80 kPa(-1)) to 150 degrees C (20 kPa(-1)), low detection limit of 9 Pa, fast response time of 163 ms, outstanding durability over 10 000 cycles at room temperature, 2000 cycles at 100 degrees C and 500 cycles at -5 degrees C. The pressure sensor can monitor various human activities in real-time, apply to human-machine interaction, and measure pressure distribution. It also can sensitively respond to external mechanical stimuli at 150 degrees C and extremely low temperature (in liquid nitrogen). Moreover, the fibrous network exhibits an excellent Joule heating performance, which can reach 78 degrees C at an applied voltage of 12 V. Thus, the piezoresistive sensor has considerable potential for wearable garments and personal heating applications in harsh temperature conditions.