Research On Performance Of Flexible Strain Magnetic Sensor Based On MNs&AgNWs-PDMS

In recent years,more and more researches have been devoted to flexible electronic devices and have achieved certain results in wearable systems.At the same time,magnetism as a natural phenomenon is widespread in natural phenomena and human life.The commonly used magnetic field detection methods are mostly based on rigid materials.Combining magnetic nanoparticles with flexible electronic sensors,according to the anisotropic magnetoresistance effect of magnetic materials,breaks through the rigidity characteristics,and further achieves the purpose of magnetic field detection of flexible electronic devices.Analyze the effect of this structural principle on the sensitivity of the sensing.In this thesis,a flexible strain magnetic sensing film with high sensitivity and which can be used to detect magnetic fields is proposed.The flexible strain magnetic films with different mass ratios of MNs&AgNWs nanocomposites and sandwich structure were prepared by template method.The electrical,strain sensing and magnetic sensing properties of the films were tested and analyzed.Experimental results show:1.The Fe₃O₄ material synthesized by hydrothermal method is a magnetic pellet with a diameter of about 500 nm,and the material has good single crystal characteristics and high saturation magnetization.The silver nanowires synthesized by the polyol thermal method have a length of about 26?m,the magnetic nanocomposites were obtained by mass ratio of two kinds of nanomaterials to 1:1.The flexible film was prepared by template method,and the electrical performance test showed that the flexible strain magnetic sensor has good ohmic characteristics,and it was found that the sensor has certain magnetic field detection,the detection range is 20mT.2.Optimize the selection of magnetic nanomaterials,synthesize FeCo nanomaterials with better magnetostrictive effect by hydrothermal method,and optimize the mass ratio of FeCo and AgNWs.The electrical properties,strain properties and magnetic field testing of the flexible sensing film were tested.It was found that the flexible stress magnetic films based on FeCo&AgNWs have good ohmic characteristics,and when the mass ratio of FeCo to AgNWs is 1:5,the sensor has the largest strain sensitivity coefficient of 24,at the same time,the sensor has the largest resistance change rate of 0.28 in the magnetic field environment.The magnetic detection range of the flexible strain magnetic film based on FeCo&AgNWs is expanded to 0.4T?400mT?,which is about 20 times larger.In summary,magnetic nanoparticles are added to the sensitive unit of the flexible electronic device,and the magnetic field can be detected by the magnetoresistance effect of the magnetic material.The sensitivity coefficient of strain for flexible strain magnetic sensing film is also greatly improved,and the magnetic strain detection performance of FeCo&AgNWs based on FeCo&AgNWs is better than that of Fe₃O₄&AgNWs.