仿生微纳结构

BioinspiredScienceandTechnology,Name:SutudentID:,(Artificialrosepetalsurfacebasedonhierarchicalmicro-andnanostructures),ArticlewasfromThinSolidFilmsAccepted6July2011Availableonline18July2011,Introduction,Inthispaper,itpresentsanartificialrosepetalcomposedofhierarchicalmicro-andnanostructuresonapolymethylmethacrylatesurface.Thepetaleffectimpliesthatthesurfacehasahighadhesionforceinspiteofbeinginasuper-hydrophobicstate,whilethelotuseffectimpliesthatthesurfacehasalowadhesionforcewhenitisinasuper-hydrophobicstate,Manyresearchersareinterestedinbiologicalmicro-andnanostructuredsurfacesbecausethesesurfacesexhibitat-tractiveproperties,thelotuseffectstate,Micronstructureofmountains,Branchofnanoscalestructures,Thebutterflyswingwaterrollingdirectionfeature,waterskipperlegsstructure,Houselizardtoesstructure,Fromtheaboveexamples.wemayfeelthatnatureissowonderful.Especially.Whenweuseelectronmicro-scopeobservetheirmicrostructure,wefoundthatmostofthemarecomplexmicro-nanostructures,Buthowcanwefabricatethiscomplexmicro-nanostructures?,?,Fabricationofartificialpetalsurfaces,Thegeometricshapesandsizesofartificialpetalsurfacesweredesignedonthebasisofabiologicalrosepetal.Thesurfacestructuresofthebiologicalrosepetalconsistedofmicrostructures,suchaspyramids,andnanofoldsonthesurfaceofthemicrostructures,SEMimagesofthesurfaceandschematicrepresentationsofthegeometricmodels:(a,c)lotusleafand(b,d)redrosepetal.,Fromthepictures.Wefoundthattheapproximatefacetlengthandheightofthepyramidalmicrostructurewere15m20m,andthenanofoldswereapproximately700800nminwidth,Howtofabricatethemicro-nanostructure,Inthispaper,convexnanostructuresonthepyramidalmicrostructureswereduplicatedfromconcavemicro-andnanostructuremolds.First,aconcavemoldwasfabricated,andthen,theconvexstructurewasreplicatedbyusingtheconvexmold.Theconcavemoldswerefabricatedbysiliconanisotropicwetetchingandaluminumanodizingprocesses,andtheconvexreplicawasfabricatedbyahotembossingprocess,Processofwetetching,First,aconcavepyramidalmicrostructurewasfabricatedbyasiliconanisotropicwetetchingprocessusing20-wt.%potassiumhydroxide(KOH).Siliconnitride(Si3N4)wasusedastheetchingmaskintheKOHetchingprocess,Etchingprocesswasperformedfor20min.Pyramidalmicrostructureswerefabricatedontheentiresurfaceofa4-in.siliconwafer,Afterremovingthesiliconnitridelayer,wesputteredthealuminumonthemicro-patternedsubstrateThetargetthicknessofaluminumwas1m,AnAAOprocesswasperformedonasputteredaluminumlayertofabricatenanostructuresonthemicrostructure,Contact-anglemeasurement,Inthepaper.Theypreparedfourdifferentsurfaces,namely,smoothnanostructured,microstructured,andhierarchicallymicro-nanostructuredSurfaces.Thesefourtypesofsurfaceswerealsochemicallytreatedtoreducethesurfaceenergyusingsilane.Silanewasdepositedbyvacuumvapordepositionprocessinthedesiccator.Then,throughtheContactAngleMetertomeasuredthewatercontactangles,ContactAngleMeter,(a)withoutsilanetreatment:702,(b)withsilanetreatment:1052(c)whenthesurfacewasturnedupsidedownyetthewaterdropletremainedattachedtothesurface.,Waterdropletcontactanglesofsmooth-surfacePMMAsheet,(a)withoutsilanetreatment:1012,(b)withsilanetreatment:1122,and(c)whenthesurfacewasturnedupsidedownyetthewaterdropletremainedattachedtothesurface.,WaterdropletcontactanglesofnanostructuredPMMAsheet,(a)withoutsilanetreatment:1102,(b)withsilanetreatment:1384,and(c)whenthesurfacewasturnedupsidedownyetthewaterdropletremainedattachedtothesurface,WaterdropletcontactanglesofmicrostructuredPMMAsheet,(a)withoutsilanetreatment:1342,(b)withsilanetreatment:1592,and(c)whenthewaterdropletremainedattachedtothesurfaceandretaineditssphericalshapeeventhoughthesurfacewasturnedupsidedown.,Waterdropletcontactanglesofhierarchicalmicro-andnanostructuredPMMAsheet,Conclusion,Insummary,Inthepapertheypresentthefabricationofanartificialrosepetalcomposedofhierarchicalmicro-andnanostructuresonaPMMAsurface.Theconcavemoldofhierarchicalmicro-andnanostructureswasfabricatedbyusingacombinationofsiliconanisotropicwetetchingandaluminumanodizingprocessesandtheconvexreplicaofhierarchicalmicro-andnanostructureswasduplicatedbyusingahotembossingproces