Development Of In-situ Spectral Tensile Testing System For Flexible Materials

Compared with rigid materials,flexible materials have the characteristics of stretchability,bendability,and torsion.Common flexible materials,including high molecular polymers,elastic and plastic crystals,can maintain their own structure under the condition of large strain.It is destroyed and exhibits relatively stable optoelectronic properties,thus showing rich research value and broad application prospects.In the past few decades,with the development of flexible electronics and flexible photonics,flexible materials have gradually demonstrated their advantages in wearable,sensing,energy storage devices and devices,etc.,attracting more and more researchers.s concern.Nowadays,various ex-situ flexible material testing methods are very common and have quite mature technology.In situ material testing machines are mostly used to study morphological structures and electrical properties,but there are few reports on in situ spectral testing during stretching,which is limited by the volume and optical path structure of existing stretching instruments,mechanics and spectroscopy.It is difficult to carry out the mechanical test at the same time,which makes it difficult to realize the correlation research of the mechanical and optical information of flexible materials.At present,the mechanical and spectral performance characterization of flexible materials is basically carried out independently.First,the universal material testing machine is used to complete the flexibility.The mechanical properties of the material are tested,and the spectrometer is used for spectral correlation tests after the end.And most of the existing in-situ testing equipment for flexible materials has the limitation of nonmodularization and the same machine.In view of the above problems,this paper develops a general flexible material mechanics and optical in-situ spectroscopic testing system.This system should have the characteristics of modularization,small size,and structure suitable for various optical paths.The in-situ spectral tensile testing system for flexible materials developed in this paper is a testing machine for mechanical and spectroscopic testing of flexible materials.The test system is divided into three modules: tensile and force measurement module,spectral test module,control and data acquisition module,each module can perform actions independently,and at the same time,the mechanical and The correlation information of spectroscopy enables in-situ spectroscopy testing,which overcomes the limitation of the traditional flexible material testing machine that is stretched first and then measured.The main contents of this paper are as follows:1.Describe the overall design process of the in-situ spectral tensile testing system for flexible materials.The design scheme and target functions of the three modules,namely,tensile and force measurement,spectrum test,control and data acquisition,are discussed.Firstly,the hardware and materials are selected and designed for the given functions,including the motor for realizing the stretching function and the resistance strain system for force sensing and measurement.Next,the mechanical structure is designed and processed to complete the fixing and fixing of each system component.connect.Finally,by designing the optical path structure,the above tensile test platform is integrated into the optical system to complete the in-situ spectral measurement.2.The design of the control module is described.Firstly,the overall control signal flow of the flexible material mechanics and optical correlation test system is analyzed,and the control module design is divided into two aspects: hardware design and software design.In terms of hardware,first select the appropriate power supply for the circuit,then select the appropriate single-chip microcomputer and cooperate with the design of the circuit for driving the motor.Finally,in order to enable the host computer to communicate with the single-chip microcomputer,the data collection circuit and the mutual communication circuit are designed.In terms of software,the communication protocol between the host computer and the singlechip microcomputer is standardized first,then the program and algorithm of the single-chip microcomputer are written,and finally the control software interface of the host computer is written,which can realize the initialization,action control,and tension of the instrument platform.Sensor value acquisition,in-situ spectral data acquisition and storage,etc.3.Select two representative samples of flexible polymer film and flexible crystal,and complete the in-situ acquisition of spectra under two operations of stretching and bending,which verifies the reliability of the in-situ spectral stretching test system for flexible materials and its control software,analyze the test results,and finally put forward the direction of improvement and development for the shortcomings of the system as a whole.