Research On Fabrication Technology Of Flexible Anti-metal RFID Crack Sensor Tag Based On Screen Printing Technology

The main structure module of aerospace vehicle is the key component of high-end equipment in aerospace field,which has the characteristics of high material cost,difficult processing and long processing time.Remanufacturing the main structure module of aerospace vehicle has significant economic benefits,but it also brings a series of technical challenges.The main structure cabin of spacecraft is prone to crack under the action of fatigue load and corrosion,which will bring serious safety hazards to the operation of spacecraft.Therefore,before remanufacturing and repairing,it is necessary to detect and quantitatively characterize the cracks through nondestructive testing technology.Compared with non-destructive testing technology,structural health monitoring technology is more focused on the real-time damage monitoring of components in service.Structural health monitoring technology collects the operation information of components through the sensor elements arranged on the surface or embedded in the components,so as to achieve the purpose of real-time monitoring the operation of components.Passive wireless RFID crack sensor tag is an effective method to detect and monitor the cracks in the dangerous parts of the main structure cabin of spacecraft.How to prepare RFID tags that can adapt to the working conditions of the main structure cabin is an urgent problem.In order to prepare RFID crack sensor tags with good metal resistance and flexibility,the crack sensor tags can be applied to the main structure cabin of spacecraft This paper mainly studies the preparation method of RFID crack sensor tag based on screen printing technology.This paper mainly includes the following three parts:Firstly,the influence of metal environment on the performance of RFID tag is analyzed,and the methods to realize anti metal RFID tag are summarized.Secondly,the crack sensing principle of RFID tag based on microstrip antenna is analyzed,and the design principle and method of flexible anti metal RFID tag are proposed.Finally,according to the working requirements of tag,the tag chip is selected,and the tag antenna is simulated by electromagnetic simulation software The characteristics of the tag are that it can be used not only in the metal environment and curved surface environment of the main structure cabin of the spacecraft,but also in the simple structure,which is suitable for the screen printing process.Secondly,the influence of screen printing process on the performance of the designed RFID tag is studied.The RFID tag designed in Chapter 3 is prepared through the printing process.The screen printing process and curing process of the tag antenna are studied.The reading distance of the tag is taken as the evaluation index of the tag performance,and the best screen printing process and ink curing scheme of the tag antenna are determined,so as to prepare high-quality RFID tags It lays the foundation of RFID crack sensor tag.Thirdly,the flexible anti metal RFID crack sensing tag is prepared,and then the flexibility and anti metal of the tag are tested,and the crack sensing performance of the tag is verified.Experiments show that the RFID tag has good metal resistance.When placed on metal,the reading distance of the tag can reach more than 2.5m in 860MHz-960 MHz.Besides,the label has good flexibility.When the conformal shape is on the foam cylinder with diameter of 25 cm,the reading distance of the label can still be above1 m.Finally,the crack sensing performance of the tag is verified.The threshold power of the tag decreases with the increase of the crack length and depth of the metal component,so the tag can be used to identify and characterize the surface cracks of the metal component.