Preparation And Properties Of Elastic Electronic Devices Based On Wrinkled Nanofiber Membranes

The rapid development of modern science and technology has led to the rise of a number of new technologies,including human health technology research.People pay more and more attention to their own health problems,how to effectively monitor human behavior,timely and effective feedback related information has become the focus of scientific researchers in recent years.However,traditional sensors used to collect information are not suitable for this field because they are uncomfortable to wear,easy to be damaged,and the fault tolerance rate of human body is not high.Compared with traditional sensors,flexible electronic devices are comfortable to wear,thin and practical,and have become the mainstream wearable sensors.Because of its advantages of simple preparation,strong mechanical properties and low price,polymer has been widely favored as the base material of flexible sensor.In this paper,a polymer stretchy sensor based on electrostatic spinning and centrifugal spinning is prepared,and a special fold structure based on material properties is innovated.Polyacrylonitrile(PAN)and polyurethane(PU)were used to prepare PAN/PU composite nanofibers with pleated structure under the combined action of centrifugal force and electrostatic force.This pleated structure gave PAN/PU strong tensile properties and further improved the strength of the fibers.The material can withstand up to 320%deformation and the maximum stress is about 2.75mpa.Compared with pure PU fibers obtained by the same technique,the mechanical properties are similar.Two conductive materials,flake graphene and copper sulfide,were loaded on folded PAN/PU composite fibers by two loading methods.The materials were further characterized by scanning electron microscopy,energy spectrum analysis,tensile testing and electrical properties.The composite fibers loaded with flake graphene have a maximum deformation tolerance of 80%and a maximum stress tolerance of1MPa.Initial resistance is 4.9 K?;Draw ratio reached 18%,to 1 M?resistance.The mechanical and electrical properties of materials need to be further improved.The composite fiber loaded with copper sulfide has a maximum deformation tolerance of230%and a maximum stress tolerance of 0.55MPa.Under the deformation of 80%of the sensor,the resistance change rate reached 3000%,while after 200 times of stretching,the resistance change rate only changed by 10%compared with that before stretching,indicating that the sensor has good repeatability.Finally,systematic integration of the PAN/PU@Cu₉S₅ composite sensor was carried out,and a set of systems for monitoring human behavior were built,which greatly enhanced the usability of the sensor in real life and guaranteed the safety,which has great significance for the field of human health.For stretchable elastic sensors,graphene materials and thin film materials are mainly used at present.The manufacturing process is complicated and the cost is high.Therefore,using polymer as material this time not only makes the process simple and costs low,but also provides a good idea for making elastic sensor in the future.