Boundary NCM\ ForceDistanceSpectroscopy NiFe molecules Hysteresys Boron Piranha polymeric_arrays NUS_Physics ULCA Etch MechanicalProperties Tin disulfide hetero_structure NUSNNI tip_bias_mode SKPM Al2O3 Platinum Magnetic Force Microscopy Topography high_resolution GaN Gallium_Arsenide Ferrite norganic Conduct MonoLayer ScratchMode Force-distance Protein membrane BlockCopolymer MeltingPoint