Development of piezoresistive flexible sensor with dual-height cylindrical microstructure surfaces to achieve vehicle vibration monitoring

This research proposed a vibration monitoring device based on a piezoresistive flexible sensor with microstructured surfaces to achieve a simple acquisition of vibration information in the driver’s cabin of automobiles. The shape, size and arrangement mode of microstructures on the piezoresistive flexible sensor performance were investigated by finite element simulation. The polydimethylsiloxane/hydroxylated multi walled carbon nanotubes (PDMS/MWCNTs-COOH) composite membranes were prepared by the combination of high-pressure spraying and spinning coating method. The electromechanical response curves of the piezoresistive flexible sensor composed of a double-layer PDMS/MWCNTs-COOH composite membranes based on a dual-height cylindrical microstructure were tested. A vibration monitoring device was developed to process the signals obtained by the fabricated piezoresistive flexible sensor, and the vibration response of the car cab under different driving conditions was investigated. The results indicated that the cylindrical microstructure with small size can improve the sensitivity of the fabricated piezoresistive flexible sensor. Compared with the single-height and dual-height cylindrical microstructure, the piezoresistive flexible sensor with dual-height cylindrical microstructure can expand the detection range, and improve the linearity and sensitivity. The piezoresistive flexible sensor exhibits excellent performance, with a sensitivity of 1.774 kPa−1 and a detection range is 0–0.5 kPa. The above advances can improve the authenticity of the collected data, and provide a basis for the processing and analysis of the vibration signal before improving the noise, vibration and harshness performance of the vehicle.