The Research Of Flexible And Tunable Structural Color Based On Titanium Dioxide

Metamaterials was a concept that arised dating from 1960 s,the work made by Veselago.The basic understanding of metamaterials is that they have periodic artificial structures(metal or dielectric)which can couple with the electric and magnetic resonances under the incident electromagnetic field.The metamaterials usually behave antiphysical phenomenons such as negative refraction,abnormal reflection and so on,which always are utilized to realize special functions.But under the restriction of difficult fabrication of micro-and nanoscale 3D structures,researchers had to optimize the design or fabrication of metamaterial and then proposed the concept of metasurface,the planar metamaterial with subwavelength thickness,which exhibit advantages including ease of fabrication,thereby can realize more special physical functions.As the limitations of high losses especially in optical frequency range of metallic metasurface,dielectric metasurface can effectively make up these drawbacks in some degree.This article mainly designed the all-dielectric metasurface with structural color function,and explored its preparation process,and then proposed three methods of transferring the metasurface to flexible substrate material.By stretching the substrate material,the period of the metasurface array also changed,which can achieve dynamic control of the structural color.This project designed inverted trapezoidal metasurface structure by COMSOL Multiphysics multi-physics analysis software,and the tensile behavior of the metasurface on flexible material was simulated dynamically.The variation of the reflectance spectrum under stretch was obtained.Compared with the current research,this project firstly obtained a polarization-independent dynamic tunable structure.And then the project also explored the metasurface preparation process,especially the effects of stripping conditions(temperature and time).In addition,the method of transferring metasurface to flexible PDMS material was studied.Under the process of optimization,the wet method was finally determined as the best.Especially,there is no report on using this way to transfer metasurface either in China or abroad.Finally,the dynamic spectrum under simulationin was verified by optically measuring the metasurface structure with dynamic stretching.And utilizing the analysis about electromagnetic field in the dynamic stretching process,the rulesof dynamic variation was explained finally,which is caused by the competition mechanism of electric and magnetic coupling resonance.