Preparation And Application Of Titled Cone Array Structure Based On Femtosecond Laser

The organisms in nature have experienced hundreds of millions of years of survival and the fittest,and now form a relatively complete and mature ecosystem.Learning from diverse organisms in nature,researching and analyzing the surface structure and functional characteristics of organisms is an important topic in the development of new functional materials.In recent years,researchers have developed a variety of micro-nano processing methods to prepare a variety of structures on the surface of materials.As a new type of micro-nano processing technology,femtosecond laser processing technology plays an important role in the current micro-nano manufacturing field due to its high instantaneous power,high processing precision,no mask,and no material limitation.This topic combines femtosecond laser processing technology with bionic design concept,and successfully prepares anisotropic tapered cone array structure by reasonably selecting processing parameters.We provide theoretical support for the functional expansion of the structure through principle analysis and model establishment,and finally successfully realize the functions of droplet handling and underwater bubble transportation under vibration conditions.The main work of the full text includes the following parts:(1)From the analysis of the interaction mechanism between the femtosecond laser and the material,it is known that the femtosecond laser ablating the surface of the material to obtain the micro-nano structure is a rather complicated process.By selecting the appropriate processing materials and suitable processing parameters,and analyzing the influence of processing parameters on the structural morphology,the optimal laser processing parameters were used to successfully prepare the oblique pit array structure with controlled depth and pitch on the surface of the silicon wafer.The corresponding tapered cone array structure was obtained by transfer onto the PDMS.(2)The effects of different bevel pitches on the static infiltration and dynamic wettability of the material surface were systematically investigated.Through the regulation of infiltration,the function of the horizontal movement of the droplet on the surface under vertical vibration is realized.A related theoretical model is established to describe how the force of vertical vibration is achieved by the asymmetry of the force.This theoretical analysis helps to develop and optimize new structural surfaces,enabling the function of manipulating droplets by the interaction of contact lines and interfaces.(3)Based on the oblique cone array structure,related applications of underwater bubble transportation are developed.According to the shape and diffusion mode of underwater bubbles on the surface of the structure,it is proposed that the anisotropic surface can also realize the problem of bubble transportation according to the difference of the pinning force.Finally,the feasibility of transporting bubbles on the surface of the structure under water was successfully proved by experiments.It demonstrates the unique superiority of the tapered cone array structure in microfluidic manipulation,and has certain significance in the development and design of microfluidic devices.