Design,Fabrication And Antifouling Property Of Bionic Microcilia Array Surfaces

Marine fouling is the accumulation of micro-and macro-organisms on immersed surfaces which lead to economic,environmental or safety-related negative effects.Traditional organic tin antifouling materials is famous for broad spectrum and efficient sterilization ability,which provided the surface with effective marine fouling resistance.However,several studies indicated that TBT-based compounds had adverse effects on non-target marine organisms such as oysters due to its high persistence and accumulated toxicity.Hence,it is urgent to develop environment-friendly antifouling materials to combat the problem of Marine fouling.In recent years,with the development of science and technology,the rough micro/nano structure of biological surface gradually emerges as an ace in the hole in the field of Marine antifouling field.Differing to conventional fungicides,structured surfaces,such as lotus leaf surface,shark skin and pitcher plant surface,can physically restrain the accumulation of biological fouling via air barrier and smaller contact areas,while achieving safe,environmental and broad-spectrum.Nevertheless,since this antifouling performance is based purely on static structural surfaces with a short-term anti-adhesion,as the structures are vulnerable in water systems.In this study,it was found that the fly wings surface modified with micro/nano cilia exhibits excellent antifouling performance,for which the fouling can be removed from the micro-cilia wing surface for its super-hydrophobicity in a short time and dynamic effects,such as wing shaking and leg brushing,in a long time.We explored the morphology features,wettability and dynamic cleaning behavior,revealing the internal antifouling mechanism of flies.Based on the principles of bionics inspired by flies,we designed and fabricated the magnetic response superhydrophobic micro-cilia surface and magnetically driven super-hydrophilic high aspect ratio cilia surface.The internal relationships between surface morphology,wettability,magnetic responsiveness,the dynamic behavior and antifouling performance was investigated respectively.The main research can be divided into the following points:1.Study on antifouling performance of fly wing surface:By analyzing the micro/nano structure morphology and wettability of wing surface,the super-hydrophobicity,anti-adhesion and drainage effects of cilia at different positions was studied,revealing the internal antifouling mechanism of ciliated surface.The results of dynamic antifouling experiments show that flies create unstable superhydrophobic interfaces by shaking their wings,which causes large droplets rolling off the surface.But the small droplets and organic dirt mainly rely on the leg scraping the wing surface of the auxiliary cleaning.The antifouling performance of flies is completely based on superhydrophobic surface and dynamic self-cleaning behavior,which belongs to the category of pure physical antifouling,providing new inspiration for the construction of new antifouling durable surface.2.The preparation and antifouling analysis of magnetically responsive superhydrophobic micro-cilia:Inspired by the fly wing surface micro/nano cilia hydrophobic properties,the micro groove arrays with different depth to diameter ratios were prepared by near ultraviolet photography,and the micro ciliary array with different sizes and morphology were modified by reversed the microarray mold and subsequently surface chemical deposition to obtain superhydrophobic structural surfaces.The magnetic Fe₃O₄ nanoparticles(Fe₃O₄ NPs)were doped into the bionic cilia to enhance their mechanical properties to effectively resist the gravitational interaction between the cilia and the substrate.Meanwhile,the addition of magnetic responsive materials could make bionic cilia swing dynamically under the circular movement of a magnet,which greatly improved the surface self-cleaning performance of bionic cilia.As a result,the micro cilia arrays with a slenderness ratio of 3,an upright array on the surface,could effectively overcome the gravitational interaction between adjacent cilia.After surface hydrophobic treatment,the static contact angle is greater than 156.9^o±1.6^o,while the rolling angle is less than 2.5^o±0.3^o.Because of its excellent superhydrophobicity,the droplets take the stained gravel away from the bionic surface.After magnetic properties were applied to the surface,the dynamic surface induced droplet to detach from the surface at a smaller rolling angle(1.2^o),which optimized the bionic superhydrophobic surface and selectively controlled droplet fall.3.The preparation and antifouling performance of magnetically driven multifunctional cilia with high aspect ratio:Inspired by the micro cilia structure of fly wing surface and the antifouling cooperation with leg brush,utilizing paraffin wax material with low surface energy as reverse mold material,this work design micro molds and prepare high aspect ratio(with a ratio of 15)magnetically controlled submicrociliary surfaces(HMCS)by reverse mold method,which solves the problem of high aspect ratio structure processing.In addition,the HMCS exhibits"sweeping"motion under an external magnetic field.Research suggests that the bionic cilia oscillates regularly and can effectively remove sand and dirt from the surface driven by an external magnet with a speed of 100 rpm.On this basis,a hydrophilic polyethylene glycol(PEG)hydrogel was grafted on the cilia surface to enhance its anti-protein adhesion property in a short time.In summary,the bionic magnetically driven antifouling cilia structure developed in this work provides a new idea and method for the preparation of omnidirectional dynamic antifouling surfaces.