Highly Stretchable Resistive Fiber Strain Sensor Based On Liquid Metal

Wearable technology is booming in the era background and market demand of big data,cloud computing,Internet of Things technology.The flexibility,portability,and comfort of devices are being demanded more than ever before.Sensors are the source of information acquisition in wearable devices,and flexible wearable sensor devices are playing an increasingly important role in health monitoring,sports training,human-computer interaction and other fields.However,the breathability,comfort,and adaptability of the irregular surface of the human body are still a huge challenge.Fortunately,fiber electronic devices with one-dimensional structure can adapt to complex deformations and capture relevant changes on the three-dimensional scale of the human body,providing a new solution for constructing new human-machine interfaces based on flexible wearable devices.As a new type of flexible electronic material,liquid metal has also received extensive attention due to its unique fluidity.In this paper,a four-layer coaxial composite fiber structure is proposed.Polyurethane fibers with excellent flexibility and stretchability are used as elastic substrates,and liquid metal is used to construct sensing structures on the surface of fiber cores due to its excellent ductility,fluidity,and electrical conductivity.A highly elastic resistive strain sensing fiber based on liquid metal is successfully prepared.The sensor has extremely fine fineness,low initial modulus,excellent electrical conductivity,wide working range,sensitivity,cycle consistency,response time and durability.It also has good waterproof performance and thermal effect.On this basis,the paper studies the sensing properties of liquid metal in this fiber,establishes a sensing theoretical model,and explores the key factors affecting the sensing fiber.In addition,the fibric sensor not only has a good ability to capture both large and small deformations of the human body,monitoring the movement of human fingers,elbows,wrists,throats and other parts of the body,but also can expand its sensing area to a two-dimensional plane through an array method to complete pressure position localization and object perception.The fiber sensor and its simple preparation method have broad application prospects in the fields of flexible wearable sensing and fabric sensing.