Facile preparation of porous MXene/cellulose nanofiber composite for highly-sensitive flexible piezoresistive sensors in e-skin

Flexible pressure sensors with porous structures have a wide range of applications in many fields, including in flexible electronic skin, medical diagnosis, and human–computer interaction. As such, the fabrication of pressure-sensitive layers with porous structures capable of superior performance has become a significant research hotspot. Herein, we report a mechanically-sensitively enhanced structure of surface patchy protrusions and porous composites which can be used to accurately monitor limb movement, pulse, and breathing. Notably, the flexible pressure sensor exhibits high sensitivity (21.457 kPa −1 ), wide detection range (0.11–11.022 kPa), rapid response/recovery time (41.84 ms/20.82 ms), and excellent stability and cycle repeatability (up to 6000 cycles). Further, the pressure sensor array can act as an electronic skin to detect the pressure distribution. We further propose a newly developed miniaturized flexible wireless feedback system equipped with five pressure sensors. Using the detected pressure as input, the accurate recognition of nine gestures (98.22 %) was achieved with the help of a convolutional neural network (CNN) model.