Oxidation Etch Sapphire Sperm Growth kelvin probe force microscopy AtomicSteps Trench Ecoli oxide_layer SingleLayer Formamidinium_lead_iodide HexacontaneFilm Ni-FeAlloy TemperatureControllerAFM CopperFoil Molybdenum_disulfide PDMS temp_control Styrene Fluoride PvdfBead PatternedSapphireSubstrat Ni81Fe19 AEAPDES Al2O3 Blend STO PhthalocyaninePraseodymium PVAP3HT Modulus Optic SingleCrystal Polymer TransitionMetal