Highly sensitive self-powered pressure and strain sensor based on crumpled MXene film for wireless human motion detection

Recently, pressure/strain sensor based on triboelectric nanogenerator (TENG) has gained great attentions for monitoring daily health status and robotic research fields, because of their simple device structures and self-powered feature. However, higher sensitivity and stretchability are still demanded for satisfying the practical applications. In this work, a self-powered pressure and strain sensor was achieved by utilizing crumpled MXene film as the single-electrode mode TENG. Benefiting from the reconfigurable behavior of the crumpled structure, the MXene TENG showed a maximum areal strain and linear tensile ratio of 2150% and 400%, respectively. Meanwhile, because of the enlarged contact area between triboelectric layers, the output power density of the MXene TENG with micro-crumples was highly improved by 36 times. Therefore, the as prepared sensor exhibited excellent sensitivity of 2.35 V kPa−1 under pressures from 0.3 to 1.0 kPa, which is superior to majority of the reported sensors based on tribo-/piezo- electricity. In addition, the sensor can be easily attached to human joints to capture and collect the complicated movement signals. By combining with Bluetooth transmission technology, wireless real-time monitoring was realized through transmitting human movement signals to a mobile phone App.