Research On Bionic Superhydrophobic Surface Based On Projection Micro-stereolithography 3D Printing Technology

A super-hydrophobic surface is a surface with a static contact angle of a water droplet on it larger than 150°.In the past century,more and more researchers involved such a field because of the great potential applications for super-hydrophobic surfaces in many fields such as heat transfer enhancement,surface drag reduction,oil-water separation,material anticorrosion,as well as micro-droplet manipulation.Researchers have developed many methods for preparing biomimetic super-hydrophobic surfaces during long-term research,such as vapor deposition,electrochemical methods,spin coating methods,etching techniques,self-assembly methods,etc.In this paper,inspired by springtail,a super-hydrophobic surface with micromushroom structures was successfully prepared based on the projection micro stereolithography 3D printing technology,the characteristics and mechanism of superhydrophobicity are studied and revealed systematically.It provides a new preparation method and theoretical design for the controllable fabrication and application of bionic super-hydrophobic surfaces.The main research contents are as follows:(1)Inspired by the super lyophobic properties of the springtail,the microstructure of the cuticle was observed in detail and the accurate 3D model was reconstructed.Finally,the P?SL 3D printing technology was used to precisely fabricate it.(2)The morphology,adhesion and wetting properties of the samples were characterized in detail.Based on lattice Boltzmann method,the superhydrophobic mechanism of mushroom structure and the factors affecting surface wetting property were systematically studied.Experimental results showed that the surface structure of the prepared sample was very mushroom-like with super-hydrophobic properties,and the contact angle of water with it could reach 171°.In addition,the present surface also had a good adhesion to water droplets,so the prepared surface also exhibited a "petal effect",that is,the water droplets on the sample would not fall off even if the sample surface was turned over 180°.(3)By precisely controlling the geometric parameters such as the morphology,size and gap of the microstructures,the wettability and adhesion force of the printed biomimetic surface can be well controlled..The contact angle of water on such a functional surface can be adjusted from 55° to 171°,while the adhesion force of a water droplet on it can be varied from 71?N to 99?N.Based on these results,we also explored its application in droplet non-destructive transfer,droplet coalesce and serving as a microchemical reactor.(4)Based on the original material,the hydrophobic modification was carried out to investigate,and a hydrophobic resin with a contact angle of about 105° was prepared.In addition,the water droplet bounce on such a functional surface was also experimentally studied.All in all,this paper presents a super-wetting surface with controlled wettability manufactured based on a P?SL based 3D printing technology.In addition,the application for micro-droplet manipulation with our printed functional surfaces has also been explored.The present study opens a gate for the structure design in the fields of biomedicine,analytical chemistry,and microfluidics.