2d_materials Optical flakes FailureAnalysis MultiferroicMaterials Growing Morphology TungstenThinFilmDeposition dichalcogenide molecular_self_assembly Inorganic_Compound AtomicLayer FrictionalForceMicroscopy polyvinyl acetate Collagen HfO2 mechanical_property IndiumTinOxide PECurve Al2O3 AdhesionEnergy Alloy ForceDistanceSpectroscopy TiO2 Stiffness Metal-organicComplex HydroGel Tungsten Polyvinylidene_fluoride LateralForce Topography Epoxy LMF tip_bias_mode NTU