Flexible and wearable multilayer structure fiber sensor for motion and human physiological signal monitoring

The development of flexible piezoresistive sensors has increasingly attracted widespread attention due to their various potential applications in wearable devices, human–machine interfaces, and health monitoring systems. Developing high-performance sensors that can accurately monitor movement and human health monitoring is very necessary. This study uses silver nanoparticles, MXene, and polypyrrole to prepare conductive fabrics based on various fabrics through layer-by-layer encapsulation. Finally, conductive fabrics with different layers were encapsulated to prepare a multilayer fiber sensor. Next, the series piezoresistive performance of sensors made of different fabric materials and sensors with different layers were tested. The experimental results show that the sensor prepared has the best performance when the selected fabric material is mulberry silk and the number of layers of the fabric is five. After testing, the sensitivity of the sensor is 4.9029 at low strain and 0.7901 at high strain. Moreover, it exhibits good stability during 1600 compression-release cycles and temperatures range from −20 to 60°C. The designed sensor performs well in motion and human physiological signal monitoring. This study provides new ideas and references for the design and research of multilayer fiber sensors.