High-Sensitivity Composite Dual-Network Hydrogel Strain Sensor and Its Application in Intelligent Recognition and Motion Monitoring

Flexible electronic sensors are attracting more and more attention because of their outstanding flexibility and foldability. Based on this background, a composite hydrogel with excellent flexibility, good stability, and high sensitivity is prepared in this work. This high-performance hydrogel is composed of polyacrylamide, sodium alginate, MXene, and PEDOT:PSS through dynamic supramolecular cross-linking. The electrical conductivity is significantly enhanced by the addition of the conductive polymer PEDOT:PSS and MXene. Hydrogel conductivity increased by 150% with the addition of conductive materials at the same tensile strain. It exhibits high sensitivity (GF = 1.99) and excellent linearity over a wide operating range of 1000% of strain, which ensures the detection performance of the hydrogel sensor under large strain conditions. In addition, it has excellent repeatability (600 cycles) and fast response/recovery times (0.624 s/0.912 s). Due to this excellent performance, it was made into a smart sensor to explore its application in smart electronic skin. The hydrogel sensor and data acquisition module were integrated for real-time monitoring of pressure. We combine it with deep learning algorithms to provide a new solution for human motion recognition, such as joint flexion, facial expression change, health monitoring, and handwriting recognition.