Theoretical And Experimental Study On Femtosecond Laser Processing Of Carbon Nanotubes Film

Carbon nanotubes film is a kind of carbon material with micro nano thickness.It has good optics,mechanics and high conductivity,which can be used in flexible equipment,micro sensors and solar cells.Femtosecond laser is an effective method for the precise fabrication of carbon nanotubes film because of its high peak power and short pulse width.In this paper,the theory and experiment of femtosecond laser processing of carbon nanotubes film are studied.First of all,the physical process of interaction between femtosec ond laser and carbon nanotubes film on time scale is discussed in this paper.The two temperature model of interaction between femtosecond laser and carbon nanotubes film is described.The change rule of electron and lattice with time in the process of interaction between laser pulse and material is studied by using COMSOL,and the ablation threshold of material at different wavelengths under 300 fs is discussed.Secondly,the influence of femtosecond laser ablation on carbon nanotubes film is studied on the basis of theoretical research.Different femtosecond laser parameters(wavelength,pulse energy,number of pulses)are used to study the ablation of carbon nanotubes film by optimizing the way of drilling.The results show that the shorter laser wavelength can ablate the smaller material ablative aperture,but produce relatively larger carbon nanotubes ejecta;the laser pulse energy is the main factor affecting the ablative aperture of carbon nanotubes film and increases with the increase of pulse energy;The number of pulses has no obvious effect on the area and depth of ablative aperture.At the same time,the experiment of femtosecond laser cutting carbon nanotubes film was carried out on the basis of microporous research and Raman spectrum.High laser e nergy will make the edge of carbon nanotubes film re-coagulate and damage the surface of the material.Reasonable laser parameters can achieve the complete cutting of the material,and the physical composition and defect degree of the cutting position have no obvious change compared with the original material.At last,a good cutting of carbon nanotubes film was obtained under the optimized laser parameters.Finally,in order to apply the carbon nanotubes film to the flexible electronic equipment,the tensile properties of the carbon nanotubes film cut by femtosecond laser were studied.In this paper,the deformation process of carbon nanotubes film was discussed,and the different laser energy cutting carbon nanotubes film stretching along the tube bundle axial and radial direction was analyzed.The higher laser energy damaged the original structure of the material,resulting in the reduction of tensile strength,Young's modulus and elongation at break in varying degrees.The results of the interaction betwe en femtosecond laser and carbon nanotubes film are of great significance for the application of materials.