Stretchable, Conducting and Large-Range Monitoring PEDOT: PSS-PVA Hydrogel Strain Sensor

Highly stretchable conducting polymer hydrogel strain sensors are widely used in many wearable electronic devices such as human exercise health monitoring, human-machine interface, and electronic skin. Flexible strain sensors can convert the sensed mechanical tensile deformation into electrical signal output. The structure and detection principle are simple. However, the strain sensors reported so far still face the problems of low stretchability, poor mechanical property and low sensitivity. In this work, we prepared an anisotropic tough conducting polymer hydrogel via a simple ice template-soaking strategy. The ice template can effectively control the growth of ice crystals, thereby forming a honeycomb-like micro-nano structure network; then the frozen hydrogel is immersed in a high concentration of sodium citrate salt solution. During the soaking process, phase separation of PEDOT:PSS and strong aggregation and crystallization of PVA were induced. The prepared conductive polymer hydrogels have excellent tensile properties, mechanical property and stable resistance changes. Conductive polymer hydrogels can be used as wearable strain sensors for detection of minute physiological movements and motion monitoring under large strains.