neodymium_magnets PolyvinylAcetate ForceDistanceSpectroscopy AtomicSteps MolybdenumDisulfide AdhesionEnergy Piranha mechanical property BreastCancerCell 2-vinylpyridine SThM NCM IIT-chennai Cell Piezoelectric Conductive AFM UnivCollegeLondon AM-KPFM graphene_hybrid Friction Reading 3-hexylthiophene Aggregated_molecules LiftMode SingleCrystal ferromagnetic SiliconOxide TipBiasMode TemperatureControllerStage NUS Tungsten Photovoltaics Hysteresys PtfeFilter gallium_nitride