Fabrication Of Surface Micro-nano Wrinkles And Research On Its Application In SERS

To Manufacture the micro-nano wrinkles,we can utilize the diffidence of the elastic coefficient of the rigid film and elastic substrate and control process of technics.In general,the wrinkles are manufactured by tow ways which are mechanical stretch and thermal expansion.The different structures of wrinkles can be obtained by controlling the direction of drawing and the way of releasing stress.By releasing thermal stress after the oxidation treatment has been done or the metallic film has been deposited on the elastic substrate which has been heated in advance,we can get disordered micro-nano wrinkles.The traditional technics by which we can do some technics,such as sputtering and pyrolyzation,on the microstructure and obtain the structure of wrinkles whose property of Raman enhancement is ordinary are relative complex.In this paper,the thermal expansion method is used to control the stress release and the mask plates are introduced as the boundary effect which affects the formation of the wrinkles which will be applied to the SERS substrate.Specific contents are as follows:Firstly,the technological process of the preparation of the thin film wrinkles is described.The technics includes the preparation of PDMS substrate,the structural design of mask plate and the treatment of magnetron sputtering etc.The structure of the mask plates whose gap are between dozens of microns and one hundred microns and the thickness is 300?m or500?m is striped.By controlling the experimental conditions,such as sputtering time,sputtering temperature and the size of mask plates,we can control the thickness of the thin film,retraction stress and boundary conditions of the formation of wrinkles and then control the structure and the size of the wrinkles.Through the control of the mask plate and the use of the way of thermal expansion,sinusoidal surface film wrinkles can be obtained by controlling the sputtering time.At the same time,through the use of AFM to characterize the surface morphology of the wrinkles,we can get the information by which we can get the aspect ratio of the wrinkles of the wavelength and amplitude of the wrinkles.Tow kinds of typical wrinkles which are sinusoidal nested membrane wrinkle and surface micronano wrinkle can be obtained by controlling the sputtering time and the thickness of the thin film.Secondly,in the case of preferably controlling the forming of the thin film wrinkles,it will be applied to the SERS substrate and its enhanced properties will be studied.This paper mainly introduces the preparation method of the SERS substrate and use rhodamine R6G as the probe molecule and laser Raman spectrometer whose model is HORIBAHR800 as detector to detect the signal of SERS substrate.Under the conditions of the experiment,the enhanced performance of the SERS substrate is optimal investigated by controlling the thickness of the film,the sputtering temperature and the size of the mask plate.In this experiment,the performance is better when the temperature is 100 degrees,the film thickness is 300?m and the size of mask plate is 30?m.In addition,the enhanced performance of the sinusoidal nested membrane wrinkles and the surface micro-nano wrinkles is tested.At last,the lowest concentration of rhodamine R6G which can be detected by SERS substrate is 10^-13mol/L which is smaller than that of the general SERS substrate having been explored.