Intelligent hydrogel on–off controller sensor for irrigation

As a functional material, hydrogels hold promise in agricultural irrigation, potentially solving the problem of low utilization of irrigation water from the source. To enable more intuitive monitoring of soil moisture and achieve on-demand irrigation, a conductive hydrogel is being explored as a solenoid valve controller for intelligent irrigation. Here, intelligent hydrogel poly (acrylic acid-co–N-methylolacrylamide)/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, P(AA-co–N-MA)/PEDOT:PSS, with a dual network was synthesized under mild conditions through Na 2 SO 3 -APS (ammonium persulfate) initiation system. The structural design endows the hydrogel with excellent mechanical properties (elongation at break up to 2400%) and sensitive sensing performance (gauge factor, GF, is 8.14). The anti-fatigue properties of the hydrogel have proved that the material has good durability and good service life as a sensing material. In addition, by incorporating the relationship between moisture and conductivity, the hydrogel could be utilized as a controller for irrigation valves, enabling intelligent irrigation and effective conservation of water resources through soil moisture monitoring. Graphical abstract The intelligent hydrogel P(AA-co–N-MA)/PEDOT:PSS could be utilized as a controller of solenoid valve for irrigation through soil moisture monitoring.