fig1

Figure 1. Design, fabrication and application of the sensor. (A) Schematic diagram illustrating the preparation of MXene by the hydrochloric acid-etching method; (B) SEM image of the MXene sheets; (C) Schematic diagram illustrating the fabrication of the MXene-based piezoresistive layer and the interdigital silver electrodes on dust-free paper and the assembly of the sensor unit; (D) Schematic diagram illustrating the sensor unit integrated into the airbag pillow for snoring monitoring and the sensor array for head posture recognition by machine learning. SEM: Scanning electronic microscopy.