Fabrication And Properties Of Cellulose/PAA Double Network Ionogel Based Strain Sensor

In recent years,the rapid development of wearable electronics in the field of artificial intelligence,medical health and human-computer interaction equipment has attracted widespread attention from researches.Ionogel combines the advantages of hydrogels and conductive materials,at the same time ionogel has a wide temperature use range and good environmental stability,which is an ideal material in the preparation of flexible sensor.However,the application of ionogel in flexible sensor is still limited by weak mechanical strength and poor stretchability.The preparation method of ionogel with high strength is complicated and the period is long.Preparation of ionogel by in-situ photopolymerization has the advantages of simple,fast and low cost.Therefore,it is of great significance to prepare ionogel with high mechanical strength by photopolymerization.In this study,Cellulose/polyacrylic acid(PAA)double-network ionogel was prepared by photopolymerization.The physically cross-linked cellulose networks were highly entangled with the chemically cross-linked PAA networks,therefore this ionogel had good mechanical properties.The tensile strength of the ionogel is 0.6 MPa and the elongation at break can reach 720%.This ionogel had good surface adhesion ability,it could adhere to a variety of substrates,and the cyclic adhesion strength on glass surface was 30 kPa.This ionogel had good thermal stability and a low glass transition temperature(-41℃),which could be used at low temperature.The flexible strain sensor based on ionogel showed good electrical and mechanical performance.The guage factor(GF)of the ionogel sensor increased with the increase of strain and reached 2.07 when 100%strain was applied.Ionogel sensor could detect large strains and small strains and the relative resistance of ionogel sensor showed linear correlation with the change of strain and its respone time is very short(300ms).In the experiment of repeating loading-unloading process under 50%strain,ionogel sensor showed high stability and repeatability.The flexible sensor could detect the movement of different parts of the body,and also could be used as temperature sensor.