PtfeMembrane Polyimide Etch Sulfur fluoroaalkane dichalcogenide mechanical property Chrome STM Praseodymium MoS2 Resistance Yeditepe_University Techcomp EFM hard_disk DOE single_layer cannabinoid StrontiumTitanate ConductingPolymer HardDisk NTU Step Lanthanum_aluminate SurfaceOxidation HighAspect HexagonalBoronNitride SiliconeOxide HexacontaneFilm Writing contact SiWafer NtuEee Pore