Application Research Of Self-repairing And Temperature-resistant Strain Sensors Based On Multifunctional Ge

Conductive hydrogel can achieve high sensitivity and excellent mechanical properties,and has excellent characteristics such as biocompatibility and hydrophilicity.It has a very good application prospect in the preparation of flexible sensors.Flexible sensors are electronic devices that can monitor stress,pressure,temperature,and human movement.Therefore,it can play an important role as the next generation of intelligent wearable devices in artificial intelligence,flexible energy storage technology,and health monitoring devices.A large amount of water in traditional conductive hydrogels inevitably freezes from below zero temperature,and tends to lose water in high temperature environment and become hard and fragile,losing flexibility and mechanics,which greatly limits the use of hydrogels in extreme environments.At present,although excellent research results have been achieved in the research of hydrogels,it is still a huge challenge to realize the long-term use of hydrogels in low and high temperature environments.In addition,the hydrogel-based flexible sensors also need to have excellent flexibility,drying resistance and self-healing properties.These properties ensure that the sensor can still accurately monitor human movement in extreme environments.Based on the above,we prepared an organohydrogel with mechanical,self-healing,self-adhesive and temperature resistance and applied it to the sensor.The main research work is as follows:1.Conductive hydrogels with moisturizing and freezing-tolerant properties have great potential applications in the field of flexible electronics because of their excellent flexibility and conductivity under harsh climatic conditions.Herein,we constructed a stretchable,self-healing,self-adhesive,transparent,anti-drying,and anti-freezing conductive organohydrogel by a simple one-step method.Owing to the designed double-network structures,multi-dynamic crosslinks and H₂O/DMSO binary solvent systems,the resulting organohydrogel demonstrates superior stretchability（2400%strain）,prominent self-healing capability（1550%strain for the healed organohydrogel）,outstanding anti-freezing property（below-50℃）,and excellent moisture retention（80%after 7 days）.The as-assembled sensor based on this organohydrogel possesses a relatively high sensitivity（GF=2.8）and a wide linear sensing range（0-1500%）,ensuring the reliable and accurate monitor for various mechanical deformations and intricate human motions.Meanwhile,the fascinating features of organohydrogel sensors are that they can not only distinguish effectively the direction of human motions but also judge the temperature changes.More importantly,the pristine and healed organohydrogel sensors can still maintain their response functions even under an extremely low temperature of-50℃,manifesting the superior capabilities to withstand mechanical damages and endure harsh climatic conditions.Interestingly,the as-prepared organohydrogel displays adjustable optical properties in different polar solvents and can serve as a dynamic information memory device for recording,erasing and encrypting information.This multifunctional organohydrogel may be a promising material applied in novel flexible electronics and information-recognition platforms in harsh environments.2.Conductive hydrogels are considered as highly promising candidates for fabricating flexible and wearable electronic devices.However,traditional hydrogels inevitably lose their inherent characteristics under extremely climatic conditions,which seriously hinder the practical application of hydrogel-based electronics.Herein,a toughened,self-healing,self-adhesive and transparent conductive gel(PAA-Zr⁴⁺/Gly/IL)with extraordinary temperature adaptability is prepared via a one-step photopolymerization of acrylic acid（AA）monomer in Gly（glycerol）-IL（[Bmim]Cl）hybrid solvent containing Zr⁴⁺ions.The carboxyl-Zr⁴⁺coordination bonds and multiple hydrogen bond interactions within the gel networks contribute to the excellent mechanical property（0.42 MPa at 1436%strain）and self-healing capability.Meanwhile,the synergistic effects of Gly and IL endow the as-prepared gel with significant temperature tolerance,which can even maintain remarkable flexibility and mechanical strength after being stored at-50,20 and 50℃for 30,30 and 10days without extra sealed packaging.Impressively,the PAA-Zr⁴⁺/Gly/IL gel-based sensors exhibit favorable sensitivity and repeatable response capability upon both mechanical and thermal stimulation.As a strain sensor,it demonstrates wide sensing range（5-700%）,prominent signal stability（1100 cycles at 300%strain）and precise human motion detection along two opposite directions.As a thermal response sensor,it can accurately and reliably sense temperature changes in a wide range from-50 to 50℃.Noticeably,owing to the significant self-healing property and temperature tolerance,the pristine and healed PAA-Zr⁴⁺/Gly/IL gels after long-term storage at various temperatures（-50,20 and 50℃）are also capable of demonstrating a recognizable and reliable signal response when detecting tensile strains and prosthetic finger bending movements in normal and harsh environments.This work provides a powerful strategy to design versatile conductive elastomers with broad and long-term temperature tolerance for future flexible and wearable electronics.