self_healing PvdfFilm MolecularSelfAssembly CP-AFM GranadaUniv PvdfBead kelvin probe force microscopy Protein Wonseok GalliumPhosphide AIN Defect PolyimideFilm SKKU Graphene Steps WPlug 2d_materials SetpointMode ring shape StrontiumTitanate dichalcogenide AM_KPFM Photovoltaics Chungnam_National_University HOPG mechanical property semifluorinated_alkanes Jason flakes ElectrostaticForceMicroscopy Hafnia Etch Cobalt-dopedIronOxide PrCurve