“…Water resources are vital for the survival of all species on earth. − With the gradual decrease of water resources and the urgency of human health requirements, the detection of water and human body fluids becomes more and more important. − Liquid sensors can be widely used in various applications, such as sewer leakage detection, , water level detection, urban water detection, environmental detection, urine detection, and sweat detection. , Designing a reliable, efficient, and multipurpose liquid sensor to reduce the unnecessary water waste and provide convenience for daily life has gradually attracted people’s attention. − A large number of liquid sensors have been reported, and some technologies have been converted into products. ,− Among the reported liquid sensors, metal materials were frequently used. Applications of ceramic sensing materials and semiconductor sensing materials were limited in some specific occasions due to their shortcomings of nondeformation, coldness, heaviness, and rigidity. − Therefore, it is of great significance to develop a versatile liquid sensor with light weight, low price, good flexibility, extensibility, rapid response, convenient operation, and high cycle stability. ,− Fiber liquid sensors will have apparent advantages in this regard because of their characteristics of self-stretching, high deformation, large specific surface area, and light weight.…”