Preparation And Application Of Ionic Conductive Hydrogel-based Wearable Sensors

In recent years,flexible and wearable sensors have played a crucial role in electronics.As a flexible material,hydrogel has attracted extensive attention in the fields of human robotics,health monitoring,and soft electronics in smart electronics.The mechanical flexibility and compatibility aspects of hydrogels are closely aligned with the soft curvilinear contours of the human body.It has broad application prospects for the development of flexible electronic products（tactile sensors,wearable power supplies,robots,electronic skin,touch electronic screens and other）.It has become a developing trend that flexible materials gradually replace traditional rigid materials.Therefore,this paper designs a multifunctional integrated hydrogel that integrates transparency,stretchability,conductivity,and sensing.The main research contents and conclusions are briefly described as follows:In this paper,cellulose nanocrystals（CNC）were prepared by sulfuric acid hydrolysis,and then dimethyl sulfoxide（DMSO）/H₂O was used as the dispersion medium.A PVA/CNC ion-conducting organic hydrogel obtained by a one-pot blending/freeze-thawing method.The results show that:CNC has a rod-like structure and high hydrophilicity,which is a typical crystal structure of cellulose I;with the addition of a certain amount of CNC,the hydrogel has a three-dimensional porous structure;the PVA was uniformly dispersed in the structure and the tensile strength（0.16 MPa）was increased by 0.18 MPa;CNC uniformly forms crystals in the PVA system,reducing light transmission;Gauge Factor（GF:4.63）;the DMSO/H₂O system also endows the hydrogel with moisturizing properties;a self-powered hydrogel sensor device（voltage:0.859 V）and a pressure-strain sensor were self-made.Based on the CNC prepared by the above-mentioned sulfuric acid hydrolysis method,and then using glycerol/H₂O as the dispersion medium,a self-adhesive,anti-drying,and anti-freezing multifunctional PCGTA ionic conductive organohydrogel was obtained through a one-pot blending method/ultraviolet light technology.The results show that the construction of polyacrylic acid（PAA）/gelatin（Gel）double network and the uniform distribution of the two in the matrix enhance the mechanical properties;with the addition of CNC,the organohydrogels showed a three-dimensional porous network structure;chemical crosslinking increases the tensile strength of the hydrogel（0.16 MPa;584.35%）;exhibits reversible adhesion to a variety of substrate materials;after the addition of organic solvents and Al³⁺,the ionic conductivity increases,the water loss rate of the hydrogel decreases,the anti-water loss and antifreeze properties are improved,and the mechanical properties are also enhanced;high sensitivity（GF:6.47）and high stability;hydrogel-based wearable strain sensors can be used for applications in human motion monitoring.The main work of this paper first prepared CNC by sulfuric acid hydrolysis method,and then prepared ionic conductive hydrogel and hydrogel-based sensors with CNC,PVA,PAA,Gel,Na⁺,Al³⁺,and organic solvents（DMSO and Gly）as substrates.In the study of the influence of CNC and metal salt ions on organohydrogels and the sensing performance of hydrogel-based sensors.In addition,this paper expounds the structural characteristics and testing of organohydrogels in detail,which has reference significance for the research and application of polymer nanomaterial-enhanced ionic conductive hydrogel sensors.