Superhydrophobic Micro Pillar Fabricated By Meniscus Confined Electrochemical 3D Printing

Superhydrophobic microcolumn arrays have special water droplet wettability.It can be applied in the fields of anti-icing of wing,drag reduction of ship navigation,etc.However,the existing manufacturing methods still have some shortcomings,such as high processing cost,high requirements for processing equipment,low degree of process generality and so on.so,compared with the superhydrophobic surface construction technology,the general variable diameter superhydrophobic array technology is more difficult to be used in engineering practice and large-scale promotion.Here,a general metal microcolumn processing technology using electrochemical 3D printing was proposed.Constructing microcolumn structure and column array directly,to realize the integration of macro micro structure preparation.Subsequently,the column arrays were modified with low surface energy materials to obtain superhydrophobic properties.The main work of this paper are as follows.First,the theoretical analysis of the possibility of constructing electrolyte bridge on copper substrate was performed.Based on the process theory,the meniscus-shaped liquid/air interface was proposed to be divided into three parts,viz.,conical part,cylindrical part,and inverted conical part.This process is analyzed by COMSOL Multiphysics,and verify the feasibility of using meniscus confined electrochemical 3D printing technology to construct microcolumns with different shapes.Building a meniscus confined electrochemical 3D printing test platform,which consisting of anode nozzle,3D printer and DC power supply,etc.Designing the anode nozzle and nozzle fixture.Conical,vertical-cylindrical and inverted-conical micro copper pillars were deposited on copper substrate by using meniscus confined electrochemical 3D printing process.The growth of micro-copper column was analyzed to verify the relationship between diameter and height of copper column.The experiments results show that different shapes of copper microcolumns can be directly formed by the meniscus-confined electrochemical 3D printing process,which can be used as a general process to prepare column arrays with different shapes.Using concentration polarization model to analysis the processing rate of the meniscusconfined electrochemical 3D printing progress.Based on Nernst-Planck equation,the electrolyte concentration,electrode potential and relative humidity were selected to simulate the electrodeposition rate.The results show that the electrode potential and electrolyte concentration are positively correlated with the deposition rate,the relative humidity is negatively correlated with the deposition rate during the deposition process.Reliability of theoretical and simulation analysis is verified by deposition experiments.Obtaining the effect of process parameters on the deposition rate of copper microcolumn.The meniscus-confined electrochemical 3D printing process is used and the simulation and test results based on the aforementioned process parameters are combined.three types of Cu pillar arrays—conical pillar arrays,cylindrical pillar arrays,and inverted conical pillar arrays were constructed on the pure Cu substrate.The contact angle before and after surface energy reduction with fluoroalkylsilane is also measured.Compared with fluorinated sheet copper,the prepared micro-copper column by this process has excellent superhydrophobic property after fluorination.The experimental results show that this process can be used as a general process to prepare superhydrophobic column arrays of different shapes.