kelvin probe force microscopy BiasMode GalliumPhosphide blended polymers PolyimideFilm Vac HexacontaneFilm PFM FrictionalForce TyphimuriumBiofilm food MembraneFilter PANI Layer MfmPhase BoronNitride Electical&Electronics LiquidImaging Yttria_stabilized_Zirconia plastics Friction HighAcpectRatio India block_copolymer StainlessSteel AnodizedAluminumOxide PtfeMembrane LateralPFM Co/Cr/Pt Polydimethylsiloxane Boron MagneticForceMicroscopy conductive BariumTitanate Oxidation