hetero_structure PatternedSapphireSubstrat DNA GranadaUniv NUS KPFM Edwin graphene_hybrid ContactModeDots TemperatureControllerAFM Water LithiumNiobate OpticalElement plastics LiNbO3 Kevlar nanomechanical Scratch Granada HardDiskMedia Tapping temp_control Scanning_Thermal_Microscopy WWafer Alkane Permalloy Chromium BismuthVanadate Non-ContactMode TransitionMetal OpticalWaveguide FrictionalForceMicroscopy piezoelectric force microscopy OxideLayer dichalcogenide